hi,

I wonder if any of you can help. I just fitted a set of Eqaul Length Headers to my Impreza (previoius mods, sports cat, exhaust, VF35 Turbo, Sti 8 Intercooler, and remap circa 305BHP) and now my car has major turbo lag since the manifold.

The Headers I bought were quite expensive (£500) and before I ordered them I made it clear that I did not want to increase turbo lag.

I understand that a lot of "performance headers" increase turbo spool up time due to wider primary pipes reducing gas speeds in to the turbo. But I bought these as I was told they would slightly reduce turbo spool up due to there equal length design.


Before I panic too much can anyone say whether a remap will help reduce the turbo lag again? If it wont they will have to come off! My car used to boost up nicely by just under 3000RPM and now nothing happens til 4000RPM.

Oh and the manifold was fully heat wrapped first.

Any help appriciated!

 

I should also say that they are 4-2-1 design. Any ideas re the increased turbo will remap help? thanks

 

What make are the headers ? Any pics ? Not all 4-2-1 headers are created equally, some work much better than others......

 

Will a re-map help? Almost certainly, probably very significantly.

Will it give you spool up as good or better than you had before? Without more information and experience of the specific headers in queston it's impossible to say; however from seeing what some others have achieved, I'd think it is most likely your spool up/lag will probably be a bit worse than before

 

Most tubular headers result in reduced spool and this is quite widely known. This is a trade off against more ultimate top end power over the O/E headers.
For a quick cross country car or to be quick off the mark you need quick spool and low down torque and these are not characteristics normally enhanced with tubular headers.

 

They are X -Force ones.

Welcom to XFORCE (Muffler and Exhaust System)Home Page is the manufactuers website but I bought them from a well known Uk based Tuning Specialist.

 

Interesting one this, I had a call from someone Friday who had been told by a 'specialist' to replace the OE headers with aftermarket headers to "improve the spool of their turbo".

Not something I'd suggest in isolation.

 

Is this true for aftermarket un-equal length headers?

 

Many designs truely equal length headers can improve spool over the stock setup, but from the few dyno results I've seen many of these designs offer no improvement in top end power.

 

Consider gas flowed ported O/E headers which will show marked improvements across the rev range.

 

considering getting getting h&s equal length headers

Any comments on these?

 

Most un-equal and some equal length headers are a 4 into 1 design, and typically they cost a few hundred RPM in spoolup but give a fatter torque curve once on boost.

 

hi, does anyone else have any experience of these headers? Any more ideas if remap will help? thanks

 

I have a set of these x force headers fitted to my 05 WRX and can honestly say that i noticed that that the vf35 turbo that i have spools up quicker now then it did with the OE headers. These headers are superb they also decat the turbo up-pipe as it all one piece. The only thing i will say is that the stainless strips that join the headers together break over time and the headers can come apart( very loud and disconcerting when it happens) i replaced them with handbrake shoe springs and touchwood they have done the trick.

 

Hi, thanks for the reply, did you notice an improvement with spool straight away or only after the remap? My car is a classic so does not have a cat in the up pipe, but it does have a VF35 turbo. I wonder why my car is slower with the headers then before below 4000RPM when you notice an improvemnt in spool up time. I suppose removing the cat helped you a bit.

 

Decat up-pipe with standard headers would also make a noticable improvement to spool up.

That's not to say the x force headers aren't good, just that you effectively changed two things at once (headers and up-pipe) making it a bit harder to define which bit made the difference.

However, the key point here to the original poster is that someone has tried these headers with your turbo and got very good results, so you should be able to get similar too, once the map is sorted.

 

Good Point Hades my now puts down 320 bhp and 405nm torque and i haven't gone overboard with the boost 1.25 bar as it is a WRX and i didn't want to overdo the boost. I had my car mapped at powerstation and i know they have achieved 350bhp with vf35 by cranking the boost higher on STI's. Sounds like the car may be running lean at the bottom end now that with the new headers and turbo are flowing so much more air hense the percieved slower spool up. Consequently i wouldn't be hammering the loud pedal too much at the moment wait to get her mapped up.

 

if this is the powerstation manifold i had good results will little loss of response if any

untill they popped managed about 15k miles

 

I am using headers from Tracktive. GT Spec 2 replicas, they have them made apparently. With Richard's knowledge about different headers and the fact some of them dont even do anything and can lose you peak torque, i am confident in them for sure.
No flexy joints as they fail. Like many ppl say, steel is not flexible!
3 bolt flanges on the up pipe, etc, etc.
So very good quality i hope and backed by experience.

 

The best equal length designs copy the JDM factory setup of the JDM STi twin scroll cars. These also need a twin scroll sump pan to be fitted. Piping has a shorter run than those shown in the link above as well and these can help spool.

 

If that's true, it makes you wonder why subaru put 2 flexi joints in the stock manifold system.

Steel like every other material is flexible, your suspension rather relies on it!

However many flex joints in aftermarket parts are not up to the temperatures involved, and will fatigue after time and heat.

Paul

 

^^^^ cool, must get some

F

 

Gareth,

The OE ported items are extremely good and should work well if used with a custom up-pipe from the same guy who does the porting. Unfortunately he cant advertise here, can you Harvey.

 

who make these copies and where can you get them from?

 

I have just purchsed this manifold and turbo down pipe for my Sti 5 which is currently having a new engine installed, with a new VF34 turbo. Does anyone have any experience with these manifolds, they are un-equal length but the finish is of a very high standard and Tomei has an excellent reputation in Japan...........

http://www.tomei-p.co.jp/inf/pdf/60_ae.pdf

 

Perrin and APS make them....the APS is almost identical to the factory item, but with uppipe for std fitment turbo. Available from the States.

The Perrin EL header will work with your existing uppipe.
Both need the Twin scroll sump pan.

Fujitsubo do a high quality equal length header too....fits with std uppipe and std sump pan.....nice short runs as well......not sure where to get this from over here.