A2 POWER UPGRADES: GTI & GLI, Golfs & Jettas

 Latest Update: Jan 1, 2001

I collected a bunch of info on engine power upgrades for the A2 GTI/GLI. See also the other *_Power_Upgrades, the collins files, & the Performance FAQ.This archive does not cover the G60 and VR6 equipped cars.

Jan


Brief Summary

85-92 8VGolfs/Jettas:
The biggest gain can be had with a better down pipe and exhaust system.
85 GTI:
Change ignition map by cutting wire #11?? on the ignition control unit and grounding #3 (which was connected to #11). Yields 2 HP additional, torque peak occurring at a lower rpm. See also 85-87 GTI for additional power.
85-87 GTI: KE-Jetronics:
Advance ignition idle timing to 12 degrees BTDC or until knock. (factory specifies 6 degrees +/- 2). Gains 5-8 HP with >= 92 octane fuel, very noticeable at the low end. Note, it may reduce the life of your catalytic converter.
90-92 16V GTI/GLI:
Motronic Power chips from Autothority & APS.
See also the Performance FAQs for additional references.



 

Article: 35363 of rec.autos.vw
From: mrkim@apollo.adcom.uci.edu (Michael Kim)
Subject: Chips for /// cars
Date: 11 Jul 1994 18:41:03 GMT

            Q: Would anyone mind posting some numbers here? What are typical prices?

What are typical power increases you can expect (and what happens to the MPG?)?

A: I've got a '91 GLI, with Neuspeed's P-Chip.. Purchased at $190. MSR is $250 per APS. HP gains are (according to Aaron Neumann) 7hp. MPG through personal experience) down modestly 2 MPG highway, no change city. High end is boosted considerably. Still pulling quite well up at 115mph. Redline is moved from 6700 up to near 7500(?). In town driving feels a bit easier, read more torque.



Article: 28101 of rec.autos.vw
From: where@maple.circa.ufl.edu
Subject: [W] GTI Tuning
Date: 9 Mar 1994 16:20:53 GMT

You asked what the differences between an '85 Golf and Golf-GTI were? '85 Golf=~85Hp 8.5:1 Compression Ratio, standard Hall sender Electronic Ignition, Bosch K-Lambda Jetronic fuel injection. '85 Golf-GTI=100Hp 10.0:1 Compression ratio, Knock sensing ignition system, Bosch KE-Jetronic (3 wire O2 sensor) fuel injection.

Ok, you asked what difference does the modification that can be done to the '85 Golf-GTI actually do? Well, I've done it, and here's what it is and what it does: The modification consists of cutting the #3 to #11 ground wire within the harness connector for the Knock Sensing Computer. This modification alters the timing maps used when advancing the engine timing. I haven't actually checked closely to see where the changes are but I do know that they change. One redily noticeable point is that the maximum advance moves from 14BTDC to 16BTDC. One reported drawback to this modification is that you have to run 93 Octane gas. I haven't tested this thuroughly, but I will say that it really likes the 93 Octane gas. One minor modification to the above is to route an end of the wire youare cutting out to the outside of the connector, then to install a smallalligator clip to the end of the #11 wire and ground it when you want to run "Cheap Gas". By doing this I can "unmodify" my car by opening the hood and hooking my #11 wire to a ground (conveniently the end of the #3 wire).

Article: 28275 of rec.autos.vw
From: stulen_j@qis.dofasco.ca
Subject: GTI Tuning
Date: 11 Mar 94 16:31:54 EST
 
  Q: I'm considering chip tuning my Golf GLI '85. Does anyone have any experience with that kind of tuning? I have heard that it's a rather straightforward thing to do, should give about 10-15 percent more horse power, e.g. 112 -> 125-130?

A: OK, lets get this straight. According to my GTI expertise, you can not 'chip' any 8V GTI/GLI prior to 1990 (when they went to Digifant injection. The 85 to 89 8V GTI/GLI/GT had CIS-E injection and a separate knock sensor ignition system. The knock-sensor computer cannot be modified (I've opened one up to look). The CIS-E computer alone cannot make hp gains. The 16V GTIs had motronic injection (combined gas/spark functionality) since 87, so maybe they can be 'chipped'. The 2.0l GTI 16V with the latest Motronic system can be 'chipped' as can Corrados. To my knowledge, you can only 'chip' a car that has a single engine computer controlling both spark and gas delivery (and manifold pressure, a la turbo), such systems are Digifant and Motronic.

