TWS

iTrader: (63)

After running around with the ridiculous original 6 rib pulley setup on my Procharger kit for years, just a couple months ago I finally coughed up the $ and got the 8 rib conversion and installed it. I went with the 4.50" blower pulley. My original 6 rib kit was good for 8 psi, when it didn't slip. I went out a couple weeks ago with a race gas/Shell 93 blend in the tank and did some research to find out what my new setup is doing... 10 psi. With the race gas acting as a safety device, I did not hear any knock during two initial highway pulls performed to verify boost. I thought the 4.50" pulley would keep my peak boost at 8 psi... probably needed the 4.63 pulley to do that. Anyway, the higher boost and much better belt wrap feels really good.


Fast forward to this past Saturday night. I linked up with a buddy and we hooked up his laptop and data logged. Possibly due to slightly different weather and probably due to my race gas now being 2 weeks old... the motor showed knock from 4800 rpm on up. To just throw a quick band aid on there, we added 6% fuel and took out 1* of timing (down from 18* to 17* now) from 4800 on up. My stock MAF is pegged, so an 85mm is on it's way. We plan to load the appropriate MAF tables and do a complete retune on the dyno once the new MAF is on. We'll see what A/F it likes to make power and keep it out of detonation. Probably 11.5-ish, but we'll see what it wants to do.

Anyway, my question for the community is, who is running 10 psi or more on a completely stock LS1 and what did you do to try and ensure the motor will live?

Thanks!

black98ws6ta

iTrader: (77)

95% of the people will tell you a good tune. A centrifical supercharger is alot easier on the motor since it does not make as much boost down low. Make sure the car has a wideband and always keep an eye on it. Methanol injection would help. I have run as much as 15 psi on my stock ls1 with 6.0l heads, cam, and e85.

Aster

iTrader: (9)

Didn't you just get through having problems with different MAF's on the red car?

Honestly, ditch the MAF and get an SD tune. That way the computer won't ever be blind and you won't have to fight the MAF tuning for a bigger sensor. That and a 2 bar MAP can be had on the cheap from our friendly neighborhood parts supplier.

Seriously though if you tuned the car with the current MAF in the cold and kept it safe, don't try and squeeze all the power out of it, you'd probably be ok that way. Just don't ever change anything without an immediate retune.

LS1 SPEED

iTrader: (22)

I agree to ditch the MAF and with proper tuning you should have no issues.

good luck

conan

iTrader: (5)

https://ls1tech.com/forums/forced-in...lity-list.html

shawn_c992001

I am. With meth of course, and not all the time.

1BAD_LS1

iTrader: (36)

First off, get fid of that MAF.... go SD and never look back....

had the sts kit a 9psi and it didn't last long..... it was stock heads and shortblock with aftermarket cam, springs, pushrods.....

I ran 6psi for a few months then bumped it up to 9psi and killed #7 ringland about 2 weeks later!!!! I wouldn't do it, ive already learned my lesson....

well maybee not, i am running 14psi on a stock shortblock 5.3 LMFAO! But my compression is only 8.5:1 with the 317 heads so its alot safer than the 9psi on the stock compression ls1....

TWS

iTrader: (63)

I guess you didn't pay any attention to what I did with the red car or how it turned out. But since you brought it up, I am doing to this car exactly what fixed the problem on the red car. The 75mm MAF was pegged and I swapped in a larger (85mm ZO6 MAF), changed the MAF tables, retuned the PCM and problem was solved. Same situation exists with this car, and we are pretty confident the same solution will work just as well the second time around.

We debated going SD on the red car and ultimately decided against it. With the pewter car we're going to aim again at a safe PCM tune. I'm not interested in grasping for the last 5 RWHP, I'm interested in keeping it all in one piece.

Anyway, that wasn't the purpose of this thread. I wasn't looking for input on the MAF situation, unless ditching the MAF and going SD is what some people really think is the key to safety - (and my tuner doesn't think so himself). I'm looking for folks who have run 10 psi on a completely stock LS1 and see how they fared.

Looks like Conan posted a link to some good data. I was also looking for some anecdotes/testimonials from guys in my situation.

