Dyno results for GT3

[Gandalf]

I have a Brooke race exhaust (inconel back and side pipes) and was advised to get the car remapped to take account of the larger diameter. I was not expecting large gains just a slight increase in torque/bhp and Litchfield are experts (they have fettled Chris Harris’s Touring). The engine is a G6 and when the gold technicians at Porsche put it in they told me it is essentially a de-stroked 4.0 litre RS engine and they have had no issues with this iteration of engine. What is noticeable about the graph is the red line is now 9,250 and the torque is up across the range. It is a noticeable improvement on stock.

 

[Roro]

I'm crap at reading graphs. But is that basically saying you've gone up from around 480 to 505BHP? Not bad at all, how much was the exhaust? Torque looks like it's gone up around 10-15% which is a good result too (if my number reading is any good)

 

[911UK]

I'm crap at reading graphs. But is that basically saying you've gone up from around 480 to 505BHP? Not bad at all, how much was the exhaust? Torque looks like it's gone up around 10-15% which is a good result too (if my number reading is any good)

that would be my question as well

 

[Gandalf]

I'm crap at reading graphs. But is that basically saying you've gone up from around 480 to 505BHP? Not bad at all, how much was the exhaust? Torque looks like it's gone up around 10-15% which is a good result too (if my number reading is any good)

Yes, torque and BHP up across the board and I asked Litchfield and they said it was all well within tolerance.

You will need to contact Eddy Brooke, as when I bought the car it already had the Brooke back box delete and then I spent quite a bit to have the side box delete, which drops 23kgs from the rear axle. The difference was noticeable within the first mile, as it moves the moment of inertia forward. The good thing is Eddy gives a lifetime warranty, so that is a great help. Inconel is slightly heavier than titanium but has a higher heat tolerance.

 

[Roro]

Am I reading that right, you've removed the centre back silencer and also the 2 side silencers? Isn't the car too loud inside the cabin or too loud for track? (Except Silverstone, Spa and Nordschleife, they're usually not too bothered)

 

[Gandalf]

Am I reading that right, you've removed the centre back silencer and also the 2 side silencers? Isn't the car too loud inside the cabin or too loud for track? (Except Silverstone, Spa and Nordschleife, they're usually not too bothered)

It is fine in the cabin (passengers are surprised, but on long journeys I use noise cancelling headphones), but too noisy for most circuits. I prefer touring and hill climbs (64k miles in total and last year Alps/Dolomites, Spain/Portugal and France) and the car is set up for fast road driving (Tractive plus BBS alloys). I do not track the car, but would probably prefer a Caterham or Ariel for that.

 

[Cunno]

Impressive
Who raised the rpm limiter? If max power at 8600 rpm why raise limit to 9360?

 

[Cunno]

Also where have the stock figures come from?
Did you run your car on this dyno before converting exhaust or are figures from a random 991.1?

 

[Gandalf]

Also where have the stock figures come from?
Did you run your car on this dyno before converting exhaust or are figures from a random 991.1?

The car was run on the dyno before and after, so the stock was my car prior to the remap. They have also done standard cars without any upgraded exhaust (they showed me the dyno of one and it has a similar power gain, but circa 10-15bhp less than mine). I was not expecting a huge uplift in power, just better mid range torque.

 

[Gandalf]

Impressive
Who raised the rpm limiter? If max power at 8600 rpm why raise limit to 9360?

Maximum revs were at 9,000 rpm as stock and it has been raised to 9,250, so well within tolerance. Their dyno is the same used by Porsche and they use it for all their remaps (Litchfield are renowned for their GTRs at 800bhp to over 1,000bhp). They have won numerous awards for their upgrades (they also specialise in the GR Yaris and Alpine).

 

[Cunno]

But why raise the limiter if max power is showing at 8700 rpm? What are you gaining on an engine which is known for having issues when using the high rev limit of the standard engine.
Just seems a risk that doesn’t gain you anything?

 

[Cunno]

Shame it would of been nice to see what difference the exhaust made and then the tune. When I modded my 997 I wish I’d run a base line on the dyno before starting so you can see the real gains. Just wondering whether the G6 version is stronger / more powerful than the standard engine, as you say Porsches rate it as a better unit

 

[Gandalf]

Shame it would of been nice to see what difference the exhaust made and then the tune. When I modded my 997 I wish I’d run a base line on the dyno before starting so you can see the real gains. Just wondering whether the G6 version is stronger / more powerful than the standard engine, as you say Porsches rate it as a better unit

Litchfield have dynos of standard GT3, but I agree I would have liked a dyno before ans after exhaust fitted. Eddy Brooke told me at the time when he fitted the exhaust it would only raise bhp by around 10bhp. Stock is meant to be 467-475bhp and now at 497-505.