End of story.



Article: 35958 of rec.autos.vw
From: satan@cml.com
Subject: Chips for /// cars, What's so great about chip

Date: Wed, 20 Jul 94 07:27:50 EST

Q: No shit, you'd think car manufacturers spend millions on their CPU firmware, howís a little motronic-hacker gonna be able to improve on what Today's (not saying older) computer-modeled designs? Other than ruin your cat maybe

Car design is a series of compromises and tradeoffs. The manufacturers design their cars with a specific set of buyers, laws, and environmental issues in mind. You, on the other hand, might prefer a different set of compromises.

For instance, VW might think that their buyers, in general, are willing to sacrifice a little power in order to pay less for fuel (87 octane Vs. 93 octane). You, on the other hand, might be willing to pay for the fuel, and would like your engine to be optimized for it.

A: Well all I can say is wow! I installed a Advanced Motorsports Power Prom in my '91 2.0L 16v and I am very pleased with the difference. No bogginess when starting, more torque, and at around 4-5000, it becomes two hands on the wheel fun. Really noticeable difference at the cost of some gas I'm sure but much more pleasing to drive.

If you call Marc at Advanced, he will tell you what he does to the chip, they have a FULL TIME programmer, and don't use voodoo magic or untrained people or claim unreasonable 18hp gains like Superchips does. Your factory diagnostics still functions, and this chip is always learning via lambda sensor, so will adapt further if cams and a free breathing exhaust are installed. Its the best money I've ever spent on this car, and has given it new LIFE!!!

By next week I hope to have a pair of Schrick 268 inlet/exhaust cams in, and will report on the results. And later this summer, when the importer GTA in Montreal gets their poo together, I'll install the Devil stainless exhaust, which by the way looks amazing.

Martyn Kerluk'91 GTI 2.0 L 16v

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Sender: "MICHAEL H. CHIN" <MHC@ussu.Ciba.Com>
Subject: -- More VW TidBits - Autotech Power Module --

VW's generally tend to run lean in the upper part of the power band (Around 5000 RPM +) and modified engines run even leaner - the fuel becomes the limiting factor in the fuel/air ratio. The Power Module is an electronic device developed for '85> VW's with KE-Jetronic/Digifant FI to deliver the correct amount of fuel when needed. Both engine speed and load is monitored to determine the correct amount of fuel needed, then the Power Module adjusts the current load sent by the injection control to the electromagnetic pressure actuator which controls fuel distribution to the individual injectors. This modified current load signals the fuel distributor to increase the fuel supply.

The Power Module has 7 selectable fuel curves that control peak fuel delivery. Finer adjustments can be made by a tuner or yourself if you are familiar with adjusting currents using a potentiometer. Gains range from 4 to 14 HP, depending on the type(s) of engine modifications. Installation can be performed in 30 minutes. The Power Module is an easy, inexpensive ($150) way to gain more performance.

Currently, the Power Module is installed on my '89 1.8L 16V GTI which has the Tectonics Stainless Steel Exhaust system from the catalytic converter back. No longer does the power band seem to plateau at 5000+ RPM - it keeps climbing smoothly to redline! Actually, you feel the added fuel boost at 5000 RPM - it's like a mini turbo kicking in. It should do wonders when cams are put in and when the displacement is increased. Highly recommended!!! ---------------------------------------------------------------------

From: apaul@kilo.engr.mun.ca (Anthony Paul)
Subject: Got a "chip" for my '90 8v GTI!
Date: Tue, 6 Jul 1993 18:53:07 GMT

I just got a "Superchip" for my '90 GTI 8v. The company is called Superchip, and they are located in Florida. First impressions: Not much of a noticeable difference, maybe in the high end. Here in Canada, most places sell three different octane grades, I've always been using the middle grade. Next empty tank, I'll try the highest octane, hopefully then I can see some significant difference.

