87 oct equals considerable knock in the V6's

[bmwdon]

So, talking with Mike from Diablo on PM's yesterday, he let me know as other tuners have mentioned, there is not much room to gain on the 87 oct tune for the V6. He did mention there is a bit of gains moving to 93 oct simply by loosing a bit of knock. They could probably retune for the 87oct tune, but would have to retard some of the timing, so the knock would go away, but then the power curve would loose out. So basically tune it right, no knock, loose some hp and trq, but gain longevity in the engine would be my guess. So for those willing to go 93 on the regular, we're going to see gains. I wonder if the Dyno sheet circulating around showing HP#'s all over the place, if folks were using different grades or quality of gas (ethanol blends vs. straight gas). Was there a column for gas grade in that sheet? I can't recall.

I was curious why chevy engineered the engine with 6 bolt mains....not like that's a requirement for a engine that puts out 300hp. Is it to hold together longer on low grade gas causing knock?

I'll be telling the wife the camaro is now a premuim blend kinda car

[bmwdon]

this sheet is the one I'm talking about, besides the DA and actual dyno device used. http://www.camaro5.com/forums/showth...highlight=dyno

I wonder if gas grade would show some relation to HP#s more as well?

[ROD1]

Originally Posted by bmwdon

I was curious why chevy engineered the engine with 6 bolt mains.

Alum block with 300hp prollyz y.

[bmwdon]

I suppose, but even aluminum chevy V8 blocks come in 4 bolt mains http://www.summitracing.com/parts/WRL-084510/ , and then some run 6 bolt too. I don't know, seems like overkill for the output. But so did nissan with the skyline engine, and people got wicked hp #'s on just shoving air down it's throat to a fairly high number. Think they had to beef up the engine to go beyond 800hp or something nutty like that. Maybe in the end, we will have the american skyline engine? or am I thinking of the stock supra engine....crap, can't remember now

[hb35man]

Originally Posted by bmwdon

I suppose, but even aluminum chevy V8 blocks come in 4 bolt mains http://www.summitracing.com/parts/WRL-084510/ , and then some run 6 bolt too. I don't know, seems like overkill for the output. But so did nissan with the skyline engine, and people got wicked hp #'s on just shoving air down it's throat to a fairly high number. Think they had to beef up the engine to go beyond 800hp or something nutty like that. Maybe in the end, we will have the american skyline engine? or am I thinking of the stock supra engine....crap, can't remember now

The rotating assembly is fairly heavy on the V-6.T o safely spin the motor at 7000 rpm strength is needed in the main web area to prevent cap "walk".Tieing the main caps to the block skirt and then adding a rigid aluminum pan creates a lightweight and strong "box" for the for the rotating assembly to operate in. just my humble opinion

[bmwdon]

I can go with that. I was reading some of the alloytek or holden forums and companies that tune them, saw some mention of a rpm capable alloytek hitting 8725rpm....wonder how much bottom end work they did to do that

[bmwdon]

I wonder what is interchangeable from the aussies engine to ours..
http://www.performancemanifolds.com.au/

I sent these folks a email asking if their manifold would fit our V6's too, don't know if they would know or not, but I thought I'd ask and hopefully see what kind of price they are going for

[ROD1]

Originally Posted by bmwdon

I suppose, but even aluminum chevy V8 blocks come in 4 bolt mains

But a 6 has 1 less main. Coincidentally the L99 puts out the same power per cylinder as the LLT.

[MontyCarlo]

Unfortunately the gas stations around here don't offer 93. Just 91, 89 and 87.

[brandotron]

As far as I know, all Gen 3 and Gen 4 engines have six bolt mains, starting with the LS1. That may have been a jumping off point in te development of the v6.

[rays]

Read up on how DI works.

[bmwdon]

so knock is inherent to the DI design, especially in a "ultra lean burn mode"...interesting, learn something new all the time but it still seems running 93 octane produces more power and reduces that inherent characterisitc right?

[mrray13]

Originally Posted by bmwdon

I wonder what is interchangeable from the aussies engine to ours..
http://www.performancemanifolds.com.au/

I sent these folks a email asking if their manifold would fit our V6's too, don't know if they would know or not, but I thought I'd ask and hopefully see what kind of price they are going for

That's an alien looking thing, lol. But if it works, great! Wonder what it would set a person back?

Originally Posted by MontyCarlo

Unfortunately the gas stations around here don't offer 93. Just 91, 89 and 87.

Same here. 91 is the best available.

[bmwdon]

they haven't returned email yet on the intake manifold, my guess is they are sleeping or something

We get 93 oct around here, but w/ 10% blend. So whenever whoever comes to the table with a tuner or if not, I go to a company to remote tune the car, I'll have it done to 91 oct fuel and run 93 locally and consider myself safe when traveling across state lines