I'm currently obsessed with the amount of lag my car has so I'm going to try some easy, cheap ways to reduce it.

Current spec:

MY93 WRX
Scoobysport full system from the turbo back
HKS SPF induction kit
Bosch MEC723 coils
ScoobyECU by Scott
Standard TD05 running at 15.5psi (1.07 bar)

Current boost levels: (all recorded in 4th gear, from 2000rpm on a closed throttle)

2500 - 0.3 bar
3000 - 0.5 bar
3500 - 0.75 bar
3800 - 1 bar
4200 - 1.1 bar
4400 - 1.07 bar held to redline

I'm now going to change from the standard boost solenoid to the Turbosmart MBC I was using previously.

 

Easy cheap ways.. hmm

Enable Antilag in the ecu.

Dawes or similar.

Smaller Turbo.

TD05 FE

A proper Map to really get it moving

Ported Headers.

Ported OEM up pipe or cheap up pipe.

David

 

The plan is:

Phase 1:
MBC (Turbosmart)
check the dump valve isn't leaking
check wastegate is working properly and spring preload is reasonable

Phase 2:
ported headers and uppipe (cheap, but not that easy)
exhaust wrap

Phase 3:
Getting beyond cheap and easy...

 

Take the Gold wheels off, that would give you at least 40 BHP.LOL.

I like the way you go about things Dave,cheap will always get my attention,keep us informed.

Zippy

 

Hmm, I have seen 1.1 bar by 3200 on a car I fitted an ECU board to, standard inlet and headers, decat exhaust, otherwise nothing special

Paul

 

Paul, thats what worries me, I've seen comments from others along the same lines. 3800rpm for 1 bar seems awfully high. Problem is, the car wasn't standard when I bought it, it came with a bleed valve so the piping had already been "interfered with" so I'm not sure whats standard and what isn't.

Zippy, cheap and cheerful mate, I'm tighter than a ducks ****.

A quick question, this could sound dumb

Should I be able to move the wastegate by hand, by moving the arm, relatively easily? Mine won't budge with "reasonable" force. Haven't tried unreasonable force yet.

 

That is normal. about 8psi on a 2sq inch diaphragm would be 16pounds of force, which is a fair bit to just start moving it.

Paul

 

notoriousRev...

mail me.

 

David, YHM

 

OK, fitted and adjusted the Turbosmart MBC and the improvement is massive:

2500 - 0.3 bar
3000 - 0.55 bar
3200 - 1 bar
3500 - 1.07 bar held to redline

I'd had the MBC fitted previously and it had always felt fine, but recently I'd begun to notice the lag, which is when I reverted to the OEM boost solenoid.

The car now feels a lot faster and a lot torquier, which is great, in fact it feels better than it's ever done (placebo effect?) I had stripped and cleaned the MBC before refitting and used new vacuum tubing, which may have helped a little.

The wastegate actuator seems fine, and the OEM dump valve definately isn't leaking, so I guess it's onto the harder, more expensive things to try (ported headers/uppipe). I don't suppose anyone is doing these on an exchange basis, are they?

 

I believe David Wallis will do exchange on ported headers, guess up pipe too!

 

When would you like some

David

[Edited by David_Wallis - 11/21/2003 11:25:14 AM]

 

Mail me with a price and we'll talk

 

you could allways try nos,fit system as normal rig to wot switch and through pressure switch in manifold to cut at about 10psi,instant boost from tickover! is easy on nos too as wont take long to spin up.

 

Yeah fantastic if you have lots of spare Subaru gearboxes laying around and clutches....

Jon.

 

what is "the Turbosmart MBC", not something I've come across before?

 

Jeez, who resurrected this?

NOS would work, but I really can't be bothered, I quite like to the way it runs with the Turbosmart MBC fitted (which is basically a purple anodised Dawes device )

In fact, on all the ice that was around on the local untreated roads at 6am this morning, it spolled up a bit too quick

 

Not me mate!

Evenin' Dave!

Which of the above mods / suggestions did you eventually do?
Exchange ported ( and wrapped ) headers are common now about £100 exchange ( Harvey, Jim Litten etc ).

Merry xmas!

 

Whats the difference then between the Dawes and the Turbosmart ?? just the colour??

Im hitting full boost at 3000 rpm (i think) will check tomorrow

 

Doesn't a Top Mount Intercooler give fairly good results bar from heatsoak

a FMIC will give better result's during 'Medium & High' speeds but due to lenth of Inlet and Exhaust pipework Lag is also increased

Wouln't it be better to reposistion the Turbo towards the front of engine reverse both inlet and Exhaust manifolds and fit a FMIC this would drasticaly reduce the lenth's pipework and 'Lag' yet increasing the effieciency of induction cooling

Tony

IMHO

Tony

 

Now there's an interesting thought, major pipe work job!
911

 

duplicate

 

you would need to remove the radiator.. and make some special headers.. funnily enough I have some exhaust flanges in the garage for just this..

David

 

Would it realy give an advantage? Be a great thing to do if you had a bit of time.
It did make me think about another thing though while I'm pratting about bolting all the goodies on...911

 

You could try tightening the actuator rod a little to take up any slack.

My MY 95 UK saloon hits 1bar at 2850 rpm and 1.25bar at 3100ish.

Std TD05
K&N Panel filter
Revolution 3" decat DP and system
MAF de-grilled
MRT inlet plenum pipe
Walbro and FSE reg
Apexi PFC

 

The NOS idea is ok if used from 2500rpm on WOT then kicked out by a pressure switch as mentioned to blend NOS/Boost. Still not got mine fitted yet, but its in the pipeline. 15 shot is enough for this.