More news then...Anthony Paul

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Article: 44027 of rec.autos.vw
From: kafka@cats.ucsc.edu (Gary Andrew Yuen)
Subject: 94 Golf GTI 2.0 8V
Date: 23 Nov 1994 00:49:38 GMT

ritchm@aol.com (RitchM):

"I have a 1994 Golf LE which is supposed to be the American version of the GTI (GTI body kit, Twin bulb headlights, wider tires set on the Orlando rims, sport seats, 5 speed, etc.). So far I have gotten rid of the factory air box and replaced it with a Neuspeed/K&N P-flow air filter for 5HP extra, you can definitely feel the extra boost in the upper RPM range. There are also chips available that will add extra horsepower, which I plan to add next. These are a couple of easy, not to expensive ways to add HP to your Golf."

One thing that surprised me was the article in the current EuroSport Car zine. There was an article on budget VW performance and they did some testing with the P-Flow, P-Chip, and Eurosport Exhaust on the same golf you had. They had 0-60 numbers, which were something, like this: (can't remember exactly)

Stock: 9.68

P-Chip: 8.6 or something like that

P-Chip, P-Flow, & Exhaust, 8.3

I didn't think the P-Chip would make that much of a difference. I also thought the P-Flow would make more of a difference. Maybe the exhaust wasn't so great. Gary

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Article: 50628 of rec.autos.vw
From: martynk@io.org (Martyn Kerluk)
Subject: speed bolt ons to go good ní fast ní get speeding tickets
Date: 7 Feb 1995 23:53:17 GMT

I have been compiling data since last summer when I started actively bolting on goodies to make my car go faster, while thinking cost/long term wearability and emissions. Here are some findings, probably not that surprising to most 16v VW nerds, but I provide them just the same... 1) Motronic Chip Enhancement, i.e. new E-PROM Why?

Increase RPM rev limit. It is useless to add anything else without this limit increased because, all the bolt ons will add power >5500 RPM. Also, the chip will help torque, which you will inevitably lose slightly once bolt ons are fitted. And, the chip will aid in increased fuel requirements that your snappy engine will want.

Note: Watch your timing. Make sure your timing is set correctly, 6 Degrees is what my chip manufacturer recommends. Anything awry of that, and ping n knock will pay a visit.

2) Exhaust The engine will need to breathe. Try cycling up a hill while smoking a ciggy. Even though you may have shapely sexy racers legs, your lungs are saying, "Ugh Ugh"A) Get a well-designed header. B) Enlarge the middle pipe-connecting header to rear muffler. C) Get a GOOD exhaust that will let you _remove_ the resonator and NOT sound like a jet engine. D) Get a K&N air filter

E) Do the air filter mod (see FAQ.)

3) Camshafts/knockenwellen (SP?)

Install a pair of Schrick 268's and watch magic happen. With the upper RPM rev limit removed and exhuast mods performed, you will be able to rev past 5500 RPM without the engine running out of breath like it will stock. It just keeps on pulling hard up until 7200 RPM.

Note: These babies are good but expensive. And in my humble opinion, Schrick is the best.

4) European Intake Manifold The 50mm intake ports on this, are 10mm larger than ours are. This ends up providing another 5-7 HP at the cost of very little torque loss. 5) Port n Polish A mild street port with or without match porting the intake manifold will be the icing on the cake, and will ensure that short of a turbo charger, you have made a very fast car.

Buy an alarm with fuel or ignition cuttoff, and go hunt Corrados :) Take it easy Corrado owners, you have more torque, I know, so chill already.....

NOTE: The above mods, guaranteed will total up to 170-175HP.

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Article: 28273 of rec.autos.vw
From: kwatson@wv.mentorg.com (Keith Watson)
Subject: [W] GTI Tuning
Date: 10 Mar 1994 19:09:22 GMT

Q: You asked what the differences between an '85 Golf and Golf-GTI were? '85 Golf=~85Hp 8.5:1 Compression Ratio, standard Hall sender Electronic Ignition, Bosch K-Lambda Jetronic fuel injection. '85 Golf-GTI=100Hp 10.0:1 Compression ratio, Knock sensing ignition system, Bosch KE-Jetronic (3 wire O2 sensor) fuel injection. A: Looking through the Bentley manual last night I came up with:

85 Golf (Canada) - CIS

85 Golf (US) - CIS-E

85 GTI - CIS-E with throttle stop switches and knock sensor

86 Golf - CIS with one wire change for California or 49-state cars

86 Golf - CIS-E (appears to be the same as 85 Golf CIS-E)

86-87 GTI 8V

87 Golf GT - CIS-E with throttle stop switches and knock sensor (appears to be same as 85 GTI) 87 Golf - CIS-E (appears to be same as 86 Golf)

87-89 GTI 16V - CIS-E with throttle stop switches and knock sensor

Does anyone have more info on which cars use the same computer?

