How much boost on stock block w/strim.

[BlueOvalStangGT]

Hey im running around 10 right now, and I want to have it around 13-14 I think. Is this reasonable for an s-trim and a stock block with stock internals? Im going for a dyno Saturday so I was thinking over night a pulley so I can tune it with the new pulley? Think 13#'s is ok? Maybe in the future run water meth if I can get soem good reviews? Would I need another tune if I got the water injection after?

 

[Rootus]

It's not about how much boost you run ... I know people who run 18+ PSI on the stock block ... it's how much power you're making. IMO, for high reliability, 450 rwhp, 500 will probably be fine for quite a while, 550+ and you're living on borrowed time, even with a good tune.

 

[Joe 5.0]

18 psi on stock pistons seems like a little far-fetched, but wtf do I know.

If 18psi is safe why do companies only offer 6-8psi as safe?

 

[Rootus]

18 psi on stock pistons seems like a little far-fetched, but wtf do I know.

Not everything, apparently . Join the club...

If 18psi is safe why do companies only offer 6-8psi as safe?

Because they are high. And because they want to have a reputation for being very safe, so they give very conservative numbers.

Boost is a byproduct -- just a number. It's a measurement of efficiency as much as anything else, which is why a stock 5.0L might make 280 rwhp on 6 psi of boost while an H/C/I 5.0L might make over 400 rwhp on 6 psi. So if you want to know how much a 5.0L engine can take, it's 450-500 rwhp with a safe tune. Whether it's 6 psi to get there, or 18 psi.

Dave

 

[Joe 5.0]

I understand the concept of boost. My concern was more geared towards the strength of the stock pistons. Is there anyone that you know of that has run 18 psi on bone stock internals for an extended amount of time? What kind of fuel mods would you need to run to support that amount of airflow?

 

[ProKiller]

that is alot of boost. and without an intercooler or any kind of intake air cooling device, i don't know how your going to avoid detonation. thats alot of compression for hypercrap pistons as well. i wouldn't that high at all. personally, i would leave the boost where you have it, get some heads at least. stock cam is good for superchargers, but you need heads to really let it breath. IMO, stick to the 13#s. and as HairyCanary said, if you put 500+FWhp on a block your on borrowed time.

 

[94GTLaserRC]

10-12 is the max "I" would go with if the bottom is stock, everything is "tight" and you dont want to be changing H-gaskets constantly.

RC

 

[go-stang5.0]

talk to 94sc5.0...i think I have the name right. he runs high 11's on stock long block (cobra intake) w/ the s-trim and boost cooler and PMS.

 

[TMC]

With a 7.25" crank pulley and a 3.33 blower pulley you should see 13+ psi with the S-trim. You shouldn't need a smaller pulley to see those boost levels.

 

[OinkAodeOink]

i ran 13lbs on the stock heads.. At that point i was right on the verge of detonation. I had the tweecer to control timing, but past 13psi, i had to cut back too much timing.
Invest in water injection, or a custom intercooler setup. Water injection would be much cheaper. This will allow you to run more bosot safetly. After all, its detonation that will kill the motor, as long as you have decent sized injectors, and fuel pump.

 

[94TURBO5 O]

I'm hitting 12#'s with the stock block internals, cam, and heads. I last dyno'd @ 392 in April before the PMS and Methanol kit. I'm hoping to be over @ least 450 now. Deteonation is the enemy like Mike said and the PMS and methanol totally makes it disappear.

 

[BlueOvalStangGT]

Ok well heres the deal. Im not running 13 like mentioned above, only about 10-11. This saturday it will finally get tuned since like spring(I got the blower belt off now to make sure I dont blow another gasket). I was thinking of going to steeda, finding the next pulley down from mine and then tuning with that. I dont have time to run a boost cooler right now. How much more boost will I make with the smaller pulley(wee lil bit smaller). Oh and when I get the boost cooler, I would need to go for a tune again right?

 

[94TURBO5 O]

If you have a 3.33 on it now just get a 3.15 or a 3.12 and you'll see 12 psi. You won't see it all until just about 5-6K and the key is not detonating. It's no fun to run such low timing either not being able to enjoy all the power just 10 psi can give you. You gotta be able to use what you got and run more timing to get your peak hp and a boost cooler will do that for you safely. If you don't have a WB then yes get a re-tune so you can get it set properly and know what's going on with your A/F. 94/95 just suck with detonation like a curse or something so be careful playing around with the boost until you can afford to change some more HG's.

 

[TMC]

Ok well heres the deal. Im not running 13 like mentioned above, only about 10-11. This saturday it will finally get tuned since like spring(I got the blower belt off now to make sure I dont blow another gasket). I was thinking of going to steeda, finding the next pulley down from mine and then tuning with that. I dont have time to run a boost cooler right now. How much more boost will I make with the smaller pulley(wee lil bit smaller). Oh and when I get the boost cooler, I would need to go for a tune again right?

Again,

You should not need a smaller pulley than the 3.33 with a 7.25" crank pulley to see 13psi. If you are not seeing 13# now than something is not right. The addition of a smaller pulley might actually create more problems either now or down the road.