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Steve, here is the 91 octane dyno for comparison to the 7GT2RS above. The area under the curve is excellent. Note we are running the motor to 7500 v. 6500 on the RS and running 1.2 bar v. 1.6 on the RS. Interestingly, the turbos I am using have the same compressors as the 7GT2RS turbos. Boost is essentially immediate. I'll post a wrap up to the build once we get the tuning complete. A more aggressive higher octane file would net 20-30 hp more but as hard as I run the motor I like the tuning to be very conservative. The data log I have from the dyno run shows zero ignition retard on all the cylinders which tells me this is very conservative. Ignore the AFRs on the graph as they are incorrect due to the fact that the probe was not inserted properly on one side thus giving a false reading. The data log from the dyno shows AFRs right at 12.0 across the board when under load. Lap times are a bit quicker, maybe just about a second per 2 minute lap. The problem is the fact that I have more power and torque than I can use with the available traction that I have. I'm testing a Cup wing on the car next week. Cheers...
[url=https://flic.kr/p/vqFY49]
i think the biggest restriction would be that ugly unobtanium exhaust . ill be happy to take it off your hands!
You will LOVE the wing John. I call it aero-courage and it will change your life on track. You will be pushing in no time
J/K, with the RUF bumper she will feel nice. On the GT2 front (even properly ducted) I needed more front down-force with a 996 cup wing.
I agree Sam. I have added the dive planes and the wheel well air diverters on my car and it has improved the front end bite in a subtle way. The rear wing will tie it together..
sadly cant afford the gt3 seats just now ( seen your pics, they're awesome ) but am however putting away a bit here n there for the manthey's if you happen to pull off that group price
i cant believe the rear shot of your engine comp! would fool ANYone you're unbelievable john. godspeed lol
Thanks Mark. I like to fly under the radar. There is actually quite a bit more room back there now that the fuel filter, fuel cooler, and A/C compressor are gone. I plan on calling Manthey tomorrow to get the skinny on the inlets. I keep forgetting about it..
Thanks Mark. I like to fly under the radar. There is actually quite a bit more room back there now that the fuel filter, fuel cooler, and A/C compressor are gone. I plan on calling Manthey tomorrow to get the skinny on the inlets. I keep forgetting about it..
i just saw your wheel well diverters. not even gonna ask! argh ( speechless.. lol )
yes, please! on the manthey's? it'll induce ( sorry lol ) me into calling sam for the 7.2 i/c's which will accompany them
+1^^ Hey Steve. I haven't had a chance to do the write up but the motor is doing great. I have right at 1800 miles on it with +700 track miles. We are still fine tuning the programming and running a very conservative tune right now. We did a preliminary dyno run last week and on a Dynojet the car put down 599 hp and 672 ft.lb to the wheels. The car now puts down the same power as before the rebuild about 400-500rpm earlier in the power band. At 4000rpm, torque peaks at 672 ft.lb and hp exceeds 500 increasing to 599 by the 7500 redline. Essentially, above 4000rpm, whp is in the upper 500 range all the way to redline. At 4000rpm, we are seeing +100hp/+150ft.lb than before.
The dyno run was done at 79F with 37% humidity. It was run in 4th gear from 2000 to 7600rpm peaking at 147mph. This is on a 91 octane tune running 1.2 bar with a MAF and 5" 100cell HJS motorsport cats. Engine is 100% emission compliant and looks stock on a visual inspection. I actually just got my emissions done last month. The temperatures on this dyno run were about 10F higher with 30% higher humidity than the dyno run prior to the rebuild and the car was heat soaked with starting IATs of 130F and no fans on the intercoolers. When I get it on the dyno on a cooler day I can get a better comparison. Overall the car rips. Virtually zero lag, boost in immediate. I can't think of any downsides.
Would love to know more about your setup. Any photos? Who tuned? How does the car drive?
Pics below. Almost everything about the build can be found from RennTrack's 996 turbo section, there's a long thread, about a long process... Tuned locally, had last spring just below 600 hp and 800 Nm (crank) at 1.2 bar. Some alterations since, but no dyno trip.
Wow! Your lower rpm torque is massive and your HP curve looks like a very good torque curve
Very impressive. I can see why traction is a problem. Have you driven in the wet yet?
I hope I can come close to this.
I've overlaid your dyno chart on the GT2RS's. Streetability is good too?
Wow! Your lower rpm torque is massive and your HP curve looks like a very good torque curve
Very impressive. I can see why traction is a problem. Have you driven in the wet yet?
I hope I can come close to this.
I've overlaid your dyno chart on the GT2RS's. Streetability is good too?