Ok, you asked what difference does the modification that can be done to the '85 Golf-GTI actually do? Well, I've done it, and here's what it is and what it does: The modification consists of cutting the #3 to #11 ground wires within the harness connector for the Knock Sensing Computer. These modification altars the timing maps used when advancing the engine timing. I haven't actually checked closely to see where the changes are but I do know that they change. One redily noticeable point is that the maximum advance moves from 14BTDC to 16BTDC. One reported drawback to this modification is that you have to run 93 Octane gas. I haven't tested this thoroughly, but I will say that it really likes the 93 Octane gas. ---------------------------------------------------------------------

1.8L 16V Power Module Acceleration Times

From: kwatson@wv.mentorg.com (Keith Watson) 
Date: 1995/12/19


Disclaimer: The following test results are for my car and my engine
setup and will probably be totally different from what you would see
on your car.

Below are the acceleration times I measured for different settings
of the Autotech Power Module installed in my car.  First a little
about this little black box.  It's purpose is to increase the amount
of fuel enrichment when at full throttle and above a certain rpm.
From measurement, yes it does increase the full enrichment signal
and this only takes place above 3500rpm.

The Techtonics Tuning Dyno Stories booklet has dyno results when
the used the power module on a modified 16V engine.  They didn't
publish what the engine mods were.  When the power module was used
there was no difference in the hp graph up to 6000rpm.  There was
about a 15hp increase at 6500rpm and 7000rpm.  TT mentioned that
their engine was running out of fuel at the top end.  This could
also be interpreted as their engine was capable of flowing more air
than the fuel injection system on that engine was capable of keeping
up with.

I used a multimeter to measure the milliamp signal being sent to
the differential fuel pressure regulator to verify the operation
of the power module.  The standard signal at any non-full throttle
settings varies between 9 and 12 mA.  The stock full throttle
enrichment reading on my car is 15.7 mA.  The power module has 7
different settings for the following cars:

  1. stock Fox models
  2. Fox or stock Golf/Jetta low compression engines
  3. stock 8-valve GTI/GLI using catalyst exhausts
  4. as above or with non-cat exhausts
  5. 8-valve motors with bolt-on modifications, such as cam, exhaust, etc., and stock 16-valve engines
  6. large displacement 8-valve engines and slightly modified 16-valve engines
  7. 16-valve engines with extensive modifications, such as camshafts with sport exhausts, 2-liter 16V's should use this position as well
Acceleration figures for my car all taken the same day with no
other modifications made between runs.  All times are in seconds
and are averaged from a few runs each.  There were a total of
43 times taken.

Car: 1987 VW GTI 16V
Engine: stock paper air filter, ported intake manifold, stock cams,
  relieved and ported head, balanced, 1.5mm overbore, ported exhaust
  manifold, 2 1/4" (Techtonics) cat, 2 1/4" Techtonics cat back exhaust
Transmission: stock 16 gear ratios, Quaiffe limited slip
Tires: Yokohama A509, 205/50-15
 
 

  setting        mA    3K-6K rpm 2nd gear   5K - 7K rpm 2nd gear
  -------       ----   ------------------   --------------------
 disconnected   15.7      4.4                  3.8
     3          18.5      4.3                  4.0
     4          21.1      4.4                  4.0
     5          21.9      4.3                  4.0
     6          23.6      4.3                  4.0
     7          24.3      4.5                  4.0


I beleive a better way to measure the effects would be to either use
a chassis dyno or to measure top speed reached on a race track.

The conclusion I have drawn from this that the stock fuel injection
system on my car is able to keep up with the amount of air that my
engine is currently capable of flowing.  I guess it's time to try
a free-flow filter and put on the Schrick cams that are sitting in
my garage.
--
Keith Watson
'87 VW GTI 16V

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Article: 5636 of rec.autos.vw
Subject: GTI rev limiter help
From: ti@bazooka.Altos.COM (Ti Kan)
Date: 30 May 92 16:03:56 GMT

You are in luck. The '85 and '86 ignition computer module (officially known as the "knock sensor control unit") is the same part. So you don't need to change the ignition computer. There is no "adjustment" per se either. You can switch to the '86 ignition map just by cutting one wire. On the ignition computer, there is a brown wire (18 gauge) connected to pin 3. This leads to pin 11, and eventually goes to ground. Snip the wire at pin 3 and insulate it. This converts your car to the '86 spec.

