9m 4.0 litre high lift - 450hp & 400lbft at flywheel - in stock 964RS!
#16
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Thanks Jean, I really appreciate your words of encouragement. Hopefully once the weather clears up in true Rennlist style we will back up the dyno result by posting a sub-10 sec 60-130mph on the DL1, so do keep an eye open for this.
The numbers for the GT3RSR engine are impressive Geoffrey, in comparison this 4.0 litre is currently putting down 358lbft (& 385bhp) at the tyre in 5th gear which is roughly the same torque per cc as the RSR which I assume is a 3.8 litre. The comparitive lack of top end power with our 4.0 litre is an indication of an air flow restriction at this high level of tune, so for experimental purposes we may increase the port size for my 2007 993 Sprint engine build and risk sacrificing a little torque for more top end, we know that the bottom end and valve train is good for 8000+rpm so it would be a shame not to use it more.
As for our target with the GT3, because the crank and rods are interchangeable we are going to make pistons & cylinders and build the large capacity bottom end first which will be a good upgrade for most of the 50,000mile trackday cars which will need a refresh soon. If we leave the heads alone due to cost and we redesign the cams & spring pack then match it with a custom exhaust, I would think that 500fwhp would be a comfortable goal for a road legal car, and of course the upgrade will probably also suit the 997GT3 engine as well so there is a pretty broad market to go at. The intention would then be to manufacture a 9m head/valve/spring/cam assembly that really makes the engine sing, and 150bhp per litre is definitely on the cards for an all-out race engine.
The numbers for the GT3RSR engine are impressive Geoffrey, in comparison this 4.0 litre is currently putting down 358lbft (& 385bhp) at the tyre in 5th gear which is roughly the same torque per cc as the RSR which I assume is a 3.8 litre. The comparitive lack of top end power with our 4.0 litre is an indication of an air flow restriction at this high level of tune, so for experimental purposes we may increase the port size for my 2007 993 Sprint engine build and risk sacrificing a little torque for more top end, we know that the bottom end and valve train is good for 8000+rpm so it would be a shame not to use it more.
As for our target with the GT3, because the crank and rods are interchangeable we are going to make pistons & cylinders and build the large capacity bottom end first which will be a good upgrade for most of the 50,000mile trackday cars which will need a refresh soon. If we leave the heads alone due to cost and we redesign the cams & spring pack then match it with a custom exhaust, I would think that 500fwhp would be a comfortable goal for a road legal car, and of course the upgrade will probably also suit the 997GT3 engine as well so there is a pretty broad market to go at. The intention would then be to manufacture a 9m head/valve/spring/cam assembly that really makes the engine sing, and 150bhp per litre is definitely on the cards for an all-out race engine.
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Originally Posted by NineMeister
Don't tempt me, if Florida had snow in the winter and no gators I would give it more than a little consideration!...
#18
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I was shocked at how much power the 996RSR engine put out. It was an early engine so it was still 3.6l, but we ran it to 8800rpm. I have never, ever in my life ever heard something as loud as that engine. It makes your ears bleed, even with earplugs. The engine had the 138mm rods and 19mm wrist pin slipper 2 ring pistons. A normal race GT3RS (prior model) is in the 425hp range at the wheels unrestricted. With the increased displacement with your crank, rods, pistons, that should improve upon it. Obviously the RSR engine is short hour life engine.
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Originally Posted by epj993
Great work, Colin! BTW, Southern California meets those requirements
Fantastic results indeed...
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Colin,
You would miss the Lancashire accent/ chip shops/ Warrington rugby team !!
Mind you ,down south its OK for a visit but too much sunshine and little rain to moan about !!
Now Nova Scotia ,Canada is much more like it !
Geoff
You would miss the Lancashire accent/ chip shops/ Warrington rugby team !!
Mind you ,down south its OK for a visit but too much sunshine and little rain to moan about !!
Now Nova Scotia ,Canada is much more like it !
Geoff
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Originally Posted by Red rooster
Colin,
You would miss the Lancashire accent/ chip shops/ Warrington rugby team !!
Mind you ,down south its OK for a visit but too much sunshine and little rain to moan about !!
Now Nova Scotia ,Canada is much more like it !
Geoff
You would miss the Lancashire accent/ chip shops/ Warrington rugby team !!
Mind you ,down south its OK for a visit but too much sunshine and little rain to moan about !!
Now Nova Scotia ,Canada is much more like it !
Geoff
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Life is always yin and yang, so whilst Warrington Rugby is doing well (3 wins from 4 games) my favourite football team Leeds are still pressing the self-destruct button and are now firmly bottom of the Championship and look likely to be in the 1st division next year. Ho hum.
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Collin - great job! Your shop always sets the bar at a extremely difficult level. Glad to see someone is still interested in pushing the 993's to their limits.
#25
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Originally Posted by Geoffrey
We are seeing 505rwhp 330rwft/tq from the 3.6l 996GT3RSR sprint engine in factory trim, unrestricted with factory programming. I'd think that you could improve on that.
That's watercooled though
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Originally Posted by David Ray
Collin - great job! Your shop always sets the bar at a extremely difficult level. Glad to see someone is still interested in pushing the 993's to their limits.