GT3 Cup exhaust and cat delete
11-06-2009, 12:43 PM
#46
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11-06-2009, 12:57 PM
#47
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I only heard it over the phone - its got a bark like a Cup car (not surprisingly).
I'm back in town on Weds and on track next w/e at Barber. I'll know a lot more then.
Dyno will have to follow the week after but we can do before and after comparison but note on stock motor and map with aftermarket headers + stock cats (no mufflers) vs. no cats + this exhaust. Will also weigh it.
FWIW- I took the car to a place that does ALMS prep and support and the head mechanic said that whoever made them was a craftsman- so at least they are well built it seems.
I'm back in town on Weds and on track next w/e at Barber. I'll know a lot more then.
Dyno will have to follow the week after but we can do before and after comparison but note on stock motor and map with aftermarket headers + stock cats (no mufflers) vs. no cats + this exhaust. Will also weigh it.
FWIW- I took the car to a place that does ALMS prep and support and the head mechanic said that whoever made them was a craftsman- so at least they are well built it seems.
11-06-2009, 12:59 PM
#48
Rennlist Member
Sounds great , I can't wait to hear how they turn out.
Thanks,
Thanks,
I only heard it over the phone - its got a bark like a Cup car (not surprisingly).
I'm back in town on Weds and on track next w/e at Barber. I'll know a lot more then.
Dyno will have to follow the week after but we can do before and after comparison but note on stock motor and map with aftermarket headers + stock cats (no mufflers) vs. no cats + this exhaust. Will also weigh it.
FWIW- I took the car to a place that does ALMS prep and support and the head mechanic said that whoever made them was a craftsman- so at least they are well built it seems.
I'm back in town on Weds and on track next w/e at Barber. I'll know a lot more then.
Dyno will have to follow the week after but we can do before and after comparison but note on stock motor and map with aftermarket headers + stock cats (no mufflers) vs. no cats + this exhaust. Will also weigh it.
FWIW- I took the car to a place that does ALMS prep and support and the head mechanic said that whoever made them was a craftsman- so at least they are well built it seems.
11-20-2009, 04:17 PM
#49
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Thread Starter
Update- sorry more anecdotal (non-empirical) info.
I was at Barber with PBOC last w/e with the car. Aside from a few minor issues and a fuel p/u issue on hard right handers the car ran well. The car spools quickly, revs freely and pulls hard from 4.5k to 7k, so I'd guessi somewhat predictably some tq loss and hp gain. But remember we just instituted a new LWF AND the new exhaust so hard to isolate the perceived effects. Regardless, together they seem to work well.
Also first time since X51 baffle, oil separator, deep sump and new valves installed.
As for sound, in person (not over the phone) the car idles fairly quietly with a lower freq. Tubi-type sound if you know what I mean. I was surprised at how quiet (relatively) it was. My 964 with 3.8 and similar (dual) exhaust is very much louder at idle- I'd guess +5db at least.
At 5-7k the car howls like a cup car. My support took some videos but they awful- I'll upload this w/e. But here are a few snaps fwiw.
Planning on dyno next week so finally some data with stock map. Its running (understandably) rich so a Steve Weiner remap is in the future so I should have a variety of runs to share.
I was at Barber with PBOC last w/e with the car. Aside from a few minor issues and a fuel p/u issue on hard right handers the car ran well. The car spools quickly, revs freely and pulls hard from 4.5k to 7k, so I'd guessi somewhat predictably some tq loss and hp gain. But remember we just instituted a new LWF AND the new exhaust so hard to isolate the perceived effects. Regardless, together they seem to work well.
Also first time since X51 baffle, oil separator, deep sump and new valves installed.
As for sound, in person (not over the phone) the car idles fairly quietly with a lower freq. Tubi-type sound if you know what I mean. I was surprised at how quiet (relatively) it was. My 964 with 3.8 and similar (dual) exhaust is very much louder at idle- I'd guess +5db at least.
At 5-7k the car howls like a cup car. My support took some videos but they awful- I'll upload this w/e. But here are a few snaps fwiw.
Planning on dyno next week so finally some data with stock map. Its running (understandably) rich so a Steve Weiner remap is in the future so I should have a variety of runs to share.
11-20-2009, 08:31 PM
#50
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FWIW my 99', 3.4 was protested when I weighed 2790 after Qual at a NASA event 2 weeks ago. I dyno'd at 249 with straight pipes, 91 octane, and stock ECU with a lightweight flywheel. They used a 248 Dynojet, smoothing factor of 4. My A/F rates were in the high 12's- low 13's across the range. The National's champion GTS3 996 was also dyno'd right before me turning 255 rwhp and his A/F mixtures were leaner in the mid 14's. Midrange from 4k-6k he had 15 more HP and torque than mine. Regardless I beat him and all the protesting BMW's too....
The good news is I had set my weight based on 255 rwhp. Now I get to drop another 50lbs. and said thanks to all those protesting Beemer driver's. My car weighed 2620 on fumes with all OEM steel and glass...