Streetablity is excellent. Drives like stock. Engine response is instantaneous due to the simple fact that the displacement is larger and all the rotating components in the engine are lighter. The ported K16 turbine housings and zero clearanced compressors obviously play a part in an essentially instant spool up. I'm actually thinking about having my turbo builder put together a set of similar zero clearance turbos but on a K24 frame to see how they would compare. I would be willing to give up some of the low end grunt (which I have almost too much off) in exchange for some more top end. We'll see. On street tires 1st and 2nd gear are basically useless but on track with sticky R compounds the car hooks up nicely. I have taller 997GT2RS gearing along with a 26.4" rear tire which helps tremendously by effectively making the gearing much taller thank stock. Re-gearing the box is a virtual must if you end up running appreciably more power than stock. No I have not run in wet as all my tires are basically slicks. Overall this set up works very well considering its 100% emissions legal and visually doesn't give anything away to the stock engine. I'm very happy with the performance we're getting on relatively modest 1.2 bar of boost compared to 1.6 on the RS. The one thing I'm running up against now is maxing out the intercoolers in prolonged track work in +35C ambient temps while on relatively low speed technical track. I've researching various options and it appears that the only intercooler which would provide quantifiable benefits over the 997.2s for my type of use would be ones with Secan or Aerospace Marston cores. I'm in the process of getting some quotes for the Marston Core ICs but I doubt I could justify their cost.
Last edited by pwdrhound; Jul 9, 2015 at 04:30 PM.
Streetablity is excellent. Drives like stock. Engine response is instantaneous due to the simple fact that the displacement is larger and all the rotating components in the engine are lighter. The ported K16 turbine housings obviously play a part in an essentially instant spool up. I'm actually thinking about having my turbo builder put together a set of similar zero clearance turbos but on a K24 frame to see how they would compare. I would be willing to give up some of the low end grunt (which I have almost too much off) in exchange for some more top end. We'll see. On street tires 1st and 2nd gear are basically useless but on track with sticky R compounds the car hooks up nicely. I have taller 997GT2RS gearing along with a 26.4" rear tire which helps tremendously by effectively making the gearing much taller thank stock. Re-gearing the box is a virtual must if you end up running appreciably more power than stock. No I have not run in wet as all my tires are basically slicks. Overall this set up works very well considering its 100% emissions legal and visually doesn't give anything away to the stock engine. I'm very happy with the performance we're getting on relatively modest 1.2 bar of boost compared to 1.6 on the RS. The one thing I'm running up against now is maxing out the intercoolers in prolonged track work in +35C ambient temps while on relatively low speed technical track. I've researching various options and it appears that the only intercooler which would provide quantifiable benefits over the 997.2s for my type of use would be ones with Secan or Aerospace Marston cores. I'm in the process of getting some quotes for the Marston Core ICs but I doubt I could justify their cost.
talk to sean at srm about the turbos. he has some efr turbos that make huge power if you want but spool isn't bad at all. in regards to tires is there any room left with the 26.4 rubber? i have the same trans setup with gt2rs gearing and 12" rims and 45et offset
talk to sean at srm about the turbos. he has some efr turbos that make huge power if you want but spool isn't bad at all. in regards to tires is there any room left with the 26.4 rubber? i have the same trans setup with gt2rs gearing and 12" rims and 45et offset
I'm not looking to change tuners. If I did anything I would have Kevin build a set of turbos for me. Just thinking out loud. Honestly I don't think there's any need for it as Kevin's "non billet" K16s are pretty friggin amazing. I might actually go with a slightly taller 3rd and 4th to match the gearing better to the torque curve of the engine. If Sean can get the Marston cores I might see what he could do with regards to the intercoolers.
Steve, there is very little room left with 26.4 rubber especially if you are running low ride heights like I am. With the taller rear you will need to lower the rear of the car 1/2" if you want to keep the same ride height as with the shorter 315/30s which is what I'm assuming you are using. This will obviously reduce your margins even more but for a straight line set up you don't need to run very low. You will need to have the fenders rolled aggressively and run the GT2 liner brackets. 12" 40et wheel is ideal. If you are running fairly soft springs with a bunch of compression it probably won't work. I'm on 1500lb rates.
Last edited by pwdrhound; Jul 9, 2015 at 02:31 PM.
Powdrhound your engine bay looks basically stock.I like the way you do things= always neat/first class.
Thank you. I like to keep things on the car OEM to the greatest extent possible. The majority of stuff on my car are factory Porsche parts. I prefer to stay away from aftermarket parts to the greatest extent possible.
Last edited by pwdrhound; Jul 9, 2015 at 02:20 PM.
you're unbelievable john. godspeed lol