I think I should elaborate a little more here with ASCII graphics to avoid confusion:

|    Ignition computer   |
|                        |
+----- 11 ------- 3 -----+
       |          /|
        +----X---+ |
                   |
      X = cut here |
                  GND
DISCLAIMER: If you don't know exactly what you're doing, don't attempt this conversion. Improperly done, expensive damage can result! Again, I emphasize this point.



Article: 5591 of rec.autos.vw
Subject: GTI rev limiter help
From: ti@bazooka.Altos.COM (Ti Kan)
Date: 29 May 92 16:32:16 GMT According to the Bentley manual, my '86 GTI's rev limiter should come on at 6650 rpm +- 50 rpm. Instead, mine comes on around 6200 rpm, which is what an '85 GTI's rev limiter does.

This is true. The '85 GTI/GLI uses a slightly less aggressive digital ignition map, has a little less horsepower/torque than the '86, and has a lower rev-limiter rpm. The '85 setting does have the advantage that it tolerates low-octane fuel a little better. The '86 ignition map has been called the "Audi map" by VW&Porsche magazine because Audi uses the more aggressive map starting in 1985 on the U.S.-spec 4000S.

Q: Is there anyway that I can check if it can be adjusted? Or to find out if somehow my engine computer is from '85? The car was purchased in Feb 86, and was manufactured in late 85.

A: You are in luck. The '85 and '86 ignition computer module (officially known as the "knock sensor control unit") is the same part. So you don't need to change the ignition computer. There is no "adjustment" per se either. You can switch to the '86 ignition map just by cutting one wire. On the ignition computer, there is a brown wire (18 gauge) connected to pin 3. This leads to pin 11, and eventually goes to ground. Snip the wire at pin 3 and insulate it. This converts your car to the '86 spec.

Since you have the Bentley manual, just compare the wiring diagram between the '85 GTI and the '86 GTI under "Electronic Engine Control" and you'll see the difference that I just described.

DISCLAIMER: If you don't know exactly what you're doing, don't attempt this conversion. Improperly done, expensive damage can result!

Happy fahrvergnugen...


Article: 51821 of rec.autos.vw
From: jhamill@tiac.net (John Hamill)
Subject: A2 Golf performance chips?
Date: Thu, 23 Feb 1995 00:17:24

If you have a Digifant (or Digicrap, Digifuck whatever) car (pretty much all Golf Jettas GTI 1.8 8v 1988-92), I would forget about modifying it. The brain doesn't have a socketed EPROM that you can replace. It's basically an economy injection VW developed to save money. There is some company now making a P-flow, and you can do the exhaust, but you are limited by a fixed injection system. A Motronic or older CIS system is the way to go for a project car that you want to make power with. CIS or CIS-E can support quite a bit of modification to the engine with no alteration(s) to the injection itself.

Article: 4474 of rec.autos.vw
Subject: 1.8l,16v Power Upgrades
From: Ripcord <bpp2@po.cwru.edu>
Date: 14 Apr 1995 00:29:26 GMT Q: I just got throught reading the article in the new EC (April or May '95) about the new heads desinged for the 1.8l engines. I thought cool, the 1.8's aren't completely forgotten I _can_ hod rod my car a little. The article talks about the head begin a great bolt on improvement for the 16v engines. Great. Then the caveat: Reccomended only for use on racing engines with different valves, cam...blah blah

What the hell! is it a bolt on or not? or is it just one part of a performance package? it seems the later.

My question then, still remains. What power upgrade options do I have? I've got the 1.8l 16v with CIS-E injection system. I can't chip it, I can't get a new throttle body (at least haven't seen one) no intake mods available. I am basically looking to increase low-end torque, as I don't race, the top end can still get me into plenty of trouble with the local athorties. I've got an Leistritz exhuast (cat back). I just want to get a little more boost off the line.

