just for bryans info i have pushed a 4.8 and a 6.0 and a 408 each to the limit of pump gas. i varied timing and fuel from one extreme to the other. my experience has been in line with what other members here post.

Blue, i ran a simple log style header here is a pic.



then upgraded to this header set up and a larger down pipe.



with both of those headers it seems the turbo was my limiting factor, i made the same hp with both headers. this is just my oponion but i dont think the hot parts make all that much difference under 1000fwhp.

 

is that the 408motor in ur truck now parish?

 

I have run a stock LS1 (10.1:1 compression) in cool weather with no alky on 91 octane at 10.5 psi and make a little over 500 rwhp. It's summer now so I have added alcohol for extra safety in the 110+ temps. 10.5 psi was not my limit on 91 octane in sub 80 degree weather. I had it all the way upto 12 psi but backed off 2 psi for some safety.

During 105+ days I have seen 13 psi with the alky and no knock, but it's on the edge of detonation. When i run a 50/50 mix of 100 and 91 I've bumped the timing 3 degrees over the entire range and have seen zero increase in knock.

Running the turbo on my car has been a real eye opener as to what a high compression motor can take boost wise with just good tuning. 7000 miles at 10+ psi and counting!. Motor just turned over 71,000 miles.

Tuning is the #1 key to having it last. Do not let it run lean. I run my motor at 11.0:1 a/f to make sure I don't run into a lean cyl problem.

 

yes, runs good too

 

i made 900 rwhp pump gas with 363 cubes through a c-6 runing 21-22 psi i also ran 8s and never once blew anything except for when my fuel pump went out at half track and fuel preasure fell to 20 psi. .. but that would have blown any setup that was FI

it can be done if you do it right end of story.

however usieng high compresion like the above fool it will never happen on pump gas

you MUST run aprox 8.5-1 to 8.2-1 compresion use a piston that has a dish that is a mirror of your combustion chamber and you can do it period with the right cam selection and tuneing.

i drove my car everywhere and ran probly 50 low 9 second passes and a couple of 8s with it on pure chevron 93 octane.

now that said i turned my timeng and boost up and i just made 1089 rwhp through taht same c-6 at 29 psi

 

how many names do you post with? if you stick with one and it will be easier to know who we are talking to.

 

if i cranked my boost on the dyno till i **** out a head gasket i am sure i could get better numbers. my tuning is mostly based on my knock sensors, when i see knock i consider that the limit of the fuel and back off. i have not spent hours and hours on the dyno trying to get to a number but i have spent many hours on the street and track tuning to the edge of knock. a 5sec dyno pull means very little to me.

I can not get anywhere near the numbers on pump gas that you are geting. most other people here can't get close either. maybe you know some special tricks or maybe you are full of BS, doesn't really matter. what does matter is you telling other members that they can do it and the 99% of the rest of us that cant do it are idiots that dont know how to tune.

Blue can look at the accomplishments of the people posting in this thread and decide who he wants to listen too.

 

from what im gathering from all you uber pump gas fiends heres what it comes down to:
1) it can be done on a stock shortblock,but not for forever and your better off saving for a forged 1 and make money off your good condition stock 1
2) tuning is a NECESSITY for making those types of power figures
3) when you have a large bank account you can do whatever the hell you want.
4) You can make high hp #s on a stock shortblock or a forged SB,but a forged 1 will go the distance in the long run.
5)get back on topic seeing as how he doesnt have all the money in the world and is using a stock SB and an STS kit.
we'll there you go,lets see what he puts out and for how long.

