# Wanted to get the most power out of my 8v, questions, and opinions



## Danger1523 (Dec 16, 2011)

I have a MK2 GTI 8v. I was wondering what the maximum bore is I can do and how much power the stroking out actually does. Also, I was looking at TT for some cams they have, I'm looking for something with a decent Idle, nothing crazy, I suppose that's all personal preference. But I am a newcomer to engine work, and I dont especially understand all of the terminology when trying to select cams. Sorry for being vague and such, thank you


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## antichristonwheels (Jun 14, 2001)

you can go 84.5mm bore in a 1.8 block

85mm in an ABA block


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## Danger1523 (Dec 16, 2011)

What's the difference between ABA and 1.8?


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## antichristonwheels (Jun 14, 2001)

the ABA 2 liter was the replacement for the 1.8 in 93


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## ziddey (Apr 16, 2006)

What are you goals? What year mk2 is it (cis-e or digifant)?
It sounds like your best bet would be simply dropping in a 2l 16v from a 16v mk2 or passat.

If you're cis, you can get good power on the cheap with a small turbo.


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## Danger1523 (Dec 16, 2011)

Sorry for the lack of knowledge. 87'. I want to keep the 8v, and keep it NA, I know it's making things more difficult. Just wanna do it that way. As far as goals, I want it to be a daily driver, but have enough power to have fun with. I doubt I'll track it. Hopefully 200-250whp, I dont know the capabilities of the engine or what exactly I'd need to do


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## ziddey (Apr 16, 2006)

200-250whp with a na 8v :laugh::laugh::laugh::laugh:

87 is cis-e. stock fuel injection system can only provide about 200hp or 160whp. good luck even hitting that na 8v.

cheapest thing you could do for a bit of extra power would be to grab the exhaust manifold, turbo, and downpipe off a turbo diesel mk2.


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## Danger1523 (Dec 16, 2011)

Ok Ok haha. So what are my options. Even for 200. Stroking, cam, different injectors?


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## ziddey (Apr 16, 2006)

you're talking damn near 10k to achieve your goals (if you don't give up / if you can even hit 200), and even then, it sure as hell won't be a "decent idle" or be a daily driver.

all cis injectors flow the same, although there's no point talking injectors until you need em. with what you're talking about, you'd most likely be ditching cis anyway.

unless you've got a ton of experience already, are trying to stay within whatever class, or just won the lottery, it just doesn't make sense. hell, it just doesn't make sense either way.


the 87 has the rd motor, which already has a "decent" cam stock. really, I'd say it'd not really worth it upgrading. Gains won't be huge, especially if you're not willing to go wild and sacrifice idle quality.


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## Danger1523 (Dec 16, 2011)

Alright, thanks. So as far as the turbo, everything would basically bolt up from a Diesel?


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## ziddey (Apr 16, 2006)

do some searching. there were a few huge threads about using mk2 td parts. and of course, if you're actually serious about going that route, you've got a ton of reading to do in general, and you will probably dream of bigger and better. in terms of "simplicity" it's a decent place to start in my opinion.


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## Danger1523 (Dec 16, 2011)

Thanks for all the help, and especially the direction. Much appreciated


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## ziddey (Apr 16, 2006)

don't thank me yet. i'm pretty sure a lot of folks here don't agree with my advice.

http://forums.vwvortex.com/showthread.php?4715667-junk-yard-turboing-DIY-for-ABA-s

there was a big thread but i can't find it at the moment.

bingo:
http://forums.vwvortex.com/showthread.php?544667
http://forums.vwvortex.com/showthread.php?2470020

also look up longitudinal's cis turbo build. if you run out of fueling, you could always go mercedes fuel distributor and add another set of injectors to your intake manifold.


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## ny_fam (Apr 3, 2004)

There a several formulas to get lots more power out of these engines.
Here is another version for NA power.
High performance head work or Eurospec head with real good cam.
Independent throttle bodies attached to proper manifold
11:1 CR & block in good shape
MegaSquirt - electronic fuel injection
This has proven to make over 160 at the wheels.