Just out of curiosity how do you like the Liestritz exhaust? A: There are really no mods, short of increase displacement, that increase bottom end torque in the 1.8L 16V motors. You said hadn't seen any intake mods or larger throttle bodies, well Ron's Parts offers 50mm intake runners on their ported intakes. This is one of the worst things to add however if youíre trying to increase bottom end power. Even in the highly modified 2l cars this one makes the power curve peaky. The throttle body though may offer some advantage, but noone I know has tested one on a 1.8L 16V. Velocity Tuning offers these bored out throttle bodies and their not cheap ($309 and up w/exch.) Autotech offers a power module, which richens the fuel mixture at higher revs, but again this doesn't help bottom end torque. Nearly every part offered for the 1.8l 16V-increase top-end power at the expense of bottom end power. These engines are already peaky, anymore so and they become very anemic at low revs. As for the Leistritz exhaust system, I have one on my GTI 16V and I really like it. It's constructed very well, sounds great (not to loud), but like all other aftermarket hi-po exhaust system it seems to weigh more and breaks exhausts hangers more frequently. I would strongly recommend them to anyone considering replacing their exhaust system.
 
Jeff Brown 88 GTI 16V (mildy modified)

jlb14@po.cwru.edu

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Article: 4508 of rec.autos.vw
Subject: Turbo for A2 8v?
From: monster16v@aol.com (MONSTER16V)
Date: 15 Apr 1995 12:08:10 -0400
Q: Is it true you can get a turbo for an A2 8v?

A: While we do custom turbo projects for some of our customers, we do not use any turbo kits from New Dimensions or any other vendor. Each turbo car we build uses a short block built for the rigors of that type of application and all components are selected for their ability to withstand the added stress of additional horsepower and heat. While we understand that a custom turbo set-up such as this is not right for everyone, we feel that companies such as ND, among others, are doing an excellent job of building bolt-on turbo systems and therefore have no plans to enter that market or use those products. Jeremy Wolf

Velocity Sport Tuning, Inc.

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Article: 4555 of rec.autos.vw
Subject: 1.8l,16v Power Upgrades
From: bernie@metapro.DIALix.oz.au (Bernd Felsche)
Date: Wed, 12 Apr 1995 05:17:08 GMT

Q: I just got throught reading the article in the new EC (April or May '95) about the new heads desinged for the 1.8l engines. I thought cool, the 1.8's aren't completely forgotten I _can_ hod rod my car a little. My question then, still remains. What power upgrade options do I have? I've got the 1.8l 16v with CIS-E injection system. I can't chip it, I can't get a new throttle body (at least haven't seen one) no intake mods available. I am basically looking to increase low-end torque, as I don't race, the top end can still get me into plenty of trouble with the local athorties. I've got a Leistritz exhaust (cat back). I just want to get a little more boost off the line. VR6? :-) :-) A: You may not be able to buy an intake mod - but you may be able to reduce the intake restriction on the filter housing due to the turns required before it reaches the filter.

If you are patient and resourceful, I think that it should be possibe to use a larger Digifant filter housing, siamesed with your 16V housing top, to increase the filter area. Check for clearance under the bonnet though - especially height. I don't have a 16V to try this on, but a friend's 16V looked like it would cope with the swap. Of course, this *should* only make a difference at higher engine speeds.

If you never plan to go really fast, you can change the final drive ratios to give you more revs/mph in all gears. You'd probably want a specialist to do the modifications though.

Fit an older 16V intake manifold with smaller diameter tracts. The higher flow velocity gives more torque at the bottom end, at the cost of high-end power.

Try advancing the timing on the intake cam. Again, this will cost power at higher rpm.

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Article: 5020 of rec.autos.vw
Subject: Turbo for A2 8v?
From: turbotim@aol.com (TurboTim)
Date: 14 Apr 1995 14:05:15 -0400

I believe the people reading this thread would be interested to know a little history on the VW turbo kits that Reeves sold over a thousand of back in the early to mid 80's. New Dimensions in Santa Clara bought all the tooling, rights and inventory from Reeves back in 1991 and since then have released revised kits based on his original design. ND turbo systems as they are know now have received CARB exemption that allows the kits to be sold and installed in California and will pass the required smog test. In addition ND has just released kits to fit the new 93 and up Golf /// and Jetta /// 4 cylinder. The stage 2 kit is producing over 200 hp, which produces many smiles for the owners. The great advantage is being able to enjoy the low fuel consumption on trips with the needed speed when necessary. ND turbo systems power VWs have been review in 3 national magazines in the last few months. See European Car, Sport Compact Car, and Eurosport Car magazines for these articles. So hope this brings some history to the users of this message area. ** TurboTim **
** Second Generation BBS
** Headquarters for Audi and H20 VW Owners
** (408) 980-8830 (2 lines) 24 hours

