Getting Rid Of That Flat Spot!

[moobaque]

Hey all,

My r33 gtst is putting out about 210kw with a selection of basic bolt on goodies. My goal isn't to make big numbers but I do want usable power. So having said that here is my issue.

As it seems at the moment 1st pulls quite well but shifting up into any gear even from redline has some serious lag. I don't appear to get any power back for 2-3 seconds in the next gear but then it kicks. This doesn't feel like a fuel supply issue nor does it miss or splutter (but i will be putting something like a 040 in soon anyway). (injectors are getting high on there duty cycle but certainly not maxing). Spark plugs are also new gapped at .8 (coppers)

So this is what the car has.

3" inch turbo back stainless steal exhaust with hiflow cat

apexi pod filter

turbo smart bleed valve (peaking at 12psi)

blitz front mount (this is no doubt not helping the lag issue at my current power)

apexi powerfc (tuned by re customs)

adjustable exhaust gear (currently at 0 degrees)

I'm assuming having just a bleed valve it may be allowing the wastegate to be opening early. But would it be that bad that an ebc would make all the difference? i don't know but i am assuming not.

I will also be looking at getting the standard turbo hi flowed mainly so the 13yo turbo doesn't disintegrate into my engine...but will the hi flow allow a faster spool up or should I be looking to spend more cash on gt-rs or similar? (a bolt on option is much more preferable than having to get custom piping / manifold made)

The car hasn't been tuned since we did the 100,000k service to it (and this is when the adjustable cam gear went on) So not sure if much if any benefit will come out of that at this stage.

anyway just looking for suggestions on what road i should be going down. I don't have a large wallet and i reiterate im not after big power figures just for the power to come on more linear.

Cheers

Camden

[lachlanw]

is your blow off valve set up and working properly. and also is the injector time delay set up properly ? cant remember propper word for it but it is why subarus feel laggy when you put a front mount on them . maf sees more air so puts in more fuel . extra air hasnt reached motor yet but xtra fuel has so rich flat spot then clears .

what is your boost gauge doing right after a shift ?

[moobaque]

is your blow off valve set up and working properly. and also is the injector time delay set up properly ? cant remember propper word for it but it is why subarus feel laggy when you put a front mount on them . maf sees more air so puts in more fuel . extra air hasnt reached motor yet but xtra fuel has so rich flat spot then clears .

what is your boost gauge doing right after a shift ?

The blow off valve is standard and plumped back as it should be (and appears to be functioning correctly)

As for injector delay I am not sure but would be hoping this should be looked after correctly by my tuner (of whom i trust) although the car does run quite rich as demonstrated all over my rear bar.

I cant tell you exactly about how the boost gauge responds atm as im out of town (back home in a week) but from memory on shift and peddle down it jumps straight back up to something just over 0... maybe about 5psi!? sits there for that few seconds then builds its way to 12 relatively quickly. (like i said will be able to explain better next week when get home and give it a drive)

Cheers

Camden

[_Ryan_]

not going to doubt Ray as i know they do great work, but maybe talk to him about retarding the exhaust cam gear 2degrees(suggesting from other threads i have read, it is meant to help response) and pre boost timing, might be able to run more?

[DRD-00F]

I've never heard lag and standard turbo said in the same post...

If the bov is working properly, then maybe you have an ignition problem...

Another thing, that has happened in the past, is the adjustable cam gear on tight?

[moobaque]

If the bov is working properly, then maybe you have an ignition problem...

There is no obvious missing and when i changed the plugs and at that time i looked to see if there was any arching happening with the coil packs before putting the garnish back on and everything seems alright.

Another thing, that has happened in the past, is the adjustable cam gear on tight?

cam gear is torque to what was specified on the paperwork but its not something that happened after putting it on anyway... was like this before.

Cheers

Camden

[moobaque]

not going to doubt Ray as i know they do great work, but maybe talk to him about retarding the exhaust cam gear 2degrees(suggesting from other threads i have read, it is meant to help response) and pre boost timing, might be able to run more?

Yeah I'll definitely talk to Ray about it when i get back to Melb and get him to do a bit of a retune. Maybe go down the ebc path to at the same time and see what he can do with it.

This really has been something that the car has been doing for a long time but was less obvious up until recently as my clutch was progressively dieing. I now have a much more serious clutch (certainly no slippage anymore).

Cheers

Camden

[Munkyb0y]

its possibly your boost controller. if it doesnt allow the wastegate to close quickly enough, this will happen.

i had a similar thing happening with my turbotech mbc. then i drilled a hole into it to let the pressure out of the actuator line immediately, and it made a huge difference.

theres always going to be the split second re-spool at gear changes. but 2 or 3 seconds is too long.

[MBS206]

Turbo smart bleed valve has a TPiece in it correct?

If it does, openit, remove the ball and spring, put it back together. (WITHOUT THE BALL AND SPRING)

This thing holds the waste gate open.

Had the same Boost Controller, had the EXACT same issue.

[moobaque]

Turbo smart bleed valve has a TPiece in it correct?

If it does, openit, remove the ball and spring, put it back together. (WITHOUT THE BALL AND SPRING)

This thing holds the waste gate open.

Had the same Boost Controller, had the EXACT same issue.

Certainly worth trying! I never thought of removing it as i was under the impression you only removed it if your boost was spiking.

Cheers

Camden

[MBS206]

Certainly worth trying! I never thought of removing it as i was under the impression you only removed it if your boost was spiking.

Cheers

Camden

Typically you remove the whole boost controller as it is a bastard piece of shit really. (Although mine is still bolted to the firewall, it really is crap, and is disconnected)

[moobaque]

Typically you remove the whole boost controller as it is a bastard piece of shit really. (Although mine is still bolted to the firewall, it really is crap, and is disconnected)

Your post doesn't really make any sense... Are you just trying to make the point that an ebc is better than a bleed valve (clearly this is true so not very helpful)

Or do you think we are talking about the stock boost solenoid?!? the stock solenoid is redundant with the bleed valve or an ebc for that matter and is bypassed...

Cheers

Camden

[mad082]

i had a worse version of this issue when i had a turbosmart dual stage controller. i would change gear and not get any boost until i lifted off again for a little bit. first time i changed into 3rd with the controller on i was at about 4000rpm (had just changed from 2nd at high rpm) and had zero boost with WOT.