Hi,

Just looking through an old [cough] [cough] revs magazine NOV 2002, and noticed a company with an add who sell impreza tubular headers/exhaust manifold for £595...

They have a site but it doesnt seem to do much www.icon-performance.com

There number is: 01753 651356

here is a pic from the mag..!

http://upload.turbosport.co.uk/getpi...9151562313.jpg


Dan:D:D:D

I may be getting the perspetive wrong here, but... if that's them, I'm not sure it's for the same 'Impreza' that we tend to talk about on here... :rolleyes: or if it is, it is going about it all in an inventive new fashion!

For cheap 'new' headers, why not port the oem ones? It's not really worth dabbling with some unproven design - things can get worse than the oem ones, believe it or not! :)

[Edited by nom - 11/27/2002 7:35:59 PM]

could these be for the 'sport'...???? and not the turbo...??

Dan:D:D

Think that could be Ion performance 4:1 headers ?? As used on Harvey 420 bhp beast :)

Whilst they may work well on a car with X specification, it may be that they are a bit hit and miss on car with Y specification - I gather there are several varieties from Ion performance as well.

FWIW, my impressions of a few headers:

Scoobysport - good with hybrid TD04, quite laggy with hybrid VF (which is much better on ported OEM manifold)
HKS - excellent with standard TD04
PE/Maxim - excellent with standard and hybrid TD04, laggy with VF28

From what I have seen, personally I would size the turbo for the application and use ported OEM headers unless you have seen someone else's setup that you really like and you are going to copy it :)

Also some ECUs seem to turn a bit deaf to a lot of transient detonation with some headers. On some cars this could be a disaster.

There seems to be an effect on ignition timing in that you can run more advance with some headers, but the jury is out as to whether this is just due to a slower rate of boost rise.

Headers can make a car feel like it has a turbo one size bigger.

For example, a VF29 car with headers spooled up and flowed very similarly to a VF23 car without and similar spec otherwise. Hence my thinking on just selecting the right size of turbo.

Not enough hard data to give a really clear recommendation for a particular spec of car, and the hope is that it isn't a bit hit and miss and you end up with a lag machine like I did. However the end result I am pleased with and the different (smoother) exhaust note was nice for a while. (but I am now back on ported OEM headers). Don't forget to budget for gaskets - you don't want a leak like I got.

[Edited by john banks - 11/27/2002 8:19:34 PM]

I have read - and it agrees with what John says - that the exhaust headers should be considered as a part of the turbo, rather than being treated as a seperate item. The two do need matching. Some - such as the ones PE sells - are matched very well to the TD04, but are not matched to non-standard turbos so can be a bit pants.
The HKS ones seem to be a very 'well rounded' design & can cope with different turbos well - but so can the oem ones! Well, once they're ported...
I have also heard great things about the MRT headers, but I'm pretty convinced the rest of the car wasn't exactly standard spec :D

Agree with all the above and would just add that to get the best from headers you need to be able to map around them. I've tried ported OE, a local unequal length design (very good high revs, but moved spool point 500rpm up) and finally the PE/Maxim (brought the spool point back down).

I guess it's all down to personal preference - I find the Maxim great (with both vf23 and modified td-05) but others have fitted then removed.

Richard

Richard.

Is the local design you tried from BRT racing??.
Then it´s the same as supersprint is going to sell.

Skassa

We have a whole host of header designs made to maximize specific areas of the power band. There's no "one-size-fits-all" solution when choosing a header & turbo combination.

For those interested, feel free to contact us:

info@ionperformance.com

Skassa,

Yes, it was the BRT one - but I got it straight from the manufacturer :)

iON - yhm!

Richard

Thanks for all the interest. Please note that we're currently in the process of establishing a sole UK distributor, so pricing information will not be released. However, if you have any technical questions about our products, feel free to ask.

We design and make the following products:
(1) Full Exhaust systems (cat-back, turbo-backs) both available in de-cat and catted. *note our turbo-back systems are full 3" and do not mate to any stock components. Our down-pipes are 4.5" bellmouth and merge to 3"*
(2) Headers (N/A and Turbo applications. We have 2 N/A and 5 styles of turbo headers suited to specific applications)
(3) Hybrid turbos (just like the turbo on Harvey's car)
(4) iON Spec OE Turbo Upgrades (upgrades to the OE TD04 turbo)
(5) Full turbo conversions (includes up-pipe, down-pipe and turbo)
(6) De-cat up-pipes
and a whole lot more!

Hello Jack!

I can vouch for your 4-1 header, awesome product (for those that doesn't care about a somewhat later spool).

It really improved middle/top, worked v well with a VF23, and now running strong with a TD MD304.

:)

/J