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Subject: How to make your VW fast.
Date: Mon, 26 Jul 1999 04:07:29 EDT
From: Audealex@aol.com
To: jan@lipari.usc.edu
 
 

Hi, this is an informative write up for all owners of '85-'92 VW's. I've  already sent this to everyone on the 16V mailing list, and they were very pleased with it. This write up covers what most people don't know how to do:

TUNE THEIR CAR.

Please consider posting this on your website,

Thanks,

Alex.

Subj: How-To make your VW fast.
From: Audealex@AOL.COM
To: a-2_16v@connecticom.com

The following is for cars with CIS-E injection, and Motronic injection. I highly recommend that you only do this if you have some sort of mechanical
knowledge. I also recommend that you get the Bentley service manual, if you do not have one.

If anything is unclear, or seems wrong, please write to me and tell me.
Before doing anything, you need to check all your intake boots, and hoses, and vacuum lines for cracks, tears, or anything that could cause a vacuum leak, since this will affect your fuel mixture reading. If your injector 0-rings are bad, replace them.

You will need a multimeter that can read milliamps, and a long 3mm allen wrench.
Turn to the fuel section of the Bentley. Page 54 gives a brief explanation of the procedure, and pages 73-74 have the adjusting values.

First thing you want to do is to hook up you multimeter inline with the wires going to the differential pressure regulator (DPR). The DPR is on the fuel distributor, on the side facing the engine, NOT the side facing the right fender. It has a two wire connector going to it. There are many ways to go about wiring this up. You can either get the factory test harness (which makes things a lot easier), VW special tool # VW 1315A/1 (order # TV1 315 0A1 25 ZEL), or you can put wire taps in the wires to the connectors, or you can make your own harness, using 02 sensor type connecors. If it's all hooked up, and you start the car, and it's running rough, and the meter is pinned at zero, you probably have the wires switched. Change them around and try again.

If you are using an analogue meter, set it to the 10mA or 25mA scale.
When you check your mixture, your car should be at normal running temperature.

That was the "hard" part. Now that everything is hooked up, start your car.
After just starting the car, your meter will read a constant 8 or 9 mA. Let it sit for a minute, and the reading will start to fluctuate. THIS IS NORMAL.

The reading should be bouncing back and forth consistently. The range of operation is 1-12 milliamps. The reading shouln't be below 1mA, and never above 12mA (if you want your car to run right, at least). The reading should only fluctuate about 2-3 milliamps, for example, the stock setting for a 1.8 16V is 5mA. This means the meter should be jumping between approximately 4 and 6mA, averaging 5mA.

Next thing to remember: the higher the number, the leaner your car is running. The lower the number, the richer the car is running. If your 16V is getting a reading of let's say 10-12mA, it is running too lean. If your 16V is getting a reading of 1-2mA, it's running too rich.

Before actually messing with your mixture adjustment, CHECK for vacuum leaks, because they will throw the reading off. Most of this is pretty straightforward, I hope I'm not making it sound more complicated than it is.

What if your meter reads a constant number, and doesn't fluctuate? The most common cause of that is: a bad oxygen sensor.
What if your meter is hooked up correctly, but is pinned at zero? You car is set WAY, WAY too rich, and should be very sluggish to drive, and have no throttle response. Lean out the mixture slowly, until the reading starts coming up.

Turning the mixture screw clockwise will RICHEN the mixture, and of course turning it counterclockwise will lean it out. Never turn the screw more than an 1/8th of a turn at a time. You will see that it is very sensitive.

I HIGHLY recommend that all mixture checks and adjustments be done at night, so that you get consistent results. This is because the computer adjusts the mixture rich, during the day when it's hotter outside. If you check your car's mixture during the day, and it reads a lower number than what you set it to the previous night, don't worry, it's normal.
 

Stock settings:


1.8 16V-averaging 5mA.
1.8 8V-averaging 10mA
2.0 16V motronic-averaging 2.5mA.

