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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
Seems like alot of work for what is most likely trading 10-15 ft/lb for 10-15hp. I had a similar setup with a BTR 2 and it did level out ~6500 but still posted a peak HP # at nearly 7k. Perhaps you're feeling some knock retard?
Seems like alot of work for what is most likely trading 10-15 ft/lb for 10-15hp. I had a similar setup with a BTR 2 and it did level out ~6500 but still posted a peak HP # at nearly 7k. Perhaps you're feeling some knock retard?
I guess I never considered there to be an actual problem. The car is a monster to 6k. Peak hp of 544 is at 6k and at 7k it's down to 520. It's not like it falls on its face at 6k, it just doesn't have that vicious pull all the way to redline.
I guess I never considered there to be an actual problem. The car is a monster to 6k. Peak hp of 544 is at 6k and at 7k it's down to 520. It's not like it falls on its face at 6k, it just doesn't have that vicious pull all the way to redline.
Here is the dyno sheet from my car with a BTR 2 (and supporting mods) when the previous owner (03worthy4link above) got it dyno tuned on a Mustang Dyno. As you can see it continued to make power after 6k. It doesn't decrease in power:
Here is the dyno sheet from my car with a BTR 2 (and supporting mods) when the previous owner (03worthy4link above) got it dyno tuned on a Mustang Dyno. As you can see it continued to make power after 6k. It doesn't decrease in power.
Interesting... Is that with stock compression, what octane, and who did the head porting? I'm stock CR, 91 octane and AHP hand ported. Also running stock ported tb. I'll try to post my dyno graph shortly.
Here is the dyno sheet from my car with a BTR 2 (and supporting mods) when the previous owner (03worthy4link above) got it dyno tuned on a Mustang Dyno. As you can see it continued to make power after 6k. It doesn't decrease in power.
Interesting... Is that with stock compression, what octane, and who did the head porting? I'm stock CR, 91 octane and AHP hand ported. Also running stock ported tb. I'll try to post my dyno graph shortly.
From what I gathered from Anthony when purchasing,
Heads milled .025 (Not sure on exact compression, but not stock)
Exhaust porting, but intake side left stock (not sure where this was done. Maybe Alex can chime in here. I PM'ed him)
93 octane
When mine was dyno'd the fuel was over one month old due to waiting for the heads to get ported. Don't know if that matters any. Also, early last summer I finally found out what was causing an unsettling sound when only turning left. One of the down tubes on the passenger header was 1/8-1/4" from the frame at idle. It was eventually replaced and installed free of charge from one of the main if not "thee main" header company. Something about an error in production-one degree off on a bend here leading to greater deviation farther down. Stand-up guys to say the least. I wonder if that tube was making contact during the dyno run as rpm's climbed, maybe pulling some timing.
Nothing is infallible, but BTR does a ton of valvetrain testing with their dual valve springs. Hopefully that's not it. Also, I'm stock CR. AHP only did a cleaning pass on the heads as a safety measure instead of milling 0.010-0.020. I was told higher CR could lead to knock so I opted to not bump up the compression.
Thanks Frankie and to everyone that has chimed in. I appreciate it.
Frankie, I think your dyno graph is one of the only ones I've seen with that or similar cam where hp is basically climbing all the way to 7k. Most of the BTR 2 or similar cam graphs start to fall off a bit on top. There is also a Cordes Performance graph of the TSP 2.2 cam/fbo (15 degrees of overlap) that looks very similar to mine where it starts to decline somewhere around 6k.
Nothing is infallible, but BTR does a ton of valvetrain testing with their dual valve springs. Hopefully that's not it. Also, I'm stock CR. AHP only did a cleaning pass on the heads as a safety measure instead of milling 0.010-0.020. I was told higher CR could lead to knock so I opted to not bump up the compression.
Thanks Frankie and to everyone that has chimed in. I appreciate it.
Frankie, I think your dyno graph is one of the only ones I've seen with that or similar cam where hp is basically climbing all the way to 7k. Most of the BTR 2 or similar cam graphs start to fall off a bit on top. There is also a Cordes Performance graph of the TSP 2.2 cam/fbo (15 degrees of overlap) that looks very similar to mine where it starts to decline somewhere around 6k.
Glad to help, bud! Alex (03worthy4link) is super knowledgeable so maybe he will chime in here soon and help out.
Here is the dyno sheet from my car with a BTR 2 (and supporting mods) when the previous owner (03worthy4link above) got it dyno tuned on a Mustang Dyno. As you can see it continued to make power after 6k. It doesn't decrease in power.
Interesting... Is that with stock compression, what octane, and who did the head porting? I'm stock CR, 91 octane and AHP hand ported. Also running stock ported tb. I'll try to post my dyno graph shortly.
I milled the head .025 total. When CC'd the combustion chamber came out as near to stock as makes no difference so I dont know the effect it had on compression, if any but it was tuned for 93. As for porting the heads were stock on the intake, and ported by AHP on the exhaust. The car does have an MSD intake which I dont recall seeing if you mentioned what intake you were running?
I’m pretty sure milling .030 is around 11.5ish:1 vs 11:1 untouched. I also have street ported/exhaust only heads and MSD intake.
Seems to be a very similar setup. For all intents and purposes i don’t see why the octane alone couldnt be the deciding factor depending on how conservative your tuner was/or was not. I know when I had the car I was tempted to buy one of those dash logic gizmos solely to see if/when the car knocked.
He did say it was a conservative tune. He also said that his dyno readings are 10-15 less than others in the area-which is also backed up by ramairws6 who has commented in this thread and has had his car on their dyno and others around DRM.
I started with the BTR Stage 3 cam. Out of all the ones I've done, it was definitely my favorite. My thrive to gain more power is what led me to change it. It had a lot of midrange punch but fell off up top. It also drove great.
03-11-2019, 03:21 PM
