Racecar Project - Race Engine #2
#1
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After quite some time, and very much late into the season, I have finally put together my new racing engine and dyno tuned it on Saturday. There are a significant number of changes that were made over the old engine, some in terms of longevity, and others in hopes for 25whp more or about 360whp. I did not change the intake system, exhaust system, or cylinder heads and valve size, but most everything else was changed. I was able to drop .75lbs off of EACH connecting rod & piston combination and significantly reduced the rotating assembly of the clutch & flywheel by using a carbon/carbon clutch with a small flywheel. The result is very noticable and the new engine does not want to idle much under about 1700rpm because it has less inertia to keep it running.
I was so shocked by the first pull which resulted in 394whp that I looked at the dyno calibration to see if anything had been changed. It had not. The end result of the tuning is what you see below 322wtq and 412whp. To put this in context, a 2000 unrestricted GT3R engine (3.6l) shows 289wtq and 421whp!!! I went back to the dyno today to run some additonal tests to ensure that the results were valid and they repeated Saturday's test. I further put a known car on the dyno and compared it against prior tests and it showed the same. So, I guess this is real and the real test will be tomorrow at LRP when I test the car.
Where did the power come from?
1) Ninemeister rocker arms. I believe this small and overlooked piece of the engine is responsible for the largest portion of the power increase. Due to its design, I was able to radically change the camshaft profile to better optimize the valve motion.
2) Piston Rings. I believe the second largest improvement comes from the race piston rings and the reduction in frictional losses that occurs.
3) Lightweight rotating mass. Nothing compares to weight reduction, whether in the chassis, or the engine.
Although there was a displacement change, I don't believe this significantly added to the power of the engine. I really have to thank Colin for taking the initiative and funding the cooled development activities and I think that this engine which was built independantly from 9M validates what he has been showing over the past several years. I feel confident that I've done my due digillance and the numbers represented are in fact correct.
Test Scenario:
Fuel Type - Mobil 1 93 Octane street fuel
Correction method - SAE
Air Temperature - 91.1
Barometric Pressure - 29.922
Ramp Rate - 300rpm/sec
Below is a comparison of my old engine to my new engine. The new engine would not take full throttle much below about 2700rpm, so I started the pull at 3500 but with the same 300rpm/sec rate I run all of my tests at. I can see that the torque falls off at a higher rate than the old engine which might suggest that the intake valve, intake port, throttle body diameter, or intake camshaft lobe profile needs to be improved. I'm sure Colin will have some ideas and I'll probably revisit it at some point in time.
Enjoy
I was so shocked by the first pull which resulted in 394whp that I looked at the dyno calibration to see if anything had been changed. It had not. The end result of the tuning is what you see below 322wtq and 412whp. To put this in context, a 2000 unrestricted GT3R engine (3.6l) shows 289wtq and 421whp!!! I went back to the dyno today to run some additonal tests to ensure that the results were valid and they repeated Saturday's test. I further put a known car on the dyno and compared it against prior tests and it showed the same. So, I guess this is real and the real test will be tomorrow at LRP when I test the car.
Where did the power come from?
1) Ninemeister rocker arms. I believe this small and overlooked piece of the engine is responsible for the largest portion of the power increase. Due to its design, I was able to radically change the camshaft profile to better optimize the valve motion.
2) Piston Rings. I believe the second largest improvement comes from the race piston rings and the reduction in frictional losses that occurs.
3) Lightweight rotating mass. Nothing compares to weight reduction, whether in the chassis, or the engine.
Although there was a displacement change, I don't believe this significantly added to the power of the engine. I really have to thank Colin for taking the initiative and funding the cooled development activities and I think that this engine which was built independantly from 9M validates what he has been showing over the past several years. I feel confident that I've done my due digillance and the numbers represented are in fact correct.
Test Scenario:
Fuel Type - Mobil 1 93 Octane street fuel
Correction method - SAE
Air Temperature - 91.1
Barometric Pressure - 29.922
Ramp Rate - 300rpm/sec
Below is a comparison of my old engine to my new engine. The new engine would not take full throttle much below about 2700rpm, so I started the pull at 3500 but with the same 300rpm/sec rate I run all of my tests at. I can see that the torque falls off at a higher rate than the old engine which might suggest that the intake valve, intake port, throttle body diameter, or intake camshaft lobe profile needs to be improved. I'm sure Colin will have some ideas and I'll probably revisit it at some point in time.
Enjoy
![](http://www.racetek-engineering.com/images/New%20EngineGraph.jpg)
#2
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The numbers are real alright. We saw 430 at the flywheel from the last low-lift 3.82 litre 9m Race engine we built, add around 20-25hp from the high lift cam package, plus a bit more for the reduced inertia meaning that more of the power is going into the transmission. I kind of expected 450-460 at the flywheel, but this looks likely to be a little more, not sure what the hub-to-flywheel hp conversion is, but if we assume 460hp it works out at 120hp/litre, so not that far off my target of 125hp/litre that I declared in my previous posts. Well done.
Expect a 'phone call from our friend Bob real soon.
Expect a 'phone call from our friend Bob real soon.