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## Seax_Smith (Jun 1, 2007)

Danger1523 said:


> I have a MK2 GTI 8v. I was wondering what the maximum bore is I can do and how much power the stroking out actually does. Also, I was looking at TT for some cams they have, I'm looking for something with a decent Idle, nothing crazy, I suppose that's all personal preference. But I am a newcomer to engine work, and I dont especially understand all of the terminology when trying to select cams. Sorry for being vague and such, thank you


Chasing power in a 8 valve is sort of a loosing proposition.

There's a bit that can be done easily and inexpensively to get the most out of a 1.8 8 valve, but the same money into a full ABA or ABA hybrid will get you still more. Either way if you want to get past 130, open you wallet and when it's empty, install a hole in it, or swap in a 2.0, 9A engine (16 valve)

If you are new to Mark II's, build a reliable street car that is fun to drive first, then go after something bigger.

The AutoTech 270 cam is popular for good reasons.

Skip the header (unless its free). the "PF" dual down pipe and manifold are pretty damn good. 

Get a good exhaust on it (60 mm or less). 8valvers loose big with an exhaust which is to large in diameter. Gas speed is much more important.

DO NOT mess with your air box. 

ESC chips are great for Digi II, IF you can find one, but most chips help out digi II.

Get out the dremel and clean up the TB, and intake manifold and dremel to gasket the intake to head connection. Pick up a spare head and do the do some reading and get out the dremel.

So, for starters, AutoTech 270* cam, ESC chipped Digi ECU if you have digi, TT dual resonator exhaust 55mm - 60mm with a Borla, and clean up the intake stream. 

If you have a Digi II car, there is an accord short ram which can be cut to fit to replace the rubber boot from the AFM to the TB. Learn to make it relaible and enjoy it while you figure out which way you actually want to go with it.

If Big HP and torque are to goal, start looking into ABF clone variation.

Big HP is a turboed ABF clone with ABA pistons.

High torque variation is an ABA block, TDI crank and givertake 9A pistons.


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## Jettaboy1884 (Jan 20, 2004)

^ All great replies...

I'm a big fan of the 8v motors, but you have to be realistic when you get into modifying them.

The older Supervee motors (lookup Bertils Engines) were probably pushing 200 Hp, but they have some serious time and money into them, and would hardly be streetable. As someone mentioned, 130 Hp is realistic for a well-built 8v with the common bolt-on's, but the returns for the money diminish pretty fast after there...


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## harrie (Jan 8, 2010)

ive always been told by a friend to first focus on suspension and brakes on these cars first, it makes sense when you start that way. the car feel so much better with even the first upgrade. he knows his car too. while he does have a 16v, you can tell the car is well balanced no matter how hard you get into it.


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## Seax_Smith (Jun 1, 2007)

harrie said:


> ive always been told by a friend to first focus on suspension and brakes on these cars first, it makes sense when you start that way. the car feel so much better with even the first upgrade. he knows his car too. while he does have a 16v, you can tell the car is well balanced no matter how hard you get into it.


The suspension & brakes first thing... not just with Mark II's.

Suspension upgrades you can appreciate no matter what speed or how hard you are driving.

Brake upgrades are the same.

Rule of thumb for most serious modding: Be able to stop it and control it BEFORE you put power into it or you'll have a really cool engine in a very bent car, AND if you're lucky, you'll still be alive and able to extract the engine and start over.


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## udeg47 (Oct 6, 2011)

*turbo*



ziddey said:


> 200-250whp with a na 8v :laugh::laugh::laugh::laugh:
> 
> 87 is cis-e. stock fuel injection system can only provide about 200hp or 160whp. good luck even hitting that na 8v.
> 
> cheapest thing you could do for a bit of extra power would be to grab the exhaust manifold, turbo, and downpipe off a turbo diesel mk2.


 Ok, so what you think about turbo kit from eBay . Do you think that is good idea .eace:


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## ziddey (Apr 16, 2006)

Do your research on parts. There are definitely good parts to be had on ebay for building a turbo setup. As for the turbo itself, you'd have to do a lot of research on that as well. But generally speaking, it may be a better idea to pull one from the junkyard.


