View Full Version : Rolling road setup for IHI'd 20vt..
Sorry to bend the rules slightly guys, but it'll get more response here, and it's not just so you can all see the power plot...
First off, would anyone be so kind to host it for me ?
It's a 20vt S3 lump in a mk2 golf
Allard intercooler
Big ram air filter (right by the bulkhead at the moment :O)
Huge downpipe and good powerflow system.
The turbos on a jabba manifold and is a IHI VF23..
New S3 bottom end (400 mles on the clock at time of mapping)
It was being mapped by dave walker up in Norfolk, so should be the nuts, i think to be honest he dind't want to push it as the cars a bit of a dog at the moment and it's a new engine...
Max boost was 12psi (sustained from 3700rpm to 7000rpm, then hit the limiter) ATFW power was 255bhp @ 6800rpm, 215lb ft @ 4800rpm..
Looking at bills plot, this seems a little bit poor to me, 3 psi more boost and less power and less torque...
What dya guys with IHI's recon ?
Also, as you'll know, theres the vacuum pipe from the outlet of the turbo, that controls the wastegate, and if you want to run a bleed valve you have to T piece it off from there.. We didnt have a bleed valve, so we made one from some tubing and stuck some carb jets in the end to act as the valve, it worked but the jets couldn't go up in big enough sizes to give a good increase in boost lol, so they were reoved all together.. Surely this should be max boost situation now then (only 12psi at the moment) ?
Or if we put a bleed valve in there, and made a hole that was bigger then the ID of the vacuum tube going to it, would it give more boost still ?
I'm hoping it's that, otherwise it's got to be a weak acuter spring opening prematurly i'd think..
Cheers for any help guys, i know it's a bit of a headfull to work out lol.
Mart.
email the pic to me - mark@seatcupra.net I'll upload it now for you
Mark
ibizacupra
02-10-2003, 08:40
Comparison of IHI, I think the VF22 on mine (23 on MKIV)
http://www.badger5.demon.co.uk/bin/IHI-low-vs-high.jpg
Your torque is quite low IMHO...
Is your cylinder head the large port or small sport?
The MKIV's head is large port and as such with its hybrid large turbo its power delivery is hard from 4K to 8K+
The MKIV does have an extra spring on the actuator to resist creep, but the Ibiza does'nt.
Were you using a solenoid for boost control? or relying on base actuator pressure setting (with/without bleed valve)
Was there a reference on DW's rollers as to their comparison to others like Jabbas or Stealths for actual power otuput.
Bill
ibizacupra
02-10-2003, 08:45
Originally posted by madmk4
Also, as you'll know, theres the vacuum pipe from the outlet of the turbo, that controls the wastegate, and if you want to run a bleed valve you have to T piece it off from there.. We didnt have a bleed valve, so we made one from some tubing and stuck some carb jets in the end to act as the valve, it worked but the jets couldn't go up in big enough sizes to give a good increase in boost lol, so they were reoved all together.. Surely this should be max boost situation now then (only 12psi at the moment) ?
Or if we put a bleed valve in there, and made a hole that was bigger then the ID of the vacuum tube going to it, would it give more boost still ?
I'm hoping it's that, otherwise it's got to be a weak acuter spring opening prematurly i'd think..
Mart.
If you add a bleed valve in the turbo outlet to actuator pipe and bleed air out then yep you will effectively raise the running boost pressure (excluding weak actuator spring)
You not running any programmable boost control then via N75 equivalent I presume.
Bill
Were you using a solenoid for boost control? or relying on base actuator pressure setting (with/without bleed valve)
Relying on the acuter boost pressure setting.
[QUOTE]Was there a reference on DW's rollers as to their comparison to others like Jabbas or Stealths for actual power otuput ?[QUOTE]
Nope, with the amount fo money he's spent on his rollers, he's certain they are fooking accurate..
We don't run any sort of programmable boost control,but you can have it with emerald.
