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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
I had a goal of getting my ZR1 into the 10's in near-stock form before doing any significant modifications. I knocked that one out of the park last Saturday at Rockingham dragway with 4 back-to-back 10 second passes in a row...! There were very few cars, likely due to them overly promoting an event on Sunday, so few were aware they were doing TnT Saturday --- perfect! The weather was excellent with the exception of heavy winds that started out as a crosswind and quickly turned to a full-on headwind.
Car details:
2009 Corvette ZR1
335/30/18 (worn out) Hoosier Drag radials on 18x13 CCW C14's (a combo I picked up from a forum member awhile back)
Gutted cats
Basic HP Tuners tune that's not really adding any tangible power; primarily turning off the O2 codes. FYI, I found after gutting the cats we had to revert back to stock PE targets since A/F was nearly perfect, and revert back to stock timing as well. Previously with just the tune were able to get a little more aggressive; with no cats ironically the stock mapping was essentially perfect -- go figure..
Lastly, the best mod I've done so far -- deleting the clutch over-center spring -- what a difference it made! Absolutely zero clutch/pedal issues, even hot-lapped, whereas before it would do the typical slow or almost no return on any hard launch.
Awesome and congratulations! Instead of the LPE710 I think Kong Performance makes big power out of ZR1's! The LPE710 is still a monster package and is way faster than me haha!
Thanks! I already have most of the LPE 710 parts, so I'll be going that way for now. I would like to have Kong port my blower at some point, and maybe some other goodies --- we'll see..
Thanks! I already have most of the LPE 710 parts, so I'll be going that way for now. I would like to have Kong port my blower at some point, and maybe some other goodies --- we'll see..
I do not have a ZR1 so I cannot really give good advice on anything except Kong is the go to guy for them haha. I saw where he made 1k rwhp through a stock blower on a ZR1. Good luck on your quest for horsepower!
Congrats. Cool video (inside and out). What RPM did you launch at?
Thanks! Launch RPM for my quickest pass was 4800 according the logs; the runs prior were ~4500. 4800 seemed to be the sweet spot for the track conditions. If it would have held 5000 I think I could have gotten into the 10.50's (or better).
Great work with minimal mods! On your launch are you just revving it up as you watch the Starting lights and slip the clutch out around 4-4500?
Pretty much. I've been experimenting with the launch and what's been most successful thus far is to bring the revs up to say 4000, start to increase throttle/RPM while engaging the clutch with a smooth but quick lift. As soon as I feel the clutch start to grab and the car start to move I go WOT. Long/short is you want the RPM's increasing, i.e., rolling into the throttle as you hit the engagement point. I was progressively increasing the engagement RPM for each run. 4800RPM worked the best on the 10.60 run with a 1.63 60' but it was still bogging too much and dragging the RPM down to 2800 before climbing back up. There is a LOT more in the 60' if the track would hold it. I tried launching higher on the later runs but the track surface was already done (they were not prepping it since there were maybe 15 cars running), and I just ended up spinning. That said, I was not at all trying to cut a good R/T since I was purely concentrating on getting the launch down.
Originally Posted by 0H8Z06
Nice runs... Still on stock(ish) clutch? lol
Ha! Yes, still stock/original clutch though it only has a little over 5000 miles on it. Once I pulled out the spring it's been flawless since. Previously I would have never been able to hot-lap the car since it (clutch) needed a good cool down. Not any more!
Went 10.94 Friday night in a bone stock zr1 with 19" radials followed by a 11.0 @ 131 but was my first time at the track with this car so couldn't 60' too well. These cars are impressive
Went 10.94 Friday night in a bone stock zr1 with 19" radials followed by a 11.0 @ 131 but was my first time at the track with this car so couldn't 60' too well. These cars are impressive
Very nice --- congrats on the 10's, especially on the first time out! These cars are definitely a challenge to get the launch figured out.
I'm debating going back to the track once more with a few tweaks (race gas tune, namely) before I do the LPE upgrades.
OP what do you call near perfect AF with the stock PE? just curious
All stock with just the tune we had to pull a little out of the stock PE table to get the A/F to 11.7 - 11.9 which is where it was happiest. It believe it was was 11.2 - 11.4 completely stock, IIRC. Not all that bad, really --- not too much room for improvement in the tune, power-wise, without making it knock-prone.
When we gutted the cats the same PE EQ targets resulted in around 12.5; I assume from the increased flow due to the decrease in backpressure. Setting the PE back to the stock values (which EQ of 10.5) put it right at 11.5 which where it ended up the happiest. It didn't make any more power at 11.9; just ended up being more knock-prone with the IAT2's started getting up there, so fattened it back up.
All stock with just the tune we had to pull a little out of the stock PE table to get the A/F to 11.7 - 11.9 which is where it was happiest. It believe it was was 11.2 - 11.4 completely stock, IIRC. Not all that bad, really --- not too much room for improvement in the tune, power-wise, without making it knock-prone.
When we gutted the cats the same PE EQ targets resulted in around 12.5; I assume from the increased flow due to the decrease in backpressure. Setting the PE back to the stock values (which EQ of 10.5) put it right at 11.5 which where it ended up the happiest. It didn't make any more power at 11.9; just ended up being more knock-prone with the IAT2's started getting up there, so fattened it back up.
03-07-2018, 11:58 AM
Back to back 10's in my stock(ish) ZR1
The weather was excellent with the exception of heavy winds that started out as a crosswind and quickly turned to a full-on headwind. 
Up next: LPE710 kit!
