[Z06] 660 RWHP N/A pump gas LS7 H/C/I, now 680 RWHP!
06-25-2013, 10:59 PM
#1
Melting Slicks
Thread Starter
660 RWHP N/A pump gas LS7 H/C/I, now 680 RWHP!
Last Fall my car made 660 RWHP (link to the previous 660 RWHP thread so that I don’t have to repeat all of the build technical engine details ) and now it’s at 680/540 RWHP/RWTQ, still on the factory LS7 short block, 92 octane pump gas, same 257/273 112 LSA solid roller cam, Beck sheetmetal intake and single NW 102mm DBW throttle body……and the exciting news…..there will be more HP to come when I try the P.I. LSX intake in two weeks!!! Here’s the current dyno comparison below:
Peak HP is 680 @ 7300RPM and the motor has an incredible 670+ RWHP from 6800 to 7800 RPM!!! Peak TQ is at ~5900RPM and as you can see, almost table top flat! So much for “peaky” solid roller HP curves.
I finally got the HP/TQ curves smoothed out compared to last time (new plugs and wires) so the real comparison is where I have added 20/20 RWHP/RWTQ over the previous runs. This is why I included a previous 651/520 run along with the 660/501 dyno graph because the car was really making in the 520 range for torque previously but I believe the strange A/F spike at ~4500RPM caused the torque to dramatically dip for some strange reason on this particular run.
It’s too bad that all I had was my i-phone to have this video shot of the car on a typical run on the dyno rollers because the sound of the intake roar is absolutely incredible up to 7900RPM!!!
What did I do different this time? Just as planned, I hand built a set of custom triple stepped headers 1-7/8” to 2” to 2-1/8” w/27” long primaries dumping into 4” merge collectors, 4” dual exhaust/X-pipe, 3-1/2” diameter Magnaflow 12909 mufflers with 3-1/2” tailpipes! This is an upgrade over the 1-3/4” to 1-7/8” stepped headers that had 32” long primaries and 3-1/2” exhaust/X-pipe and 3” DynoMax mufflers and 3” tailpipes. And believe it or not, the car is even quieter than it was before…can you say ultimate sleeper!
Here are some pic’s of the headers and exhaust:
I still plan to try the Performance Induction LSX aluminum intake with my DBW NW 102mm TB on top to see if I can crack 700 RWHP…it should be REAL close! The bad news for readers is that I will be on vacation and not back in town until after the 4th of July so the intake swap will just have to keep both you and me in suspense!
To say that I am excited about this set-up now is beyond an understatement given the fact that I believe this motor combo is likely to be the most powerful N/A single DBW TB, factory stock shortblock running 92 octane pump gas LS7 on the planet….woohoo!!!
And yes, when I am finished dyno-ing the car I will find time to take it to the track since I know there are many doubting Thomas’s about this car questioning how real and repeatable the power may really be….well take a look below…..how does EIGHT back to back runs of 679+RWHP rate for consistency? The two runs topping over 680 have a minor HP spike at the end of their run due to the rev limiter kicking in so I didn’t count these as my max power runs but before the spikes…679+!
And once again I’d like to thank Steve Barker (632C2 on the Corvette Forum) for having my car on his dyno for all of the trials, tuning and R&D work, THANKS Steve!
Peak HP is 680 @ 7300RPM and the motor has an incredible 670+ RWHP from 6800 to 7800 RPM!!! Peak TQ is at ~5900RPM and as you can see, almost table top flat! So much for “peaky” solid roller HP curves.
I finally got the HP/TQ curves smoothed out compared to last time (new plugs and wires) so the real comparison is where I have added 20/20 RWHP/RWTQ over the previous runs. This is why I included a previous 651/520 run along with the 660/501 dyno graph because the car was really making in the 520 range for torque previously but I believe the strange A/F spike at ~4500RPM caused the torque to dramatically dip for some strange reason on this particular run.
