OK, I've been around here for awhile, but what is the max safe boost level one can run with a P1 and Alky injection?
I know quicksilver02 is running 10-12psi with a stock bottom end, but I have a 98.
And I know the rod bolts are different!

 

The main concern is the pistons, the rod bolts really aren't an issue.
We try to keep them around 8 lbs. You can go higher as long as you understand that your on the edge.

 

Doug,
What about on the Z06 (higher rev limits) under boost, say 650 rwhp @ 6500 rpm? Are the rod bolts still not much of an issue? At what RPM / RWHP do you worry about the rod bolts assuming the pistons stay glued together???

 

So with AI can you safely run more than 8 lbs of boost or can you just add more timing? (BTW, I've been running 9.5 - 11.5 lbs of boost from day one). Hmmmm.

Mark

 

I remember Rob Raymer running quite a bit over 700 rwhp on a 120,000 mile STOCK LS1 with only upgraded valve springs while using the alky, so it can be done. ECS is a good company to listen to, as they seem to have a good bit of knowledge, along with Julio. Best of Luck to you!

 

LuvmyC5 are you running Alky? If so who did the Tunning for you?

 

There are plenty of H/C cars that run 7200 rpm without rod bolt issues.
F/I or not the rod bolts do not get stressed untill the piston comes back down. Primarily on the intake stroke when the piston does not have any down force on it from compression. Excessive boost will stress the rod itself not the bolts.
I have never had a rod bolt issue yet in an LS1, granted any engine built here has ARP bolts, but as far as stock engines go no issues.
We have seen a ton of broken ring glands, we have even seen an over boosted stock engine bend every rod in the motor like an s. Even then the rod bolts were still good.

Point being, your pistons will let loose way before the rod bolts. (there is always an exception)

 

Think '01+ stock rod bolts were improved.

 

Thanks Doug.... one less thing to have nightmares about tonight!

When the pistons go is it mostly because detonation (lack of fuel / octane)?

 

Thanks Doug.... one less thing to have nightmares about tonight!

When the pistons go is it mostly because detonation (lack of fuel / octane)?

 

Remember, too, that boost has less to do with it than the actual cylinder pressure under combustion (power) that the engine actually makes.
Boost is only the pressure left in the intake manifold from the air the motor couldn't ingest. A motor with a tiny cam, restrictive intake, weak cylinder heads and a poorly designed exhaust might make 14# of boost and make only 300 HP. That motor isn't going to hurt itself.
The same motor and blower with a well designed blower cam, free flowing intake, heads and exhaust might have only 8# and make 600 HP. Less boost but much more air being ingested by the engine. Which motor is more likely to break a piston?
The perfect scenerio would be to have an engine with a perfect intake, head , cam etc. that made absolutely NO boost. ( Of course this is impossible) An engine that could ingest all the air the blower could put out might make 1200 HP. ( Probably much more) Now we have a motor with no boost. Now which motor would you expect to blow itself to pieces? Makes you think, doesn't it?
My theory is to use a smaller blower, spool it faster and tune it way down at the top. I have cars that make over 500 RWHP that only have 12 degrees of timing. That way they make better mid range power, come on sooner and still don't kill themselves up top.
I see guys installing my system and making 600 RWHP. That's fun for a while.... I usually make around 550-575 on a Z06 and then tune it down to 500 - 525. That's pretty good for a street machine.
Boost is only a number. There's MUCH more that goes into making a sucessful combination.
Just my opinion, for what it's worth.

 

OK, so listening to the 2 best FI tuners in the country it sounds like I should be able to keep it together as long as I don't run lean or run to much timing up to 6500 rpm.

Currently I am limited to 6100 rpm because of a 3.6 inch pulley that makes me 8.2 lbs of boost.
I agree with Andy it is nice since it comes on strong earlier then when I had the 3.85 pulley. I am also running a consertive tune with only 17 deg. of timing with an 11.7 AF. What I would like to do is just increase the RPM's another 3-400 and keep the timing and AF.
I know the pulse width will need to be turned down on the injectors because I have added the alky setup. And I will be running pure M1
per Dougs recommendition with 93 octane fuel.

The other question I have is where to get it tuned? Last year I had it done at APE in Clinton Township Mi. but at some point I will be moving to Fla. this summer.
APE uses a Mustang dyno and Norris in Orlando uses a Dyno Jet, I'm really looking for the best of both worlds, but is the air significantly different in Fla?
At least if it's tuned here it's apples to apples.

 

Make sense to me! Thanks Andy

 

Makes sense to me! Thanks Andy

 

Nope, not on this car, but I had 2 87 GN's that had it on them. They were tuned by burning a chip (old school stuff), so I'm sorry that I'm no help to you.

 

Correct

 

So.....
Given enough fuel and octane so that detonation is not an issue, how much power can the factory short block take and what will let go first? I know everyone said the stock bottom end can't take over 600 rwhp, but many of us have seen these levels w/o failure for sometime now so I question this theory. As I recall Rob R. was over 700 rwhp on the stock short block and he really ran that thing hard. Does anyone really know at what point the sky falls with a good tune and plenty of octane???

 

So if you could eliminate detonation (say by using Alky) what are the next weakest links and in what order would things begin to fail if you pushed too much HP on a stock LS6?

 

Anyone?

 

ttt