'Little Bandit' makes 393.5 BHP @ 10 psi...with weird result

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Dragmera

New Member
Well as some of you may know, I had the car at the dyno. today to see what it was making with the addition of the new turbo & intake manifold.

Intial results are quite good at 393.5 BHP at just 10 psi, but the weird thing was where it made the peak power...right on the rev limiter at 8228 rpm!!!

The engine is at the stage now where it needs mapped on the dyno, as it was running lean (about 14.5) from pretty much idle to 6000 rpm, hence the much lower torque figures.

However, regardless of the results, it shows that there is plenty more to come.

With the lean running issue, is is doubtful that I will get up to Knockhill this Sunday (sorry for those who wanted a shot), but I'm sure you can understand that it is not worth risking the engine!

Here's the dyno. graph...



Compare this to the last time the car was on the dyno. with the GT28RS (0.64AR) & stock intake manifold (port matched, polished & 70mm N1 TB).

Boost at 14psi & 20 psi...




The only additions have been the O2 Induction manifold & the new AET Engineering hybrid turbo, called the GT297153R.

The spec. of the turbo is as follows...

GT30 STYLE SMALL TRIM TURBINE WHEEL
GT35 COMPRESSOR WHEEL
0.86 A/R Turbine Housing (INTERNAL WASTEGATE)
0.5 A/R Compressor Housing
WATERCOOLED.
10 PSI Actuator

Connections : T/HSG - T25 STYLE INTAKE + DISCHARGE
C/HSG - 2.75" INTAKE (HOSE), 2" DISCHARGE (HOSE)

Any ideas why there has been such a shift in the power band?

Cheers

Dave

P.S. There were 2 runs as the operator didn't want to rev the engine as high as 8200 rpm on the first run...LOL!!!
 
GTiR_Mic

GTiR_Mic

New Member
Hey Dave how you doing?

Good to see more great results from little bandit. You managed to get the traction situation sorted out yet?

How many shafts are you going to snap with this power then :lol:

Mic
 
T

tro||

Guest
my guess is the design of the inlet manifold has shifted the power band further up the revs,

what i cant understand is how the car made max power at the wheels and fly at different revs, one relates to the other, even with transmission losses taken into account the higher the fly figure the higher the power will be at the wheels.
 
D

Dragmera

New Member
Yeah I thought that about the wheel & flywheel figure as well...

Weird eh?

I'll need to ask the next time I'm up at the dyno.
 
Fire & skill

Fire & skill

Vintage member
8200 rpm - is that safe? :lol:

it may help with traction if its coming in that late. how does it feel in comparison to the GT28? does it feel quicker on the road
 
D

Dragmera

New Member
Fire & skill said:
8200 rpm - is that safe? :lol:

it may help with traction if its coming in that late. how does it feel in comparison to the GT28? does it feel quicker on the road
Click to expand...
Yeah, the engine's built to take the revs.

Spool time is very similar, thanks to the similar sized housings, and as for on the road it feels just as 'tyre spin tastic' as it did before...LOL!
 
Fusion Ed

Fusion Ed

Active Member
As tro|| pointed out. Odd results, as I just posted on exactly the same post on the MSC, For a turbo very similar to a 3071 your torque curve is odd, and the fact its not on the same scale as the BHP makes it a non standard comparison to any other graph thats done the right way. It looks as though you may have boost creep. However like you said get the mapping right and it should give you the midrange that should be there.
 
Fast Guy

Fast Guy

Moderators
Staff member
Either the leanness is trimming some of the power below 8228 and with the correct fuelling it would peak at say 7500rpm for example then start tailing off, or maybe you have improved things and now need a higher rev limit to reach your new max power.
 
D

Dragmera

New Member
That may be the issue...

I think the intake manifold has pushed the power band up by quite a bit.

This is the manifold for those who haven't seen it...

 
B

bracpan

Active Member
The torque seems to be low compared with the BHP is there any main reason for this. AET recomended one of these turbo's over a 3071. I need a higher torque figue that that. Any idea's ? Impresive installation nice work.
Cheers
Phil
 
Fast Guy

Fast Guy

Moderators
Staff member
bracpan said:
The torque seems to be low compared with the BHP is there any main reason for this.
Phil
Click to expand...
It's because the bhp is made at 8200rpm, so torque is lower. If it made the same bhp but at say 6200rpm then the torque would be substantially higher.


There's been a few high power (400+) cars on here before that all have low torque, say 280ish. all of them have made max power at about 7500rpm ish.
 
campbellju

campbellju

Moderators
Staff member
Looking at your old GT28RS, that seems like a lovely HP and Torque plot.

Looking at the plot, its as if you've fitted a T06 or something that hasn't come on boost yet until so late that the engine has run out of lungs?

Thinking out loud, is it because you're turbo pressure is set so low at 0.7Bar that you're wastegate is just bleeding air all the time and your turbo is doing stuff all and that's why you have no torque either?

Check the turbine and compressor maps to see if they can run at that low a pressure.
 
campbellju

campbellju

Moderators
Staff member
to|| said:
what i cant understand is how the car made max power at the wheels and fly at different revs, one relates to the other, even with transmission losses taken into account the higher the fly figure the higher the power will be at the wheels.
Click to expand...
Its simple, the RR operator broke the laws of Physics..... or its a glitch in the software when rounding up/down as the two reference points look identical HP on the plot anyway.
 
D

Dragmera

New Member
It may be due to the fact that the turbo is working at that boost level and needs maybe a minimum of 13-15 psi to operate correctly.

I am mapping the car this Wednesday, so hopefully I will have some better results by then.

Thanks

Dave
 
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