Yellow Bullet Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
343 Posts
Discussion Starter #1
What size shot have you guys been hitting stock bottom end LS7s? Have a buddy that is putting spray on his heads/cam Z06 and wants to hit it with a 200 off a 102 plate. Assuming a B8efs plug with C16 in the dedicated will it take the hit with a good tune up? Car made 570 NA.
 

·
Registered
Joined
·
2,034 Posts
I wouldn't spray it at all if it were mine, its a ticking time bomb already lol
 

·
Registered
Joined
·
561 Posts
The sleeves are brittle. Nitrous makes a lot
Of cylinder pressure and you risk cracking a sleeve before hurting anything else.
 

·
Registered
Joined
·
561 Posts
Texas mile car I built in 08 had a callies rotating assembly, and stock heads/block. 22 psi was as high as I pushed that setup. Made 1080 rwhp and went 210. Timing was very low, however. 16/18* on Q16 and meth. Probably another 100 hp in that tune up, or more. It would go over the chart rich as voltage went down. that was before the days of correct data and ID2000s.

Rodney RPM, his yellow Z that Cameron raced at LS fest has a D1, ran
Bottom 9s in good air, I think that's around 15psi. Totally stock short iirc.
 

·
Registered
Joined
·
64 Posts
A buddy of mine did a 250 direct port back in 09. Even at 12* or timing on race fuel it lasted only a short while. 740rw. IIRC that motor split a sleeve. If that doesn't happen you'll drop a stock exhaust valve. When it came out, one exhaust valve was stretched almost .200 longer than stock, and would have dropped very soon killing more than just the sleeve.
 

·
Registered
Joined
·
23 Posts
A buddy of mine did a 250 direct port back in 09. Even at 12* or timing on race fuel it lasted only a short while. 740rw. IIRC that motor split a sleeve. If that doesn't happen you'll drop a stock exhaust valve. When it came out, one exhaust valve was stretched almost .200 longer than stock, and would have dropped very soon killing more than just the sleeve.
Are you thinking about my Z06?

The engine you're thinking about was my 'spare' engine that I had in the car for a short while. It was a heads/cam setup with 200hp pills in a direct port (the stand alone fuel system had MS109 in it). It made 585rwhp on the motor. During the first test hit on the street with the nitrous the logs looked perfect. It was on decel that the nitrous controller activated on it's own for a split second and killed the engine. Four liners were split. During teardown I did find a stock exhaust valve that was .050 long and about to drop.

The original engine went back into the car and I set it up with the 250hp direct port kit. It made 732rwhp with headers, cold air kit and 14* of timing...completely stock long block. Eventually I removed the fogger and set it up to spray a wet & dry dual stage that totals 250rwhp. The engine is still alive and kicking today.

The limit of how big of a shot you can reliably run on an LS7 depends on the current mechanical state of the engine and your tuning abilities. Understand that an LS7 will not tolerate any mishaps. There is zero room for error.

At any horsepower level an improperly tuned nitrous kit can and will kill any engine. This is especially rings true in reference to an LS7.
 

·
Registered
Joined
·
343 Posts
Discussion Starter #13
Are you thinking about my Z06?

The engine you're thinking about was my 'spare' engine that I had in the car for a short while. It was a heads/cam setup with 200hp pills in a direct port (the stand alone fuel system had MS109 in it). It made 585rwhp on the motor. During the first test hit on the street with the nitrous the logs looked perfect. It was on decel that the nitrous controller activated on it's own for a split second and killed the engine. Four liners were split. During teardown I did find a stock exhaust valve that was .050 long and about to drop.

The original engine went back into the car and I set it up with the 250hp direct port kit. It made 732rwhp with headers, cold air kit and 14* of timing...completely stock long block. Eventually I removed the fogger and set it up to spray a wet & dry dual stage that totals 250rwhp. The engine is still alive and kicking today.

The limit of how big of a shot you can reliably run on an LS7 depends on the current mechanical state of the engine and your tuning abilities. Understand that an LS7 will not tolerate any mishaps. There is zero room for error.

At any horsepower level an improperly tuned nitrous kit can and will kill any engine. This is especially rings true in reference to an LS7.
what fuel in the main tank? what plugs? thanks for the info.
 

·
LSXTTFMF
Joined
·
927 Posts
Yeah def have to watch the cylinder pressure and keep all detonation out. I truly believe the piston ring land will let go before the sleeve will from HP. Detonation will take out both. From what I've seen when you get a ring land it swells/wedges into the cylinder and cracks the sleeve too. I've sprayed up to a 150 shot on completely stock bottom ends and ran up to 10psi on a bottom end on purely 93 octane alone but like said its a ticking time bomb. I don't suggest it to anyone and only tune them if the owner knows that its not gonna last long doing it.
 

·
Registered
Joined
·
64 Posts

·
Registered
Joined
·
343 Posts
Discussion Starter #16
we hit it with a 150 and it pulled hard and very clean. only did a 3rd to 4th gear pull so i really couldnt get a good fuel ring on the plug. car had a BR7ef gapped at .035, 18 degrees of timing, C16 in the stand alone with 55 psi, 2 gallons of MS109 and 3 gallons of 91 in the main tank, and 62N/31F jets. It read 11.8-11.9 through the pull on the wideband. going to take it to the track this weekend to see what she runs.
 

·
Registered
Joined
·
750 Posts
It wouldnt hurt it to fatten it up .5 and start at 15 degrees and run 100% 109 in the tank, Be safe and good luck !
 
1 - 17 of 17 Posts
Top