Which is the best engine to go with ITB?

Hmmmm ask RobT the answer to that one, his is ? (9A/6A or another) not sure if he had a high spec ABF in before that though

I've had all Three Engines in my MK1 and i know which i prefer

 

Refering back to Chrismc's comments.
I was the previous owner of his car and had that exact engine spec running on K-jet before fitting the Jenvey set up bought from Bill as a complete kit including DTA ecu. I had it mapped by Vince at stealth who made the comment that all i had gained was noise. The power was no different. Only when i removed the crap magnex exhaust and put a supersprint race system followed my another rollers session did Vince finally decide he liked the engine. I cant remember the figures now but i certainly never got the increase in top bhp that Bill claims.
That's not telling the whole story though because on the road the car was a lot stronger than on k-jet. The throttle response was fantastic which made it real fun on track. Ian B drove it and loved it.
I sold the car for personal reasons but had i kept it i probably would have ended up doing more engine work to make the most of the throttle bodies just as Chris suggests.

 

To Corect your misquoting of me Matt... I personally claim NOTHING for tbodies as the power is entirely down to the engine onto which you bolt them onto (ie I cant predict what an engine will produce, not having seen it, but I can say what others have told me they gained)... The engine which if its not capable of breathing more air like the 45mm bodies can allow, then no surprises, there is not going to be much of a gain. Losses are even likley in torque if its not mechanically up to the breathing job.

Other gains in throttle response however over k-jet are night and day.

My own Jetta gained 22bhp, the highest bolt on gain I have been told was 37bhp on a customers engine.

this is why I dont sell bodies (knowingly) to people with std engines, who "think" they want bodies.

Minimum spec to me to bother thinking about bodies, is flowed head, cams (not docile mild ones) and for actual power gains, a rise in compression ratio.. The sum of the parts really start to get gains then.

 

experiment currently ongoing to see if this head will work on a 2L bottom end from older engines

 

mine is a short rod engine, never had an ABF in there, revs to 8700 on a forged vw crank no probs at all

cannot see any reason why an ABF wouldn't be just the same

 

Danster, I was all set for using the deisel crank in an ADR engine with modded 9a pistons and gixxer T-bodies. However, life got in the way, and we never got as far as a dry build.

Sold all the other bits, but still have the T-bodies under my desk

 

Sweeeeeeet! Any reason for not using the whole engine? Transmission issues possibly?

Gurds

 

Now we're talking of using the 20v motor I'm suprised Graham Vanstones engine hasn't been thrown into the ring. He built this years ago and from memory it made good figures but was very expensive.

Chris Eyre should remember this car.

 

I do - I saw Graham out at the 'Ring last weekend.

From recollection it was originally built on a 16v block, and was later rebuilt to a higher spec, in a different block again (engine spec - click) - and there was a notable increase in power.

The problem with it is it was undeniably expensive, and is probably beyond the remit of this thread.

 

Agreed, I remeber talking to an "engine builder" in Bristol about the motor and he told me the approx. cost............My ar$e nearly dropped off.

Cracking car though.

 

ITBs look very cool, but if you want a fast road engine, you may be happier with a turbo or a bigger capacity unit such as a vr6.

look at cost/bhp before jumping into ITBs

 

Blocks are totally different meaning older-type ancillaries wont bolt on anymore.

Issue presently is that these FSI heads use roller rockers for the cams, rather than direct valve actuation on std valvers, and the rockers dont seem to be compatible with high lift 'race' cams - solutions are in process though

Std valve sizes are 34mm in, 28mm out, but with a much nicer port shapes and because valves are inclined, much more potential for bigger valves

(edit-valver valves are 32/28 for comparison)

 

Bit new for me this stuff RobT.

But, I believe the later TSFI heads designed for the 06X blocks use the extra 3 oil drains at the rear of the head that are not present on early 8 and 16v blocks. There may well be far larger differences too.
However the ADR 20v block (intermediate shaft type) has these extra holes to the rear and may allow fitment of the later head.
ADR runs 81mm bore and 86mm stroke, so it would be like building a short block 2.0 with the crank swap to 92.8mm and rebore to 82.5mm.

 

Hi guys

From what I know having longer rods is better for higher revs engine
Shorter one better for the torque but limited on the revs as it s augment piston acceleration
having a good rapport stroke / rod lenght is important
That's why I would go for a tall bloc
Which make even better for a bigger stroke diesel crank

Now regarding the discussion of gaining HP with cam without increasing the revs
I m not to sure
Most of cam move or expend the power band
which mean different revs and most of time higher revs

Now regarding the new head it was about time that vw came with a nicely designed 16 valves head
When the first vw 16 valves production head came out most of the big tuners and engine builders
Was disgusted by the design mainly the vertical exhaust valve making a bad 90 deg bent in the exhaust track

Now for it s tunability the came could be regrind
or just having longer rocker to augment the lift (like on the good old push rods) could make good change
But the rollers make more sens then the old follower ( less friction )

Romain

 

More info from a previous detailled discussion on crank/rod ratios here:

http://www.clubgti.co.uk/forum/showthread.php?t=214020&page=3

http://www.clubgti.co.uk/forum/showthread.php?t=214020&page=4

 

We are going back a few years Bill but you knew my engine spec so as far as i'm concerned i am not misquoting you at all. The point of my post was to make the point from experience to people that dont have the experience that big power gains should not be expected. ITB's are an ideal starting point for further improvements where the K-jet starts to struggle.
I will however add once again that the kit you supplied me made my engine something it wasn't on a healthy k-jet system. Anyone who drove it, heard it and saw the flames from the exhaust loved it

 

Cheers for the link
Really interesting

 

I think the gains from the ITBs are all dependant on the original spec of the engine in original plenum injection form

Bolting them onto an otherwise internally stock ABF motor with some good management and mapping will liberate a healthy gain over stock figures. Just set a sensible rev limit...

If the engine has already been worked with flowed head/cams and a good tune, then the addition of ITBs is going to yield less of a % gain.

To really start opening up a decent power gain over the stronger plenum injected cars (ianb's being a superb example) then the engine needs more compression, more revs and more aggressive cams.

The problem then is it starts getting seriously expensive if you want any kind of longevity from the engine. Steel bottom ends, solid lifters, new pistons, machining, etc etc

I actually think the engine on B6 had more to give. A bit more advance on the cams to move peak power down to around 7k would have gained it some further mid-range punch.

Ultimately, close on a true 200bhp from a stock compression 2L block wasn't too shabby

 

The one thing I am consistent on is what I tell people, and the above examples are EXACTLY what I say.. I NEVER say what power people will get, as its all down to the particular engine spec, which I never see. the customer gains, reported back to me are the only figures I can quote, and the range in gains varies a lot. My own jetta example being one of the lower gains (22bhp) seen, BUT, as I said throttle response was night and day different for the better on bodies/dta combo, as you would expect from a modern fuel injection system. compression is the key to valver power.

 

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