Guess the bhp...

My car is off to Leighton on Saturday for mapping
I planned to get the car to this stage before Spa last year, as you can see things didn't quite go to plan

Full spec of the car is here TorqueStats

The prize is a signed photograph of PininPrestatyn (very rare) and also something worth having, if I can find anything

377.4

Sounds like it'll be.... Phenomenal!!!!!!!

377.5

Is that with a 48 trim compressor, a 52 trim compressor or a 56 trim compressor?

A big difference in the power potentials according to the compressor maps....

That's a VERY similar list of mods to my own - the only obvious difference is C&B cams and injectors (I assume you're going for bigger injectors)

I reckon Leighton will break 400 with that setup, especially if you're brave with the boost

my guess - 420bhp @ 1.6 bar

Oh - hang on - just seen the prize for getting it right...

My new guess is 100bhp

It's a 48 trim compressor

Nigel - Yes bigger injectors will be going in. I'd imagine 440's ? and a big MAF.

398 BHP @ 1.5 BAR, 348 lb/ft of torque.

421bhp

422 Bhp

Exactly the same turbo as mine then.

I really don't know whether C&B cams give much additional peak power - I'm assuming they give more in the mid-range, although the small extra lift will always be helpful at the top end.

Have you decided the maximum boost you're going to let Leighton run? (mine was mapped to 1.7 bar, but this only gave 7bhp more than at 1.5 bar, so I never bother to run the highest boost setting)

I thought long and hard about cams. In the end I decided that nearly 1k (for c&b's) for 10bhp ? wasn't worth it.

Probably 1.6 bar.

Just out of interest Nigel, is your base boost 0.8 ?

When I got the car back from Paul I had major boost creep (I did with the 28rs as well) I can't get mine lower than 1 bar.

Looking at the compressor map, it would seem to be quite efficient at 1.7 bar between 4000rpm and about 5300 rpm, and from there it would need to taper down to about 1.4 bar or less at maximum flow (about 38lbs of air per hour) to avoid a) running over speed and b) running at less than 65% efficiency. Depending on Air Charge Temperatures, 1.7 bar could deliver some impressive peak torque figures. I am looking forward to seeing the results that Taffy's car attains!

Guys when you talk about boost, do you mean mid range boost (=high torque) or top end boost (=high rpm 6000 and above)?

When I did my last RR I had 1.32 bar at 6100 rpm. Hp was 358.

I guess that you get 410 hp.

It varies - Its usually around 0.9 bar, but I can occasionally get nearly 1 bar with the boost controller turned off

On the assumption that you make good power, I reckon that base boost is one of the most impressive things you'll find about your new mapping - its SO smooth and progressive, with no big thumps in the back, but you're still producing over 300bhp and the fuel consumption is notably better - its really a pleasure to drive and its much easier on nervous passengers

I'd be tempted to check your dump valve orientation and operation - I've never suffered from boost creep on any of the turbos I've had

438bhp for me!

Glad it's up and running mate!!!
Looking forward to seeing it!

I'll be mighty impressed to see that from a 48 trim compressor wheel! I think even Garrett only rate it at 385bhp....

I'll go for 391bhp, 348lb/ft....

Can't wait for that picture on my bedroom wall .....

Really looking forward to seeing your car Adam. Any chance of a lap or 2 with you at Spa?
I think it will make an easy 390hp but i would like to see if you run about 1.4 max for a while,just to see how she goes mate.

391..If I win can I have the azevs ?

441

Really???
Oh... Well only reason for that guess is the spec is the same as nigels bar the cams... Nigel managed 457 I think on that turbo!!!

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2871R_743347_1.htm

Another site says 385...

http://www.tialsport.com/prod_tc_gt_28r2.htm

A 56 trim would be capable of more power, though.

Will the bigger trim be more laggy? Or is that in the housing side of stuff?

My guess is 419bhp.

Good luck.

Wow and may I say WHAT a prize Quite the collectors item, and I promise NO Purple jumpers! If I win I want a signed picture of Nigel sitting with the BTCC star Matt Neal in a Coupé, and a toffee crisp*

Anyway, The winning number WILL be 427BHP!


* The picture and the Toffee Crisp are separate. Although I would settle for a picture of Nigel, Matt Neal and a Toffee crisp if not.

I think it all depends on whether a biased dyno is used. I reckon 388bhp on independant, 415bhp at bristol.

Ross

Can a dyno be biased, if it's just a machine? Would generous be a more suitable word? I honestly don't know.

No disrespect to Flea at all, but over the years the difference between a mappers dyno of choice and an independant, has always been noticable. So hence the 2 figures.

