FrankM

Hi
have a header from WRXTUNER (www.wrxtuner.com) on order.

They promise a better spool-up due to the design of the Up-pipe.
Look at the dynocharts on their website before and after the installation.

I know one guy with a MY98 who changed from a TD04 to a VF23 and a self-fabricated header who got enormous gains - see dynochart as well (www.wrx-gt.de/dia/325ps.jpg)

Power increase from 255 PS to 325, Torque from 345Nm to 405Nm - after the Unichip-remapping. Boost wast set to 1.1bar.

I am sure that this is not only caused by the VF23!
Frank :-)


[Edited by FrankM - 11/8/2002 12:25:43 PM]

Tiago

Can anyone tell me the best headers for the 98 subaru impreza 2.0 turbo? To give maximum of hp does the headers need to be equal lenght? Where's the best place to buy the headers? Thanks.
Tiago

David_Wallis

what other mods are done?

Tiago

full exaust since turbo, chip, fuel valvue pressure and cone air filter

Nezz10

Sorry to barge in on this thread but I was interested about mine too

MY00, Full HKS exhaust, Scoobymania DP, HKS air filter, Link, Greentune inline octane booster, uprated fuel pump, hybrid turbo and blow off valve coming soon.

What gains if any would I see? I have heard it looses low end but gains at the top ??

nom

Headers are difficult.
Many find the standard headers ported give very good results. They are well matched to the car (if not to the ports ) in that they are tuned for mid-range.
4-2-1 headers will give a good spread of power.
4-1 will typically be more high-end power.
Equal length may or may not make a difference - it's more important that they are tuned. If they are tuned, it may well be to one particular rpm 'point', so great for peak power/track day use, not much fun on the road.
Examples... the PE one seems very well tuned with great results. That is if you have a TD04, which of course is what it was tuned for...
Consistently good results seem to come from the HKS headers & the MRT ones, although I believe these are typically on non-standard turbos (larger than the usual TD04, anyway!) so probably wouldn't suit the TD04 so well!

So, that's what I know about them, and it's all IMHO, naturally

jameswrx

iTrader: (4)

Barging in also

Do ported or performance headers enable maximum boost level at a lower RPM coz of better gas flow to the turbo?

I ask coz I thought I was having trouble with my car not producing it's peak boost til 6,000rpm, but am starting to wonder if it's coz of the standard headers and their lengths before they reach the turbo? Been comparing scooby to my other cars i've had and the characteristics of boost levels seem very different to cossies, gti-r's etc (which have turbo close to engine in exhaust).
James

ricco

Peak boost at 6000 RPM

How much boost are you running, 10bar

jameswrx

iTrader: (4)

I've had enough!
I thought I should get peak at bout 4,000-4,500rpm in 4th but it gets there then creeps up from 0.50bar to 0.89bar just before rev limit. You must of read one of my posts bout this problem!

hades

I believe that most performance headers will actually increase spool up time as they have a bigger internal volume. I can't see (with my limited knowledge) how this would be your problem with your boost levels and that late arrival of boost. 4-1 headers particularly are likely to make things worse. AFAIK, the normal headers are as good as any for achieving early spool up, although they give more power when ported. Aftermarket headers will often give more power at mid-high or high revs, at the expense of spool-up time. I guess that you have a different problem, James, though I don't know what.

nom

Yup, can't see boost creep as having anything to do with headers! All they do in general terms is raise the VE of the engine, which in theory could well reduce the boost (although raise the power).

harvey

iTrader: (48)

Porting your existing O/E cast headers AND up-pipe will make a difference. If you want more power and are prepared to spend the money the actual headers you need depend on what level you are going to with the car and what you want from the car. eg. broad powerband or lots of top end. You can get a lot of advice from :
jack@ionperformance.com
His headers gave me big gains and I now run his turbo. There are several systems in both 4-1 and 4-2-1.

Tiago

I prefer lots of top end, because i want that my car gain more top end speed. My car does in the digital speedometer of 01 Porsche Carrera side-by-side 274km/h. And i still have more 500rpm, but the car don't have the power enough to do it.
Does the aqua made good headers? Does the Grahamgoode have good prices? Where can i find a better place to buy headers? Thanks.
Tiago

dowser

If you can't remap around new headers, then stick to porting the OE ones and fitting a less restrictive up-pipe...IMHO

Without the remap, headers will always be a bit of a compromise - generally moving the powerband higher up the rev range by changing spool characteristics. Even those that don't generally wont have optimal fuelling/timing for the new flow capabilities.

With a remap, they can work wonders.

Richard

Floyd

iTrader: (9)

Interesting about the up pipe. I have both non-expansion up pipe and std. The std IMHO doesn't look as bad for flow as some make out. The non-expansion is smooth all the way and slightly larger internal dia. The std has a slight lip on the internal tube but that's about it. You could smooth this lip but the dia of the feeding pipe looks smaller anyway.

I also thought that maintaining the same smaller dia would help response and spool up speeds?

Mine do not have cats in the up pipe, is so I could understand the need for change. (MY00).

F

nom

THat's what I though too - if you have a cat in the up-pipe, it makes a difference by removing it, but the main reason to change the up-pipe is because the standard one can split on occasion (the flexible thing flexes once too often). A wider up-pipe than standard could conceivably slow the EGs so effect spool-up.
Don't know about the BPM jobbie, though - sounds like they've taken that into account, although that may just be marketing...

harvey

iTrader: (48)

P.S. Should have said that the Ion Performance headers I have fitted (4 into 1) include an up-pipe in their manufacture.

Mark A

iTrader: (1)

Do Ion Performance have a web site ?
And is it accessable outside of America

Mark A

madou

http://www.ionperformance.com

site is just a placeholder, email info@ionperformance.com

P20SPD

iTrader: (1)

could well be!