IMO

Due to this being the 2nd time this has happened, I am going to guess that I have reach the limit of how much boost can be thrown at a 10:1 compression LS1 setup. Today that was 18.6psi. The air/fuel curve looked sorta ok, and at 5200 RPM the max power was 816RWHP and 767FTTQ. That is where we let off of it because it was so started to run so rich, So much for the 800HP limit of the 71# injectors. The HP Tuners Dongle that was sent off to be fixed came back and still does not function, so I could not tune anything. We were going to make another run and that is when Mr Gasket said, IM DONE. This is also the limit of the commetic MLS gasket with 10:1 compression.

Luckily it happened just when we started the car, Intake temp was 130 and boost was 18.6. 93 Oct.

So what have I learned.

This is not the power limit on straight pump gas. This is the limit of 10:1 compression. Static has to be in the 18-22 range.

Throwing race gas at this would not have made any difference other than allowing me to rase the timing and possibly having a little more power.

I am done for now, until I opt for a lower compression piston and a stronger rod next year, I am just going to replace the gasket and run it at the 14.5PSI level.

 

What sort if timing was it taking with 18psi and such high CR ?

 

Yes Yes - Please tell us? I am inyrested to know also!

 

I'm assuming this was done on a dyno? If so, what kind of dyno was it? Thanks

 

And is this still with a single A1000 pump ??

 

still pretty good numbers. Are you still going to that HPP shootout?

 

It had a decent AF (?), it was rich, and it blew a head gasket?

What was the AF?

If I were you I would at least play with methanol injection if you have lost a head gasket twice... Making track passes will be like losing a headgasket while driving the car at WOT.

 

19 degrees

 

dynojet

 

bryan,
what about using meth like john said, but only at the track, just as some added insurance. NOT on the street, so you would still have your street HP claim, just when you go to the track add a lil meth on top to ensure the gaskets stay where they are

 

When it started into its run, it was above 11 but below 12
It Maintained that until about 5000 and headed south(rich) The curve would indicate that it would prefer 12.5 A/F after 4800rpm. Every engine is different. Only time will tell.

The blower made 14.5 PSI with the inlet tube and filter on the F1-R and 18.6 with it off. That is where the gasket said bye bye.

I am thinking about other options to cool the charge other than adding somthing to the intake stream.
I am 100% certain that with a little lower compression like what my new pistons have, I will be able to hit 20-24psi, and still be on pump gas. Try and understand, I have to do this for no other reason because everyone says it cant be done.

just like it was said 71# injectors would not be able to deliver enough fuel and by the way, they are in the low 80% DC range.
just like it was said that you could not make 800RWHP on pump gas, and by the way, I make 800RWHP on 14.5PSI at 6000, and it will run all day.
just like it was said the A1000 could not deliver enough fuel to supply more than 800RWHP on a blown application.

Now John, I know you did not say all these things, but you should know me well enough now, to know that I dont play around. I will hit the 1000 RWHP mark with this LS1 motor, and it will run reliably on 93 Octane.

As Always your friend
Bryan

 

Yes,
The key to making all of this work with the 71# injectors is really big fuel lines.

 

have you ever had a problem with the A1000 running in the dead of summer? Alot of guys here by me (texas) have problems with them in the summer, it moves the fuel too fast and heat it up too much and it doesnt work well

you have any problems, also is yours mounted in tank or out?
Thanks
ed

 

I have had some simular problem if the car idles way too long, but there is a solution. Aeromotive makes a voltage regulator that steps the voltage down and slows the fuel down at lower rpms and steps it back up at upper rpms.

Mine is mounted outside of the tank, incase I needed to service it.

Hope that helps
Bryan

 

I know about the voltage regulator, just seems like alot of cash for a fuel pump, hopefully I wont have to switch over to that kind of a setup, I had one once, but I got rid of it, I was hoping the twin 255's would work
I still think it may
ed

 

I'm by no means an expert on the matter, but how on earth do you run so much timing ??
Uve recently only got mine running, and spec is almost std albeit with a YSi + 9psi, and mine wont take any more than about 13 deg.
Though UK fuel isnt as good as US fuel, but not by that much.

If I though I could safely run 12psi or so with the stock LS1 engine, I'd give it a go. Id say that if I did try it, I'd end up having virtually zero timing advance.
My AFR's are in the low 11's and charge air temps no more than 2-3 degC above ambient when on the move.

 

Bryan, have you thought about dropping your c/r? or will that only happen when it's time to freshen the motor? you're doing a killer job and getting some serious #'s out of that beast. can't wait to see even bigger power levels if you do.

 

I will be doing a piston/Rod swap sometime this winter, I purchased JE pistons with a 9.5.1 CR and 6.125 Oliver Rods.

I only want to hit 1100RWHP and do it on this motor with 93 Octane without adders. Once I have accomplished that I will back the boost back down.

 

Intake air temp and A/F is the key. I would guess your air intake numbers are higher than what you are seeing. That is the only thing I could guess.

I could post my VE and timing table if anyone was interested.

The only other thing is have you noticed what your fuel pressure is at WOT. Are you running out of fuel?, With only 12psi I would think I could run the timing up to about 22 degrees, not 13.

I did notice in your signature about your dual exhaust and can tell you, that even though you would not think so, a single 3.5" will outflow the duals.

 

Mines a speed density setup. When I first got it running with boost, I had the timing up closer to 18deg at that part of the map, and it was pinking like mad. I had to drop it back to kill the det. I would be getting about 18 deg in the midrange, but boost pressure then is only about 3psi climbing
Im not monitoring fuel pressure, but see no reason why it would be an issue. AFR's are steady in the low 11's. I could easily drop them to 10's if I wanted ( and had done during setting up ), or lean them off. Keeping them in the 11's for safety.
A1000 feeding 1/2" solid alu pipe feeding the Aeromotive rails via a fuel dist block.

Charge air temps are measured in the pipework just before the TB, and I have no reason to doubt their accuracy.
Exhausts are 3" collectors, stepping down to 2 1/2" with a balance pipe between them on the 2.5" section. 2 x 2 1/2" Magnaflow straight through silencers.
Eventually I will swap to 3" from headers to exit.

What sort of timing are other 10:1 CR pump fuel only, boosted motors using ?

can you plot a table of map vs rpm for timing ? The ve tables on the stock ecu dont mean that much to me.