Ross

how do you know which one is right, if either of them is? and surely for pure comparison purposes it's best we all use the same equipment.

i guess at 405bhp

400.7 bhp

Yep, it purely depends what dyno is used. If Garratt rates a turbo for 380 odd bhp, how can it possibly do 420bhp or more??

i only ask as a novice not to question anything - but if garrett state 380bhp do they anticipate that topline figure after mapping then? if they rate it without then surely they'll get a load of complaints that it never met that bhp? isn't it a bit like fiat stating the coupe is 225bhp or whatever the 20vt was rated at, then mapping increases that to, say, 258 as it did on my original set up?
just interested, no vested interests here ....

if turbo is rated at 300hp then thats the safe hp for it,the same turbo could do a lot more.

I make 374BHP (Flywheel estimate) on that same turbo at 1.7Bar (48 trim) with a similar spec on a hot day. I would expect a very similar result using the same dyno as me. So my guess is 370BHP-410BHP depending on dyno/atmospherics.

The stated power of the turbo is the peak power within the efficiency graph. If you have extra cooling like good fmic, aquamist etc then you can push it outside the stated bhp.

Ross

I was asking as I didn't know. Interesting to see the figures can vary by that much!

Saying that, Nigel's car was mapped to 457bhp on the same turbo?? I guess the official figures are very conservative then!

I have a feeling that my 457bhp was a little on the optimistic side, but I'm not too bothered. The beauty about all of the Flea-mapped cars is that they are nearly all run on the same dyno, so the power is measurable in relation to other cars (albeit on different days)

I might speak with Turbo Dynamics and ask them about their expected figures. I seem to recall that the expected power was based on a certain flow rate of the turbo keeping within a pre-determined efficiency rating.

Are your dyno results posted anywhere on the forum, so I can take a peek?

Thanks.

Its interesting to see that on the Run1 and Run2 traces (blue and red) power was still climbing at the end of the graph - this was 1.0 and 1.2 bar respectively

403.8bhp

421bhp

428 bhp & 368 ft lb......

nick

Looks like you have been busy taffy.

I'll go for 410 bhp at 1.5 bar. Good luck with the mapping mate.

437..good luck

398 but i hope its more.

come on then - what were the results?.....

Car is staying with Leighton for a week so it'll be next Thursday/Friday before the results are in

ah, I see - I'll keep an eye on your mood smiley then - will it be a , a , a or a ....

378.2 (dont ask me where the .2 came from) lol - its like a raffle aint it.

what d'you win ??

R00

415Bhp is my guess. You can keep the photo lol.

407bhp

Any news yet Taffy?

Not yet. One of the injectors Leighton fitted has a slight problem when it gets hot so we are waiting for a replacement.

The results are in

And the winner is - Nobody yet.

The turbo decided to pack up on the RR this morning. It had only done 400 ish miles (just out of its warranty as well)

I spoke to Leighton today and he said all was going well until it packed up. So I have just purchased a new turbo which will be shipped to Flea this week for fittment and completion of the mapping. Pretty sure he has some graphs for this mornings run's so I will post them up when I get them.

The new turbo is a GT3071r, .86 housing.

Anyone care to guess again ?

429bhp on the GT2871r and 477bhp on the GT3071r.

New turbo - 456 BHP

Ah, tough luck Taffy But tuning's supposed to be expensive, right? I'm sticking to my original guess, which I can't remember

3071 will be pretty laggy - probably won't come in until well after 4,000rpm, but when it does, it will fly

I guess 475bhp

463

D'oh! didn't realise it was a different model turbo. New guess:

468BHP

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

Nice one! Thats a good healthy figure, do you know what boost setting that was on?

1.7 bar but I think it's just spiking to that then tailing off.

My guess was +24BHP (456 BHP) - where do I come in the competition?

Not sure on position.

Nick D was closest with 428bhp so he wins the picture of Pinin

That guess was for the OLD turbo - not the new (larger) one! 383BHP made I think - so his guess was +45BHP!!!

True, but your guess was also for a different turbo. So with some many guesses and so many turbo's its easier for me to just go with the closest

My 456BHP guess was after your 7th May post with the new 3071r turbo;

The new turbo is a GT3071r, .86 housing.

Anyone care to guess again ?

I didn't amend it for the 0.64 A/R housing...

Johnnybravo was closest with this post:

#1211561

He said 420 BHP!!!

Not an accurate enough guess. John has also has relations with pinin (among other forumers) so I've been told, so has no need for the picture

I guessed 429bhp so I'm the closest!

So you are! Well done!

I missed that one Jay. PM me your address mate

Good result there Adam

So when do you collect to finish off the odds and sods

Tomorrow afternoon . It's going to be a very busy day tomorrow.

You'll get it all done, we manage somehow

Hope all goes well, I'm here all day tomorrow if you do need to drop in for anything, but at 11pm we're gone

Your on speed dial now

Nice one Adam, enjoy Spa

What clutch do you have Taffy?
Also any graphs yet?
And what is it making at say, 1 bar and 1.2 bar?
And when do you get full boost by?

Cheers.