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## Glegor (Mar 31, 2008)

ebay turbos (the new cheapo chinese ones) explode if you ask too much of them.. 

if an ebay turbo is your only option, send it off to g-pop shop (or another reputable turbo rebuilder) and have it rebuild with garrett bearings and seals..


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## B4S (Apr 16, 2003)

udeg47 said:


> Ok, so what you think about turbo kit from eBay . Do you think that is good idea .eace:


 It's not a kit, it's a collection of parts that requires hours and hours of fabrication to install. There are no proper 8v turbo kits for the pre-92 cars.


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## novws (Dec 17, 2005)

Don't discard the idea of a 120-130hp MK2 GTI. With a little weight loss, some careful suspension tuning and some brake work, it will be an absolute blast. It may not be the fastest car, but it will be fun and you'll like going this route even more with $4+ dollar-a-gallon gas.


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## Seax_Smith (Jun 1, 2007)

novws said:


> Don't discard the idea of a 120-130hp MK2 GTI. With a little weight loss, some careful suspension tuning and some brake work, it will be an absolute blast. It may not be the fastest car, but it will be fun and you'll like going this route even more with $4+ dollar-a-gallon gas.


 It's even more fun if you keep the outside looking like aged stock.... fun as hell to drive and surprises a whole lot of people.


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## Danger1523 (Dec 16, 2011)

Sorry for taking so long to reply. I've been busy with work and have been spending a lot of time grinding away seam sealer, taking out my dash for a new firewall etc...So I have the motor finally up on the stand, I was going to take it to a Napa to have the head cleaned out...although he wont port and polish it. No big deal I suppose, but now that the engine is apart I'm thinking of going with the most power I get out of it until I go the 16v turbo route. The main thing I'm worrying about is tuning CIS, I dont especially want to get into that and MegaSquirt, if I have to take it somewhere to have it tuned I guess I'll have to do that and waste the money, I'm not sure if doing a different cam would affect tuning, I assume it would. So here it is

Head-I'm going to need a new head for NA I'm supposing that the stock one is a waste
Exhaust-I have a high-flow cat on there, but I have no idea on the rest of the exhaust, previous owner said he spent 900 back in the day on the exhaust but doesn't remember who made it, 
Cam-The current cam is in beautiful condition, but if it isn't providing power, why not replace?

Anything else guys? The current pistons in there are dished, I wasn't expecting them to be since all GTI engines were high comp, unless there's just a high comp head on them with the same bottom end, which wouldn't make sense. Thanks for all the advice


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## boxerfan (Jan 14, 2006)

*CIS is dead easy and very reliable...*

My experience has been with the Audi I5 motors running CIS. I've actually been contmplating how to shoe-horn one into an MK1.

Failing that the amusing idea is to hack off the not needed EM port and block it off to allow the use of the k26 or k24 turbo. I also have a couple of 5-cyl CIS dizzys and have also been contemplating that since it will add a substantial amount of fuel as an extra injector, perhaps pressure switched.

Similar to the VW 8V, the 10V I5 is not a cross-flow head and is prone to detonation. The easiest way to get more power is really to do as others have already suggested, especially since you seem to be fairly new to all this. The best bang/buch for an Audi I5 is to go with the 20VT motor instead of the 10VT.

A mild cam will help an 8V as would solid lifters, but then you must adjust them.

And lastly, returning to the start, CIS is VERY reliable. Once you have your zero and basic settings done (DON'T mess with it unless you buy a manual and fully understand things) the final adjustments are very simple. That's my $0.02 and I hope it helps.


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## ny_fam (Apr 3, 2004)

Here is a post I did for CIS based cars, gives you the ability to tune the air /fuel ratio to where your engine will make the most power. The CIS lamba aka K-Jet is not easily for max power, this is why many switch to CIS basic. CIS basic allows you to tune the CIS.

This CIS mod allows you to use a computer to tune for max power and tune for reasonable gas mileage too.

http://forums.vwvortex.com/showthre...a-wideband-controller&p=76610896#post76610896


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## c0mmon (Dec 30, 2003)

if you want power, ditch the 8v


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## Danger1523 (Dec 16, 2011)

I'm just looking to get the most out of my 8v while it's in there. I plan on doing a 1.8t 16v in the future.


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