Twigster

Have a question for all the knowledgeable crew...
I currently have a funn H+S de-cat, ITG filter (temporary measure until the k+n panel arrives) and a John Banks Tek2.5 ecu.
Last rolling road was 266bhp and 244lb/ft torque, but that was without the tek!
Question is, what is my next step regarding mods to help me get my torque figure up around the 300 mark? I am hoping for around 260 with the tek fitted. I am aware of hybrid turbos etc, but am happy with the lack of lag that the td04 gives and don't want peak power at the sacrifice of drivability. So what is the next step?
I await your replies!!

Twigster

No-one have any ideas?

greasemonkey

TD04 stops you going much beyond where you are now, so turbo change pretty much unavoidable.

If you want to keep as much of the response as possible, try VF34/35, or maybe the angle I'm itching to explore - twin-scroll VF36/37.

Twigster

I understand it may eventually be avoidable, but for now I am looking at the 'relatively' inexpensive stuff such as fuel pumps/regulators etc.

nom

The only option that I can think of would be changing the manifold - it would require a remap to get the best out of, though.
And, if you're a tart, the noise would change if you were to pick a manifold that was suitable - the JUN (? I think!) equal-length jobbie is very well suited to the TD04. More power possible & the spool-point either the same or lowered (I can't remember which ).

greasemonkey

The likes of JB would know a lot more about this than me, but I don't think you'll get any appreciable gains from changing the pump and reg until after you've changed the turbo.

I don't think the standard pump, reg and injectors would be troubled by a TD04L. It's only when you go to a bigger turbo that the need for greater fuel flow rates really becomes apparent.

Bob Rawle

You won't normally get any gains just by changing pump and injectors unless you remap to suit. The injector duties will remain the same unless you do.

bob

nom

Basically, you want to address the 'weak point', and the weak point is airflow (not fuel flow!). The airflow is currently restricted by the turbo, but you can 'help it along' by freeing up the exhaust system to allow a better pressure differential between the in & out side so the turbo needs to do less work (done with the DP, etc.) but also increasing this with the manifold (the VE will improve with this too).
A better intercooler can effectively improve the fuel flow as well - either by reduce inlet temps (so denser charge) or offering a lower pressure drop, so the turbo has to work less for the same pressure at the manifold, so a higher boost becomes available.
A fuel pump is a good idea but won't produce any more power at this level, it just might improve the 'solidity' of the fuel flow... a regulator only really becomes necessary if you need to push the 440s beyond what they are capable of at standard pressure (short bursts at 350bhp are just ok for the standard system ). And you're not going to get anywhere near that with the TD04!

Twigster Home

Hmmm. So the turbo has to ge really before I can do anything else.
Is there much point in fitting an Sti 5/6 intercooler as opposed to the standard uk one? Or is it better to just stump up and fita FMIC?
Also, if I was to change the turbo ,what would be a good one to go for? I have heard that the VF28 is a popular choice but I am concerned about the amount of lag that would generate. I was thinking of possibly a TD05 or similar. Any suggestions on pro's/con's of each?

greasemonkey

Given your target output, an STi 7/8/9 I/C would probably be the most practical option for you. Bigger core than the STi 5/6 part, but without the extra expense and complexity of a front-mount.