It’s too bad that all I had was my i-phone to have this video shot of the car on a typical run on the dyno rollers because the sound of the intake roar is absolutely incredible up to 7900RPM!!!
What did I do different this time? Just as planned, I hand built a set of custom triple stepped headers 1-7/8” to 2” to 2-1/8” w/27” long primaries dumping into 4” merge collectors, 4” dual exhaust/X-pipe, 3-1/2” diameter Magnaflow 12909 mufflers with 3-1/2” tailpipes! This is an upgrade over the 1-3/4” to 1-7/8” stepped headers that had 32” long primaries and 3-1/2” exhaust/X-pipe and 3” DynoMax mufflers and 3” tailpipes. And believe it or not, the car is even quieter than it was before…can you say ultimate sleeper!
Here are some pic’s of the headers and exhaust:
I still plan to try the Performance Induction LSX aluminum intake with my DBW NW 102mm TB on top to see if I can crack 700 RWHP…it should be REAL close! The bad news for readers is that I will be on vacation and not back in town until after the 4th of July so the intake swap will just have to keep both you and me in suspense!
To say that I am excited about this set-up now is beyond an understatement given the fact that I believe this motor combo is likely to be the most powerful N/A single DBW TB, factory stock shortblock running 92 octane pump gas LS7 on the planet….woohoo!!!
And yes, when I am finished dyno-ing the car I will find time to take it to the track since I know there are many doubting Thomas’s about this car questioning how real and repeatable the power may really be….well take a look below…..how does EIGHT back to back runs of 679+RWHP rate for consistency? The two runs topping over 680 have a minor HP spike at the end of their run due to the rev limiter kicking in so I didn’t count these as my max power runs but before the spikes…679+!
And once again I’d like to thank Steve Barker (632C2 on the Corvette Forum) for having my car on his dyno for all of the trials, tuning and R&D work, THANKS Steve!
06-26-2013, 08:39 AM
#4
Le Mans Master
Member Since: Nov 2005
Location: Kendall Park NJ
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Beautiful build. 
Do you have any concern with the OEM rod bolts or have they been changed over? The stock LS7 bottom ends are great; however, I personally would feel more confident with better rod bolts near or slightly above 8,000 rpm depending on shift points.
BTW- I agree that this car will really shine at the track.
Good luck and keep us posted.
Do you have any concern with the OEM rod bolts or have they been changed over? The stock LS7 bottom ends are great; however, I personally would feel more confident with better rod bolts near or slightly above 8,000 rpm depending on shift points. BTW- I agree that this car will really shine at the track.
Good luck and keep us posted.
06-26-2013, 07:27 PM
#5
Melting Slicks
Thread Starter
Thanks for the feedback guys!
Actually I have a greater concern using the factory cast pistons....the rod bolts are still stock. Just another reason why at the track I really don't want to spin the motor past about 7700/7800 RPM.
Do you have any concern with the OEM rod bolts or have they been changed over?
Last edited by JMB; 06-26-2013 at 08:17 PM.
06-27-2013, 11:33 AM
#10
Congrats..what a Beast...here come the "chicken Littles"
06-27-2013, 11:35 AM
#11
Safety Car
06-27-2013, 12:58 PM
#12
Melting Slicks
I keep seeing threads about boosting the power on these motors. Then I read that you really shouldn't. I just traded my 2011 Camaro SS that was supercharged and had all the other bolt on ****. My salesman called me yesterday and tells me that they had a older guy come in and test drive it and blew the motor up. I'm afraid to do anything to my motor on this one. Help me out here guys. I really want more power but don't want to buy a new motor.
06-27-2013, 01:51 PM
#13
Le Mans Master
Wow. That is insane power for N/A and pump gas. Very nice!
07-13-2013, 09:56 PM
#14
Melting Slicks
Thread Starter
For those subscribed for an update with the LSX intake (which added 10 RWHP more) please click here http://forums.corvetteforum.com/c6-z...post1584400394