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These are staggering results. Congratulations Geoffrey and Colin!
For contrast, my 3.8 RSR Sprint engine makes a puny 350 rwhp and 290 ft/lbs. I cannot overstate how impressed I am with this.
On the other hand, this is probably going to cost me a lot of money!
Geoffrey, you should try the short trumpets! Something is holding this engine back on the top end. 430 rwhp is there with some tuning.
Chris Cervelli
Spline Technologies
For contrast, my 3.8 RSR Sprint engine makes a puny 350 rwhp and 290 ft/lbs. I cannot overstate how impressed I am with this.
On the other hand, this is probably going to cost me a lot of money!
Geoffrey, you should try the short trumpets! Something is holding this engine back on the top end. 430 rwhp is there with some tuning.
Chris Cervelli
Spline Technologies
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Geoffery, Colin,
So what's the skinny on the rockers? Is this a revised cam with a rocker ratio change, or a different geometry that allows for a steeper ramp angle to increase duration? it's pretty amazing to get this amount of power, but even more amazing is that the revs haven't been pushed to crazy levels to get it! What kind of compression are you running? wow...
So what's the skinny on the rockers? Is this a revised cam with a rocker ratio change, or a different geometry that allows for a steeper ramp angle to increase duration? it's pretty amazing to get this amount of power, but even more amazing is that the revs haven't been pushed to crazy levels to get it! What kind of compression are you running? wow...
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Do a search here on "9M Rocker Arm" which details the geometry testing I did. The short of it is that the stock rocker arms vary in ratio due to their production tolerances but the 9Ms are exactly the same. What that means is that the cam timing is different on different cylinders with different stock engines where the cam timing is exactly the same with the 9M rockers. My new engine sounds much smoother than the old engine. The 9M rocker ratio is the same as the Porsche specification, it has not been altered. The largest change is that the pad that runs on the camshaft is longer which allows the cam profile to be altered beyond what is physically possible with a stock 964 or 993 rocker arm. This is where the power comes from.
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9m billet alloy steel, DLC coated rocker next to Porsche RSR adjustable rocker for caomparison. The DLC coating (Diamond Like Carbon) significantly reduces friction and wear.
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Very interesting...
since the compression ratio doesn't seem to be that crazy with the ability to run on pump gas, and the rpm range shifted up but not as radically as I would expect, it seems that this is a modification that could offer some real potential on even moderately tuned motors? Or is the cam timing such that it has shifted the whole rpm band up which really narrows the low end power band? It seems to come on like a rocket at 4K! wow... nice job colin!
since the compression ratio doesn't seem to be that crazy with the ability to run on pump gas, and the rpm range shifted up but not as radically as I would expect, it seems that this is a modification that could offer some real potential on even moderately tuned motors? Or is the cam timing such that it has shifted the whole rpm band up which really narrows the low end power band? It seems to come on like a rocket at 4K! wow... nice job colin!
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If things go according to plan, the same package of production 9m Racing parts (heads, cams, valves, springs, rockers, cams, intake, exhaust) that were running on my RS engine are destined to be fitted to a special project 4.0 litre street engine. The intended motor is already running Motec and will be mapped on an engine dyno, hence verifying the results we have achieved to date. Our estimates predict a tractable 100-110hp per litre for this road only engine on pump fuel, meeting the necessary emissions standards.
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There are loads of ideas yet to be tested, for instance we're currently assembling a street-sleeper 964 road car with a 964RS engine & 6 speed 'box, I'm going to fit the M600 ecu from my race car and will be soon building a wiring loom to run it as a drive-by-wire with the late model GT3 throttle body, may even try the GT3 intake manifold if I can make it fit.
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Geoffrey & Colin,
Congratulations on an engineering masterpiece!
You've turned around a lot of old thinking. Including mine.
That torque curve - if you can call it a curve - more closely resembles
one of my diesel ag engines.
"...may even try the GT3 intake manifold if I can make it fit."
You'll have fun with that. :-)
Congratulations on an engineering masterpiece!
You've turned around a lot of old thinking. Including mine.
That torque curve - if you can call it a curve - more closely resembles
one of my diesel ag engines.
"...may even try the GT3 intake manifold if I can make it fit."
You'll have fun with that. :-)
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Cheers Noah.
In the overall scheme of development it has been critical that Geoffrey validate my results with his own engine, tested using his own methods. I'm now more than happy to see that the results he has now achieved with his engine have clearly matched if not surpassed my efforts, to the point where I'm now looking forward to taking my engine further up the ladder. The whole process has been an upstream slog made harder by the torrent of doubt, so I cannot thank Geoffrey enough for being the only one to truly believe in the work I have been doing (for the last 9 years...).
In the overall scheme of development it has been critical that Geoffrey validate my results with his own engine, tested using his own methods. I'm now more than happy to see that the results he has now achieved with his engine have clearly matched if not surpassed my efforts, to the point where I'm now looking forward to taking my engine further up the ladder. The whole process has been an upstream slog made harder by the torrent of doubt, so I cannot thank Geoffrey enough for being the only one to truly believe in the work I have been doing (for the last 9 years...).