Hi guys,

Looking for some experience here if possible. I have a MY99 UK Turbo running Japspeed tubular headers and up-pipe, sports cat downpipe, decat centre and 4" backbox and after reading a few threads on here I think the headers and up-pipe are proving detrimental to the turbo's spooling capabilities. The top end is fantastic and it pulls really well to the redline, but i'm looking for a bit more response.

Would it be advisable to swap back to original headers and up-pipe? I don't want to go too much further with the power at this time, that'll come later with a full re-build, so would standard headers support 320-330bhp sufficiently?

Thanks in advance,

Dan

 

yes standard headers will be fine for what you want,a vf28 should not be laggy at all.

 

tubular headers are really only any good if going in excess of 400bhp, any lower and they can have an adverse effect on the spool, espically ebay jobbies
Id personally recommend Harveys ported headers and up pipe , u will notice a massive diff

 

Great, thanks for the feedback guys, I thought as much. Harvey's headers are certainly on my list, so i'll swap out these Japspeed tubular headers for a set of them.

Am I correct in thinking i'll need a remap once I change the headers?

 

Does harvey port the factory headers and upipe? Curious to know how it done

 

You wont go wrong if you buy a set off Harvey's headers he is strongly reccommended by many on this site and on other subaru sites as well.
My Uk car has std headers with a vf28, and boost starts coming in at 2700/2800 rpm and comes alive once your at 3500 rpm & is currently running 330 bhp.If you decide to get a set off harvey you will need a tweak to your existing map,as the vf 28 is one of the quickest spooling turbo's n the vf range.

 

Cheers Midnight, that'll give me a chance to get the 3 port boost solenoid fitted and mapped in too as i'm still on the two port at the moment.

Many thanks guys,

Dan

 

I take it you've uprated the fuel pump ,if not get that done as well

 

Sorry dan , i read your other post on another thread ,so i take it you have.

 

No worries mate, the car is running reliably, i'm just looking to improve on it now. I think I might move across to Simtek in the future as I like the idea of being MAFless, don't like the idea of that failing and lunching the engine!

I have to admit though, the VF28 is a fantastic turbo for a road car. the midrange is excellent, even if i'm not making the most out of it at the moment!

 

I did think about a simtek ,but at the momment ,I have had a MY99 car and at current a MY00 car and not had a maf fail on either car.In fact i bought this a few days ago as i know my current maf is sound :

http://www.ebay.co.uk/itm/3006041873...84.m1497.l2649

I cleaned the mesh and the sensor with brake cleaner ,then fitted it to my car yesterday.Reset the ecu and took it for a drive ,no fault codes and car runs perfect,so i have my current one as a spare. I know they can fail,but are more prone to fail when used with an induction kit opposed to the std airbox which allows a smoother flow of air across the sensor.

 

That's exactly what i've done . That way i've got one at hand should anything happene, can't be too safe!

I'm running a Simota (dry) panel filter and wouldn't want to go to an Induction Kit anyway as I find the noise a little intrusive to be honest so i'm keeping my fingers crossed that these two MAf's should last me a good while. Even if i went Simtek, i'd want to keep the standard airbox.

Dan

 

The OE Subaru headers will be a big improvement on what you have now.
Properly ported headers with matched uppipe will be an improvement over the OE.
If your car was remapped for the tubular you need a remap to go back to OE or ported. If it was not mapped then you should be OK.

The correct choice of headers and uppipe will vary depending on the turbo and spec but getting the selection wrong can be a very disappointing experience as I think you have found.


As an aside you will get quicker accelleration from your car changing up before the red line than holding it to the red line.