im currently in the market for some headers and a uppipe for a 95 wrx.. basicly ive spoken to harvey a few times and was considering havin the oe header ported and wrapped and a uppipe supplyed by him but am findin it hard to raise to £'S to do it his way.. if i had money then i would go with harvey but atm i just dont have the cash and as i look around for alternative solutions im finding various aftermarket headers around either on SN or ebay ect at prices that seem alot cheeper.. so basicly need advice on which header and uppipe people think best ..

 

Harvey's. No contest.

DO NOT buy cheaper, you will just end up dissatisfied and wanting to sell them on. Waste of money. Get the best from the start. Save up if necessary.

 

Depending on your mods you may well be better off with the ported and wrapped headers and up pipe such as Harveys.

The reason I say this is that the ported OEM header has a smaller overall internal volume which has the effect of speeding up the gasflow to the turbo, with a tubular header the internal volume is much larger which allows the engine to breath easier but it reduces the speed of the exhaust gas to the turbo which in turn causes a slower turbo spool.

I have found so far that for example on a UK car with a FMIC, VF turbo, 550cc injectors etc will perform better overall with a set of ported OEM headers due to the better turbo spool and the header seems to cause no real restriction top end, however on an Sti which has higher flowing heads may benefit at the top end with the tubular header, this benefit would be more pronounced when running a larger turbo.

I think overall the heads and turbo used would determine what header setup you should use but I do believe the OEM ported header from Harvey would be the correct choice.

Cheers Iain

 

As BigD says, turbo choice has a lot to do with choice of headers, as does what power you want.

Harvey is the man to speak to.

 

Trust me fella you'd be better off with either harvey's headers, or proper HKS ones (circa £900 ), which makes harvey's sound like the cheap option!!

I made the mistake of getting the cheap ebay ones and i was absolutely gutted... They're tinny, fit horrible and after a few miles they go blue so they don't even look any good!!!

If i could go back and do it again i'd have bought harvey's all day long

 

Not everything cheap is good,i recommend headers and upipe from Harvey.
Or look elsewhere for GTSPEC headers which are little bit pricey,but are good.

 

as i said i have spoken to harvey a few times he has explained to me about the porting of the oe headers i do see this as the best option.. i think im just getting impationt and need to hold myself back abit longer so i can get harveys uppipe and header .... dam i hate having to wait !! lol ....

 

Save your money up and go with Harvey - tbh on a pretty standard '95 WRX, the headers and up-pipe from Harvey would be a wise purchase.

Mick

 

What spec are you going for? Porting them DIY will cost you very little if you are on a budget. GT Spec headers are worthwhile on anything from mid 300s onwards.

Don't bother with unproven cheaper ebay type headers.

 

There is a lot more to porting than just getting a dremel and increasing diameter. In addition, each joint is an opportunity to improve gas velocity. Only with considerable experience and the use of flow bench equipment on a number of occasions have we been able to perfect our porting. Equally important is the uppipe and design so all our header sets go out with a purpose designed uppipe taking in to account the turbo in use and engine spec. There are six uppipes in my 2 bolt range allowing us to match accurately the client requirement.
The GT header set is intended for big power operation. Unfortunately by virtue of the design the spool is slugged badly. For that reason I have a special 3 bolt uppipe which is quite innovative and everyone that has fitted it has been impressed with the improved spool without any loss of top end. There are 2 special 3 bolt uppipes because again one design will not do everything and all uppipes are slip jointed which means there are no gasket issues which is one of the problems with the GT Spec header sets in the first place.
Fitting GT Spec headers on a 350 bhp car for normal road use would be a big step backwards in terms of driveability and spool. Many people have found this to their cost.

 

Have you got any gains on the 2.5 Hawkeye?