im going in at 472 bhp

good luck

478 this time

420-450 on this turbo depending on the supporting mods.
The main thing though regardless of power is to get it right so you have the confidence in driving it to Belgium and back.

amen to that brother - adam started things badly last year when he caught his exhaust on a speed bump at 6.30am in ashford

469,and thats not an educated guess

Lucky you even got there.Mine spun the shells a week prior to going there.

jeez you've had one hell of a year with that car mate

i was fine till i shook your hand and took on the curse of Proccy

6,500 bhp

Well as Adam said, it was all going very nicely until the fourth run where the turbo decided to "unbalance" itself. The previous three runs were just setting a base for the various boost levels, so there was quite a bit of power and torque left on the table.

0.9bar
341bhp @ 7364rpm
257lbs/ft @ 6383rpm
277wheel power @ 7077rpm

1.3bar
372bhp @ 7076rpm
318lbs/ft @ 5627rpm
322wheel power @ 6350rpm

1.65bar
383bhp @ 6436rpm
344lbs/ft @ 5267rpm
340wheel power @ 6156rpm




My experience tells me that we would have seen 400bhp & 360lbs/ft after final tuning. The powerband is excellent with over 370bhp from 5750rpm to 7500rpm. Given that Taffy has standard cams and we are only using 97 octane, it does show how efficient the setup is as 383bhp was made with only 1.2bar towards the redline!

Of course the new GT3071R 0.86 is a quite a different proposition... I know what I think it will make, but I won't spoil the fun and games

I believe that should say 344 lbs/ft @ 5267 rpm.

Question, Flea. I am surprised that the boost curve on runs 2 & 3 is not flatter - the turbo would seem capable of sustaining the 1.3 bar peak in run 2 and the 1.65 bar peak in run 3 much further up the rev range before tailing off. What is your boost control strategy?

Last thing - do you record, and therefore can you graph, charge temperatures?

GT30 required
Just get a good supply or diffs ready.

It should indeed!




This is the second GT2871R 48trim (0.64) that I have tuned in as many weeks, and they both hold boost in a similar fashion. In both cases they have rather weak actuators i.e. 0.6-0.7bar preload, so as the rpms climb there is a greater limitation to how much boost can be held. That said, the turbo is capable of holding more boost with the right setup, but the efficiency is marginal at this level.

Boost control is via an Apexi AVC-R, still the best available after all these years!



Not logged, but they were in the high 30s - low 40s.

469bhp

what the hell!

Ah, thanks for the explanation.

I had assumed you were able get at and re-map the standard ECU to set boost versus RPM. Is there really no better boost controller available that can use RPM and MAP (maybe from an internal MAP sensor) to give better control?

Secondary question - how usefull is the Apexi Ne-Points feature and how exactly does it work?

Yes I can do. There are many of my cars using ECU boost control, some running up to 1.7bar. However, while this has many benefits, the obvious drawback is a single boost profile. For this reason, many choose to go with an external controller so that multiple boost levels can be used to "suit the moment" as it were.



The Apexi is not only good at controlling boost in general, it also offers gear specific control as well as rpm based control i.e. NE points. The former is generally most useful, however where the situation dictates the NE points control is also very valuable.

taff whos headwork is it?

Pretty sure it was done by Barbz originaly, Paul at Motormech has done a few more bits to it also.

Good luck, I reckon around 465bhp and around 395lb torque

472 bhp for me.

Any updates on this?

Long story.

I bought the 3071 .86 off JBT but John had some problems getting hold of the turbo he needed to replace this one. So, I bought a 3071 .64 from TurboDynamics and had Leighton fit it. I thought it would have a bit of boost creep (all the GT turbo's creep on my car, not sure why ) anyway it's was creeping to 1.7+ bar with the apexi switched off .

The next step is to port the exhaust housing and try again.

1.7bar!!!!

What the hell is causing that????

Hope you get it sorted!!!
It's in the best hand with Dr Flea

Somethings not right there. You shouldn't have 1.7Bar with the APEXI off. What rating actuator spring do you have? Is the arm getting stuck? Is it adjusted correctly? Porting the penny valve may help but you should find the route cause of the problem.

Is there a specific reason why every run is Inertia?

GT3071 have always caused boost creep (on 20vt's anyway), way back when Fergie put this turbo on the car. It's a case of not enough gas flowing through the internal wastegate causing the boost to rise. I have the same problem on my GT3076 and this was after enlarging the external wastegate to 44mm from the 38mm

I think when the 30 series first became availible with internal gate they used the smaller gt28 back housing, reprofiled to suit the bigger turbine. I don't know wether it's still done that way or not.

Whats going on mate? Any joy?

It's done but still has slight boost issues from what Leighton said on the phone. I will speak to him in person tomorrow and get the info.

It made 432bhp