The head is an APY one, so why max boost comes on at around 3700rpm odd is beyond me, i'd suggest a leak somewhere but once max boost is there, it holds nicely to 7k
Cheers for clearing that up Bill, when I get the bleed valve back i'll fit that and see what sort of boost we can run, that way i'll know for sure if the acuter sprng is weak or not upto the job and needs a adjustable item possibly..
The other thing I didnt mention in the original post was the fact that the water temp and air temp into the air filter was very high n the day, and the inlet temp was around 22-30 degrees depending..
Mark: cheers for offering to host the picture, 'll have to e-mail you the graph a bit later when i'm at home, at colege at the moment..
ibizacupra
02-10-2003, 18:16
Originally posted by madmk4
Relying on the acuter boost pressure setting.
[QUOTE]Was there a reference on DW's rollers as to their comparison to others like Jabbas or Stealths for actual power otuput ?[QUOTE]
Nope, with the amount fo money he's spent on his rollers, he's certain they are fooking accurate..
We don't run any sort of programmable boost control,but you can have it with emerald.
The head is an APY one, so why max boost comes on at around 3700rpm odd is beyond me, i'd suggest a leak somewhere but once max boost is there, it holds nicely to 7k
Cheers for clearing that up Bill, when I get the bleed valve back i'll fit that and see what sort of boost we can run, that way i'll know for sure if the acuter sprng is weak or not upto the job and needs a adjustable item possibly..
The other thing I didnt mention in the original post was the fact that the water temp and air temp into the air filter was very high n the day, and the inlet temp was around 22-30 degrees depending..
Mark: cheers for offering to host the picture, 'll have to e-mail you the graph a bit later when i'm at home, at colege at the moment..
APY head? do you mean AYP head a la Ibiza 20VT's..... small port.
Unported? Stock?
I can;t remember the turbo on the Ibiza vs the Golf... VF23 on Golf? ie bigger... but laggier (sp) and spools from 4K rpm on large port. Ibiza was on full chat at 3K rpm on small port prior to porting job done on it. Now 3500rpm.
Air temps are important when using the stock ECU... I don;t know what compensations DW would be using for charge temps... but on a factory car boost is one thing which is would "safe" when too hot, and given your ECU has no means of controlling boost, he would need to do other things to keep things with a safety margin.
regards
bill
Nope, it is an APY head, im sure thats a TT head, and it's totally standard.
I take it your biza runs a standard acuter yea ?
Cheers for the help again bill, cant wait to get the 20vt at donny !
ibizacupra
02-10-2003, 20:13
Originally posted by madmk4
Nope, it is an APY head, im sure thats a TT head, and it's totally standard.
I take it your biza runs a standard acuter yea ?
Cheers for the help again bill, cant wait to get the 20vt at donny !
Smallport then?
So many engine codes it make ya dizzy :p
Std Actuator on Ibiza yea
Tazkenny
03-10-2003, 02:39
The S3 bottom end has a lower compression ratio from the Ibiza...unless Jabba put a thick gasket on?? To me that reads that you will loose out low down put can scope for higher boost to get the BHP.
sorry for stating the obvious
I'm sure Bill told me that he has machined donw pistons in his...
8.8:1 isnt it ?
How could i forget, walking thorugh the ring carpark chattin away about it oggling at the lambo's and the sort :D :p
ibizacupra
04-10-2003, 18:59
Originally posted by Tazkenny
The S3 bottom end has a lower compression ratio from the Ibiza...unless Jabba put a thick gasket on?? To me that reads that you will loose out low down put can scope for higher boost to get the BHP.
sorry for stating the obvious
Aye, mine runs a lower than stock (ibiza) CR. Approx down to 8.8:1 from its 9.5:1 stock figure.
Machined pistons and ceramic coated.
Runs very similar low down torque as before even high to be honest (ignoring the gas flowed head aspect which did change the power delivery) - Lower CR did allow more ignition advance to be run which is nice free horse power. It is more than plain boost which contributes to power figures. Ignition is a key parameter.
No thick gaskets tho ;)
Bill