Performance tuning. Even a bone stock motor will benefit from a slightly richer setting. These are the settings I recommend for stock or mildly modified motors. The 16V settings are for maximum power between 4000 and 7000 rpms, so you might lose a little bit of low rpm power. If you would rather have the low-end, simply don't set the car as rich.

1.8 16V-averaging 3-4mA ("bouncing" off of 2.5mA)
1.8 8V-averaging 9mA ("bouncing" off of 8mA)
2.0 16V with CIS-E averaging 3mA ("bouncing" off of 2mA)
2.0 16V motronic - get a performance chip!

(what I mean by "boucing off of", is: the lowest number your reading drops to)

Note: If you put a 2.0L block in your '87 to '89 CIS-E 16V, the first upgrade you should get is an Autotech power module. The stock injection for those years cannot supply the necessary fuel to make the most out of a 2.0L motor, even a bone stock one. If you do not get the power module, your car will simply always be missing out on 5-10hp at high rpms.

All cars will respond slightly differently due to mileage, local elevation, running condition, performance parts,...etc. All the settings I give you, are approximate settings.

Any questions, please e-mail me.
 
 

I explained how to do the fuel mixture adjustment, but maybe I should explain what you are actually doing. I'm going to take the VW fuel injection, and make it sound horribly simple. It will help you in understanding the fuel delivery system of your car. This isn't exactly how the injection works, but if you think of it in this way, you'll understand what you're doing.

Your engine gets fuel in 2 ways, "mechanically" and "electronically". The "mechanical" part, being the fuel mixture adjustment screw, which will supply x amount of fuel. The "electronic" part being the full throttle fuel enrichment switch, which will supply a constant amount of fuel, a. a never changes. It is always the same. a+x = total fuel to your engine. When you adjust the mixture screw, x, you are changing the total amount of fuel going to your engine.

Once again, before the nit-pickers out there start going off, I know this isn't exactly how it works, but I want to put in terms that even non mechanically-inclined people will understand.

Miscellaneous stuff about changing the fuel mixture:


My friend has a CIS-E car, with a 2.0 16V. I have noticed that the fuel mixture is very sensitive. If the car is set at the stock 16V setting of 5mA, it will start up easy, idle nice, and have very good low end power, but not much high rpm power (the car will feel like an 8v motor). The setting that my friend actually runs his car at, 3mA, takes away a little bit of low end, and makes the idle a little less consistent, right after start up. But...this setting kicks ass at high rpm's.

I, once again, highly recommend that after every adjustment of the fuel mixture, you take your car out, and drive it hard. Get a good feel for your car, through the first 3 gears, and at part throttle, and full throttle. Small mixture adjustments will make the most noticeable difference at high rpms, in 3rd gear on the freeway.

Setting the Idle on CIS-E cars.


Note: idle setting will affect throttle response at low rpms.

First thing to know: if you have a motronic 2.0 16V car, you might have an idle screw on your throttle body. Make sure it is screwed in all the way. Motronic idle is completely controlled by the computer, the screw should never be touched.

After checking and setting the fuel mixture on CIS-E cars, you'll want to check and set your idle. If you have the right kind of meter, you can follow the Bentley and do it the "professional" way. Otherwise, here's the home mechanic's way of doing it:

-1st, check to see if you can turn your idle screw with just your fingers. If you can, it probably means the 0-ring on the screw is bad. Go to a hardware store, and get whatever 0-ring fits snugly around the idle screw. If you do not replace a bad 0-ring, your idle will "self-adjust", on a daily basis, and you will come whining to the mailing list.

-Next, make sure your car is warmed up, and let it idle. Now, rev the motor to around 3-4000 rpms, and let off the gas. Watch the tachometer. Your idle should drop fast to about 1400rpms, and then drop slowly to 900rpms. That is a correctly set idle. If your idle "sticks" above 1000rpms for a while, then your idle is set too high. If the tach needle drops below 900 rpms, then jumps back up, past 900 rpms, then your idle is set too low. Turn the screw clockwise to lower the idle, counterclockwise to raise it.

Once the idle is set, I recommend putting a dab of silicone around the idle screw, to make sure it doesn't move.
 

Review:

  1. warm up car
  2. rev engine to 4K rpms
  3. see if: revs drop quickly to 1400, then slowly to 900.
  4. adjust as necessary


Alex Ranarivelo