 

just becuase you did it ONCE on a CHASIS DYNO means NOTHING

the diference between a chasis dyno and the real world is HUGE your performance numbers you have put up say you'r car makes no where near that kind of power real world.

also you say it nver detonated i call bullshit becuase YOU DONT BLOW A HEADGASKET unles you detonate period

i have made 1000 horsepower with STOCK ford 302 head gaskets and had them never blow its the SPIKE in cylinder preasure from detonation that causes them to blow.

a motor that has never detonated will not blow a head gaskest unles its from warping of the deck surface over time or from head bolt stretch simple as that.

as was said here before i dont care if you like me love me or disagree with me but your method is idiocy you will blow your junk up trying to make that kind of power that way as you clearly have shown.
how many head gaskets have you replaced how many times has it broken ?

one dyno pull that may or may not be real is NOT any method to show what a car makes take it to the track the mph will show the power PERIOD you can not argue with the mph of the slip and if your not making the power you wont run the mph and clearly you are not runing the mph for the power you claim..

so ill go with listening to people who do this for a living like me instead of a message board jokey.

oh and if you blew a cometic gasket you detonated or you didnt install/finish the deck corectly PERIOD i make over 1600 horsepower with my shop race car that has 4 head bolts per cylinder IE a ford and have never EVER blown one as we dont tune it on the raged edge.

in fact i have NEVER seen a cometic head gasket fail unless there was severe detonation .. same goes with the supra guys who run 30-40 psi on race gas and cometics.

your post saying we didnt see any detonation lol that alone shows your clueless short term detoantion that will KILL a head gasket doesnt show on the rod bearings as its a very SHORT event its smaller repeated detonation strikes that start to show on the bearing over longer periods of time. .

at the levels you are talking about detonation will take the head gasket out imediatly and not have time to do anything to the rod bearing. unles your to stupid to feel the car lay over and you stay in it.

 

Dean (?)...

Care to elaborate on cam specs? Rule of thumb?

 

How about this...raptor/Brian, please prove to us that your combo is safe (even though you blow head gaskets) and proven (even though you have never tuned or run the car really anywhere at that level but on a Dynojet).

You can prove it by either a) taking it to the track and putting real load on the motor...or b) putting it on a real load dyno (Mustang or SuperFlow-style) and dial in your weight to produce real-world load.

Hell...I'll go out on a limb and say that you will hit 1100rw on 93. Big deal....problem is, it will be on a dynojet dyno with detonation and at least 1 blown head gasket.

 

Well at this point it is probably a mute point as I have taken the motor down, and opted for a lower compression piston to reach my goal. Perhaps you are right about the gasket. The gasket that I pulled out was in perfect shape. The cause for the problem was a result in the heads lifting. From my understanding it is a problem with the LS6 head not having a thick enough deck, that will be resolved with the new casting. You may be right again, that the only way to prove that this is possible is to take the car to the track. I am curious, did you make your runs at the track with 93 Octane. I mean that is what you are claiming. If everyone else who is curious chooses to believe that it cannot be done, so be it, dont do it.

What you havnt done is make 1000hp on pump gas at 10.1 CR. That was what this is all about. I feel pretty certain, with 8.0 CR that is a no brainer, which I believe what you and Phish8 are saying. I have never doubted that.

Again we will just go with I dont know what I am doing, and have no clue as you said.

 

Parish8,
I am curious if you tried any diffrent turbine housings with your setup, alot of the time that is what is the limiting factor as the smaller housing cannot keep up with the flow (I am sure you allready know this, just curious if you tried).

-Bryan

 

Bryan, This Dean guy has actually run at the Hot Rod Pump Gas Drags. They run on 93 pump gas. Dean, how heavy is your 95?

 

Bryan I heard a rumor you dropped a cylinder liner in the 427

 

um yes i ran 8.91 at 160.8 mph on chevron 93 octane at 3440 pounds do the math that is right what i should run at my weight for the rwhp numbers i make.

 

???????????????$$$$$$$$$$$$$$$$

 

the only turbo i tried was the q trim t76 with .96 ar. we thought about trying a gts t76 or what ever that 76 is with a higher rating but decided to just jump up to a pt88. i have gathered some experience with the t76 on several motors but have only used that one turbo.

 

The 76GTS will make an additional 200hp over a Q-trim. As for the 88 and 76GTS, we saw 25rwhp extra with the 88 over the 76GTS at 24psi. Not much, and the 88 made 20 less rwtq though. On a 408 though, those #'s would be somewhat difference since we aren't taking into account the 76's backpressure rise on a 408.

 

I overheard him telling a buddy of mine at a shop in raleigh today that he had dropped a cylinder liner.