Aster

iTrader: (9)

Cool, I couldn't remember exactly how you fixed the MAF on the other car, and you should be good there for where squeeky is sitting. I think 10 psi is heavy but some people last a long time with it. I remember the stock bottom end reliability list, it seems so hit and miss with these cars. Besides given how you treat it you should be ok for a little while, but you're on the very edge man.

TWS

iTrader: (63)

Damn. That's not encouraging. BTW, my Vortech car has run 9 psi for nearly 12K miles and that includes a decent number of all-out highway bombs. It's not a track car, but it does see some late night exercise on the highway. It has a completely stock LS1 motor too.

TWS

iTrader: (63)

Yeah, I am concerned with the jump from 8 to 10 psi that the new pullies caused (thus this thread). Can't agree more with the idea of an immediate retune, which is why I had Blacker datalog and look at it as soon as we could possibly meet up. I want to be one of those guys who makes a positive report on reliability, not a negative one. 10 psi strikes me as dicey, but I don't have any experience pushing a stock LS1 like that. So... I don't know what I don't know and am trying not to learn the hard way. The fate of your original stock motor weighs heavily in my mind.

1BAD_LS1

iTrader: (36)

I forgot to mention about 95% of the time i drive my car i beat the hell out of it.... Im guessing i was at around 700hp+, because i was about 420hp NA....

In my opinion its not really the amount of boost you run its the amount of power your making..... 550-600HP seems to be about the limmit, anything more and your just asking for trouble....

OreoLt1

iTrader: (11)

Been running 5-6 psi min. and 10-11 psi max for the last few years( est. 30K mi) on a stock ls1. Have not had an issue at all untill just recently when a coupler blew and somehow related pushed oil out the dipstick a few days later when shutting the eng. off. But still have OE and STS pcv!

Aster

iTrader: (9)

Yeah, but at least you had the presence of mind to run the race gas. I didn't hence the earth shattering kaboom. I guess all you can do is run it as safe as you can and go from there.

TWS

iTrader: (63)

Very useful thread. Thanks!

It's encouraging to see a number of guys running 9-11psi for a good long time on stock motors and making good power. However, it does seem hit or miss. I would bet that some of the "unlucky" ones just didn't have a good accurate, safe tune. That thread seems to support black98ws6ta.

TWS

iTrader: (63)

Well, truth be told... I was scared. I just piddled around town until the low fuel light was on, put in three fresh gallons of Shell 93 and one fresh gallon of MS109 that I had bought the night before. I didn't dare drop the hammer until then.

I can't afford a motor for this car now nor anytime soon. If I screw up, the car is going to have to sit broken and that would suck.

TWS

iTrader: (63)

LMAO. You are like a lot of my local buddies.

I actually drive petty conservatively unless I am deliberately testing something, or if I hear three honks. Sometimes I'll do a little part throttle pull to put a grin on my face, but I'm not running the gears until the shift light. Just a little push back in the seat to remind me why I have the car.

There's been a lot of back and forth about a particular horse power number that a stock LS1 can handle. I am going to find out what it puts down on the Dyno Jet fairly soon, but the old butt dyno says maybe a little over 500 RWHP. It did 479 RWHP on 8 psi, but hasn't been on a dyno in years.

TWS

iTrader: (63)

Thanks Larry. I know you and Aster and respect both of your input. I'll talk to my tuner again about SD. We weighed the pros and cons with the other car, but I'll bring up the topic again.

sujomatt

iTrader: (7)

Ive been running 10psi for some time.. About to raise it to 11-12 (Just added a big shot of Meth).. On stock bottom LS1, 317 heads. Knock on wood things continue to go well.

TWS

iTrader: (63)

Good luck Matt. My static compression is higher since I have stock heads vs. your 317's, but it's good to know you have had success.

560/589 @ 10psi is impressive. Mine is definitely not making that much, but I don't have an FI cam like you do, and it's a different type of FI alltogether, but still interesting to see your power level.

We are going to go conservative on the timing and a little rich on the A/F. I think I will get in the habit of putting some MS109 in to blend with the 93 anytime I think I'll be romping on the throttle.