How to build a relatively inexpensive, reliable, powerful Vr6.

[2a2gtis]

I would do leakdown then decide.

Hmm yeah. That would pinpoint it for me. Its wiser to do a leakdown, than just throw HG at it.
Oh btw paul... you hooked up my best friend with megasquirt board work. The Chevelle guy in Ohio... He's really happy with everything. If I ever go that route, or know anybody else wanting to megasquirt, we'll send them your way

[GTIVRon]

Get yourself a good pressure tester with 2 real gauges.

The ony from Harbor Freight (US General brand) sucks. Forces you to do the test at ~16 PSI and I don't trust the results of the test one bit.

[Tsiqara]

Question about IAT:

Today i have remade my IAT....
I have added some wire to the plug of my IAT and mounted IAT after MAF and between TB. The place is right but the question is:

I haven't used 1.8T IAT. I just used VW 97 2.0 Motor's IAT (Which originally was mounted in FILTER BOX).

So does it make any difference if i install 1.8T IAT or the one i have already installed there??? It's design looks same as 1.8 IAT, it's not closed, not covered in metal etc... a bit shorter...


Thank you

[root beer]

All the mk3 sensors i've seen have been are closed element. If you've got an open element vw sensor, im sure it will be fine.

[need_a_VR6]

ABA is closed element, if you have it mounted in the filter box it won't heatsoak but it also won't react as fast to cold air coming in.

[2a2gtis]

I installed a new fuel pressure regulator today. What a difference! Id say it runs at least 90% of what it did before storage. I'm not going to touch the engine internally for now. It feels like it should be in the high 14's now- hopefully .
Test pipe in tommorrow. Chains & clutch fork will wait another week.


Thanks guys

[2a2gtis]

Theres been alot of questions about the 1.8 t sensor and its location. This might help some
http://forums.vwvortex.com/showthrea....8t-AIT-sensor

[98GTI_VR6]

my intake cannot go where you showed due to the a/c system. My 1998 model gti vr6 has the dryer axactly where you routed your cold air intake! How should i go about getting cold air? I just have a 3in. 45* elbow of pvc between my MAF and my K&N cone air filter. however it isn't in the fender but just above it. also how much of a gain are you talkin from 262 cams to 268's (drc). i am thinkin of gettin a pair of 268 's just want to know the noticable gains...i already have 262's with hd springs, polished head and match ported everything including header flange, and both intake manifolds, lower is polished. i have the bfi stg. 2 chip for the 262's, 10lb flywheel. also just ordered the 1.8t iat sensor and im going to install it on the pvc section of my intake.

thing is i got beat by a z28 camaro like 1998 style.... lt1 with a few bolt ons like intake exhaust, r&p, and msd everything.... got me by 2 cars i want to beat hiim lmao.... (at the track)

[root beer]

Just try to fit a curved intake in there somewhere. The further from the maf the better.

The gains going to 268's will be all over. More torque, more power. Maybe 5-10whp peak? Definitely noticable.

If you want to beat him at the track or otherwise, slicks/diff/ring and pinion will get you there quicker than a power increase.

[need_a_VR6]

I had a turn2 intake on my mk3 with ac. You can get something to fit.

[sk8too]

Just loosen the bolts that hold the drier push the tube into the hole and then snug it back up.

[98GTI_VR6]

Thanks ill try the above recommendations... Btw I have him in a quarter he comes around me in the big end we did a pull from 50-110 n that's where he beat me but my jump at the line destroys him. I really want that ytrtansmission that mjm offers with the 3.98 r+p and the upgraded diferential

[2a2gtis]

Ive got the motor out to do timing chains and some other stuff.
On page 1 its written " Timing is always the last thing i do before starting an engine. If you time it, and let it sit, it can very easily hop a tooth on one cam overnight."
I want to avoid the possibility of this. Could I? ....
Time engine, install it into the chassis. Reconnect everything except, leave the tensioner (bled and submerged) in oil until I'm ready to start the engine.
Thread in the tensioner and start it up?
This would be easier- time wise, for me- I'm thinking I should be fine. Ive never done this before. So I thought I'd ask

[need_a_VR6]

With all the motors I have assembled this has never been an issue. Be sure to use the later spring loaded tensioner bolt on all builds with late model all plastic rear guides.

[GT-Ian]

great thread, there is a lot of helpful info

Thanks Ian

[Hurt]

This thread is so helpful.

[vwhead5223]

I have just spent the last two days....at work reading this thread from front to back. Great thread. Love the idea of the 1.8t iat sensor every little bit counts.

I am curious about a statement that you made in your first post. You stated that headers give no gains. That just seems odd to me. I am currently freshening up a VR for a swap I am doing. I cam across a header for a few bucks. Is it better to just run the stock mani and head (no head machining or mani machining) or run the header?


Thanks in advance.

[root beer]

It does seem odd, doesn't it? For one thing, most of these headers are just poorly thought out, poorly made ebay junk. Another is that these motors don't rev very high, which is usually where a header really shines on most cars.

Headers are lighter than the stock stuff on the positive end.

Try it, and see what you think. It's nothing that you can't change back later.

[mx3autozam]

I have been reading this thread for over a year now. I have slowly done alot of whats in this thread thanks to Root beer and his suggestions. Got it dyno'd yesterday at 175whp./168ft lb and i am very happy with those numbers.