11-21-2009, 10:56 AM
#51
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Thread Starter
Did you use the Motorsports dual-chamber AOS and if so, any issues making it fit?
FWIW my 99', 3.4 was protested when I weighed 2790 after Qual at a NASA event 2 weeks ago. I dyno'd at 249 with straight pipes, 91 octane, and stock ECU with a lightweight flywheel. They used a 248 Dynojet, smoothing factor of 4. My A/F rates were in the high 12's- low 13's across the range. The National's champion GTS3 996 was also dyno'd right before me turning 255 rwhp and his A/F mixtures were leaner in the mid 14's. Midrange from 4k-6k he had 15 more HP and torque than mine. Regardless I beat him and all the protesting BMW's too....
The good news is I had set my weight based on 255 rwhp. Now I get to drop another 50lbs. and said thanks to all those protesting Beemer driver's. My car weighed 2620 on fumes with all OEM steel and glass...
FWIW my 99', 3.4 was protested when I weighed 2790 after Qual at a NASA event 2 weeks ago. I dyno'd at 249 with straight pipes, 91 octane, and stock ECU with a lightweight flywheel. They used a 248 Dynojet, smoothing factor of 4. My A/F rates were in the high 12's- low 13's across the range. The National's champion GTS3 996 was also dyno'd right before me turning 255 rwhp and his A/F mixtures were leaner in the mid 14's. Midrange from 4k-6k he had 15 more HP and torque than mine. Regardless I beat him and all the protesting BMW's too....
The good news is I had set my weight based on 255 rwhp. Now I get to drop another 50lbs. and said thanks to all those protesting Beemer driver's. My car weighed 2620 on fumes with all OEM steel and glass...
Anyway fwiw here are the video links (can't embed for some reason- can someone?); ones too short, the other too long and they both stink. I suspect the guy who shot it was high, but they'll give you an idea on the sound:
http://vimeo.com/7730841
http://vimeo.com/7730618
12-29-2009, 04:26 PM
#52
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I wasn't present but I'm told the car just did 284 whp/ 248 tq @ 6800 on Dynojet (on pump gas). AFR was circa. 12.5 and it was still pulling to 6800 apparently. That's with the custom exhaust and Steve Weiner map.
Maybe its all the map but those are the numbers. When I get the logs I'll post.
Maybe its all the map but those are the numbers. When I get the logs I'll post.
12-29-2009, 06:25 PM
#53
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I wasn't present but I'm told the car just did 284 whp/ 248 tq @ 6800 on Dynojet (on pump gas). AFR was circa. 12.5 and it was still pulling to 6800 apparently. That's with the custom exhaust and Steve Weiner map.
Maybe its all the map but those are the numbers. When I get the logs I'll post.
Maybe its all the map but those are the numbers. When I get the logs I'll post.
12-29-2009, 06:46 PM
#54
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Thread Starter
Yes 3.4. To be clear we also have a LWF but that should not add any hp- just increase "spool up". I forgot- we do also have some eBay specials on there for headers. They looked good and we cleaned them up slightly but doubt they add too much- if anything just a drop in weight- MAYBE slight hp gain.
I would have liked to have given you all an individual breakdown of what each change contributed but it would have been too time consuming it was really the combined effect I was after. Sorry.
p.s. Note I've taken the "Spec" out of my signature.
I would have liked to have given you all an individual breakdown of what each change contributed but it would have been too time consuming it was really the combined effect I was after. Sorry.
p.s. Note I've taken the "Spec" out of my signature.
12-29-2009, 10:03 PM
#56
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Possibly. I tried to do things that would allow us to easily revert to Spec as needed but I just couldn't stop. Basically I'm an idiot.
Unless "Spec Plus" ( I just made that up) ever evolves I may be relegated to NASA/PBOC.
But notice we also have Spec Boxster in the making. I haven't driven one yet but I'm advised it'll school the 996.
Unless "Spec Plus" ( I just made that up) ever evolves I may be relegated to NASA/PBOC.
But notice we also have Spec Boxster in the making. I haven't driven one yet but I'm advised it'll school the 996.
12-29-2009, 10:12 PM
#57
The Penguin King
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12-29-2009, 10:28 PM
#58
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12-30-2009, 08:02 AM
#59
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Your adviser needs to get off the pipe. I'm 6 seconds faster than the fastest SB at Willow Springs, 5 seconds faster at Buttonwillow, 7 seconds faster at Cal Speedway, and 5 seconds faster at Laguna. I did race a early Boxster with a 3.4 at Miller and that was comparable......
12-30-2009, 11:28 AM
#60
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Your adviser needs to get off the pipe. I'm 6 seconds faster than the fastest SB at Willow Springs, 5 seconds faster at Buttonwillow, 7 seconds faster at Cal Speedway, and 5 seconds faster at Laguna. I did race a early Boxster with a 3.4 at Miller and that was comparable......
