Please Help Me With My Very Lazy Gt2860-9's!

[Tai1or Made]

Drop the cat and drive?

[tommis85]

Drop the cat and drive?

That would be the plan

[tommis85]

Although because my Cat does't have a flange plate at each end I'm gonna have to drop a whole chunk of the exhaust and run it off the dumps That RB melody hehe

[Tai1or Made]

Film results.

[tommis85]

Haha I've fired it up a couple times off the dumps while doing turbo swaps....it is quite deafening in the shed

[r32-25t]

I'd be getting rid of the dumps, cause I had the same dumps and the same issue. Since changed over to Midori dumps (but changed to -5s as well)

[tommis85]

I'd be getting rid of the dumps, cause I had the same dumps and the same issue. Since changed over to Midori dumps (but changed to -5s as well)

Oh I see....well that's the thing - I've been reading about peeps who swear by them and then others who're fans of the bell mouth style ones which are what you're using (I think).

So did you have a set of -9's before you went to the -5's? Keen to hear more about these xforce dumps and why they're not that good...I'd be happy to swap them over or even put my stock R33 GTR ones back on (I know people make decent figures on these too and also use them as upgrades on the R32's)

[MrStabby]

I use xforce split dumps - they're fine. 305kw @ 17psi on -7s. 16psi at 4000rpm. If anything you could go slightly backwards spool wise with a bellmouth as they produce more turbulence post turbine. Changing dumps is turbo out, so not only will it not help, it will be expensive for labour....

[tommis85]

Ah ok - that's the divided opinions right there haha

Ah the swap isn't too bad - I've gotten it down to about 1 day's solid work now but don't really want to do it again! Those are some nice figures by the way - you must have an excellent tune! Yeh at this stage I'm just going to drop the cat and cat-back out to see if there's any difference. If there is, it's new cat and new tune time ;-)

[levinboy]

I have -9s with HPI bellmouth dumps one of the biggest on sale. Running 330awkw 18psi full boost 3800rpm.

I don't think your dumps are the main issue, yes could improve with different ones, but as stated before drop the cat and check/replace it.

I had an issue with a previous "hi flow" cat that was causing a 10+psi restriction

[tommis85]

I have -9s with HPI bellmouth dumps one of the biggest on sale. Running 330awkw 18psi full boost 3800rpm.

I don't think your dumps are the main issue, yes could improve with different ones, but as stated before drop the cat and check/replace it.

I had an issue with a previous "hi flow" cat that was causing a 10+psi restriction

Wow those are even more awesome figures! Ok, well tomorrow I'll drop the exhaust and see what she's like and post it up on here. Yeh 10psi+ seems like a massive restriction - I'd probably have something like this too.

But yes, we shall find out tomorrow.

Thanks for all your replies so far - most helpful in a time of great frustration!

[R.3.2.G.T.R]

i have 18psi by 3800rpm on hks dumps so problems for you there, also had an issue with blocked cat previously and car lost 40kw, check for leaks as well

[tommis85]

i have 18psi by 3800rpm on hks dumps so problems for you there, also had an issue with blocked cat previously and car lost 40kw, check for leaks as well

I'm assuming you mean "no" problems there...are you referring to the split dumps? 40kw hey? Yeh I need to gain at least that much....really hoping to make close to 300kw to make all the money spent worth while!

[Manuel Kasko]

Also guessing you already know but don't flog the shit out of it with the cat dropped.

It's not going to be tuned for the extra flow and power so might lean out at some points

[tommis85]

Also guessing you already know but don't flog the shit out of it with the cat dropped.

It's not going to be tuned for the extra flow and power so might lean out at some points

Haha offcourse not. I've been talking to the tuner about this...about how much margin there would be for this. I basically plan on just giving it a gentle tap because I'll know right away if it's had an effect - that's how poor it's performance is right now. Then I'll be booking it in with the local exhaust mob to get a proper hi flowing cat put in place, along with a larger internal dia canon

[Manuel Kasko]

You would not normally expect a tuner to do this when he notices a problem or did he just think you put a lazy turbo on it?

[tommis85]

Yeh tuner didn't know much about my turbos...didn't even know -9's existed in the 2860 range Mainly does bigger turbos and singles.

She's obviously gonna need a re-tune once exhaust has been rectified (provided that's the only problem and it's not something more sinister etc etc)

[Manuel Kasko]

Fingers crossed mate.

Is the tuner going to hit you up with a free touch up tune?

[AngryRB]

just curious, if the tuner dropped the exhaust on the dyno how would the gases get collected, from what i seen the fans or whatever that suck them up and deal with them are right at the back of the dyno room, so wouldnt that fill the room up with fumes???

[Manuel Kasko]

It's better to be high and not drunk