Awesome thread

[Grabbit]

<-------seeking input on average cost of a cylinder head machine work to include:

General rebuild
good valve job
resurface head
Clean up ports

Not looking for anything super hardcore but if I'm taking the head off for new HD valve springs, 268s and lifters I want to go a step beyond general maintenance. Was hoping 3-400 would cover something like this......

[root beer]

That sounds about right. Depends on what parts your man will need to get for you. I've sent heads in that need damn near all the valves.

Thanks for all the positive comments guys

[Grabbit]

I've been experimenting with the whole 1.8t IAT sensor and I have to say that I've gotten mixed results with the sensor in the intake track of a CAI and not in the intake track of a stock airbox. Seems to run better on the OEM IAT in the manifold then these two scenarios. Next step in modifying the manifold to put the 1.8t sensor on the stock location. I'm not sure but the 1.8t was engineered with the sensor after the TB so I have to think this is the best place for it.

Just my .02, anyone else?

[JohnStamos]

I just went to a potentiometer instead of the temp sensor after cleaning up my harness this time.

Logged with Vagcom, and kept decreasing the value til it started pulling timing/registering knock (which it never did, on 93oct, Early C2 Jeff tune) so mines locked at something super low temp wise, as I went til it stopped decreasing the IAT on the scanner, then went up 2 degrees so it wouldn't throw a code for too low IAT reading. No knock issues even in the recent 90*+ weather.



If I remember next time I'm out messing around, I'll log the timing on different temp settings to get an idea of the timing changes occurring.


Honestly though, if you are experiencing a big enough driveability/power difference(especially negative!) by swapping to a 1.8t IAT in the intake tube, you have a different underlying issue, as the change isn't really "buttdyno" significant.


I'd start by logging timing(both actual and from map), knock counts, & IAT on a 3rd gear pull with both setups and see whats going on.

[need_a_VR6]

Dont forget the iat effects the fuel calcs too. Not a big deal until the temp changes and your fuel trims are way off.

[WannabeVWguy]

Dont forget the iat effects the fuel calcs too. Not a big deal until the temp changes and your fuel trims are way off.

I'm getting some detonation and pinging on GIAC 268 software once the car is warm. Even with the 94 octane (10% ethanol) that we have up here in Canada.

I am going to retorque my knock sensors but would it be possible that a 1.8T IAT may help my situation? It has happened even on my old stock motor in the exact same circumstances with this motor. Could never figure it out.

[mx3autozam]

I am going to retorque my knock sensors but would it be possible that a 1.8T IAT may help my situation? It has happened even on my old stock motor in the exact same circumstances with this motor. Could never figure it out.

if anything doing this sensor mod will make it worse as it adds timing

[WannabeVWguy]

Fuel trim is also a factor. Not just timing. As paul mentioned this sensor has an effect on fuel trim so i am just curious if its worth a shot

[JohnStamos]

Dont forget the iat effects the fuel calcs too. Not a big deal until the temp changes and your fuel trims are way off.

Do you happen to have/know what the stock table for it looks like? Like whether they are 2d: IAT/fuel modifier & IAT/Timing modifier, 3d based off load, or something not even close to either. Or know how the ECU calculates it. I figure if anyone knows, that will actually share, you'd be the guy.



I guess I could just not be lazy, and open up the OBD1 .bin and see what it looks like.

[Grabbit]

the change isn't really "buttdyno" significant.

more of a cold start/idle issue. As far as power, I can't tell the difference other than the cheap ebay CAI i got is worse than a OEM paper filtered rado airbox..... Plus it makes the car sound like a single cam vtec motor with an intake

[veersixxx]

Hints & Tips





My '97 did 185 whp/ 183 wtq on a dynojet. But it needs a real tune and some diag i am sure. Eats more oil than bp can spill.

[2a2gtis]

I ran a 14.6368 @ 93.84 2.1934 60' 95 degrees that day (last weds.)
best mpg is 33 mpg around town. About the same on the freeway (ccm trans)
Now I'm no drag racer. I just had to know what it would do. What would 268's and a p&p do with those numbers?
My friends are big drag racers and they said expect 2 to 3 tenths when the temp goes below 60 degrees.
I guess I'm looking for 13's. Im at 2360lbs with me in it (mk2)
I basically did everything here in this thread except the trans work and what I said above. (stock head for now)
Thanks for the help roostbeer
Also to everyone else that has contributed on this thread

[JohnStamos]

Honestly, after your compression numbers, and trap speed, I'd be looking to rering it before dropping money on anything else.

For comparison, I have trapped 94mph, at 2900lbs with me in it, CCM trans, with just exhaust and tune.

[mx3autozam]

Hints & Tips





My '97 did 185 whp/ 183 wtq on a dynojet. But it needs a real tune and some diag i am sure. Eats more oil than bp can spill.

That is the exact same tranny setup i run and its perfect

[2a2gtis]

Honestly, after your compression numbers, and trap speed, I'd be looking to rering it before dropping money on anything else.

For comparison, I have trapped 94mph, at 2900lbs with me in it, CCM trans, with just exhaust and tune.

2900 wow. Hmm. I did the mkiv HG. But have not redone the comp test. Yeah sounds like some time could be made up if it was just tight. Lifes busy now. I'm just happy to be up and running. Ill try to make time. A new test would be interesting. Its easy enough to.

[need_a_VR6]

At that weight something is wrong. I would check comp and if that's fine, cam timing.