PRC 250CC Castings/G6X3 Cam results

[ULTRAZLS1]

Coming this week

Dropping the car off tomorrow morning for the install.

I know a few different people are wanting to see some more numbers with these heads. Figured I would post up...

Set up is as follows
-Stock bottom end LS3
-PRC 250CC aftermarket casting cylinder heads with 67cc combustion chambers
-.040 cometic head gaskets. (yields around 11.4.1 scr with 67cc chambers)
-G6X3 camshaft
-Fast 102 intake manifold
-Nick Williams 102 throttle body
-93 octane dyno tune
-stock gears and clutch
-Other mods etc are in the sig.

Hoping for in the neighborhood of ~520rwhp. I'll have the results up some time this week.

-Troy

[thesnoopster]

Nice build sheet....hope you get some awesome results!!

[Zyklon-SS]

[Busy_Boi]

[Sebastian]

post ur results if you got it on a dyno. sounds like a good build up so far.

[Dznts]

[ULTRAZLS1]

I'll have a dyno print out I am sure. Most all shops give them I would think.

Really hoping these heads work well with the G6X3. Went out on a limb here thinking that they would. I know the cam works well with ported stock castings in the same compression range.

Only thing I wont have is a before and after on the same dyno. The car has 6 month old oil in it from sitting for the winter. I opted out of the baseline pull because they are going to change oil after the install anyway...and didnt want to run it to redline with used up oil for the baseline.

I know some have set limiters to over 7k with the G6X3 but opinions vary.

I told them to set it at 7k unless it was falling off way early for some reason or if still pulling they could go to maybe 7200.

Where is everyone else at with the rev limiter on a G6X3?

I have seen some keep it at stock 6600 and others up to 7500. Figured 7k would be a good happy medium. Its no track car but I want to get the most out of it.

[MikeOD]

I'm looking forward to your results...I need to get my car on the dyno too!!!

The last G6X3 car I tuned, has the rev limiter set right at 7000 RPM. G6X3, ported LS3 heads and stock displacement but with forged pistons. Not my car, a friends car.

[ULTRAZLS1]

Originally Posted by MikeOD

I'm looking forward to your results...I need to get my car on the dyno too!!!

The last G6X3 car I tuned, has the rev limiter set right at 7000 RPM. G6X3, ported LS3 heads and stock displacement but with forged pistons. Not my car, a friends car.

Thanks for the input.

I told him 7k and he kind of paused for a second...I am not sure if they will be taking it that high or not. We will see.

From what I have gathered the G6X3 doesnt hit peak hp until about 6400-6500 rpm...and I would like to be shifting a few 100 rpm past peak. Figure if I get a shift light 6700 would work well with a 7k limit.

Glad to know you didnt blow your motor...just a ground right? LOL...that would have scared the hell out of me.

[MikeOD]

Yeah, I felt like an idiot when I remembered finger tightening the drives side coil ground, turning to grab a wrench, and forgetting what I was doing.

Needless to say I went through every single fastener under the hood again after that...the car is ok now lol. Soon as I get the 102mm TB and take care of some minor exhaust work, I'll hit the rollers.

For what it's worth, I would see where it makes power, and set your rev limiter accordingly. Your valvetrain should be up to the task, so the only real risk would be rod bolts, which seem to be better on these newer engines. Plus drag racing and occasionally spinning it up high on the street isn't nearly as bad as the sustained high RPM abuse it'd see road racing or something.

[Kyle2k]

Originally Posted by ULTRAZLS1

Really hoping these heads work well with the G6X3. Went out on a limb here thinking that they would. I know the cam works well with ported stock castings in the same compression range.

Lol, why wouldn't it? It has better flow, a different valve angle and smaller combustion chambers to increase compression.

[AG454]

Good luck Troy, I think 530 rwhp.

[ULTRAZLS1]

Originally Posted by MikeOD

Yeah, I felt like an idiot when I remembered finger tightening the drives side coil ground, turning to grab a wrench, and forgetting what I was doing.

Needless to say I went through every single fastener under the hood again after that...the car is ok now lol. Soon as I get the 102mm TB and take care of some minor exhaust work, I'll hit the rollers.

For what it's worth, I would see where it makes power, and set your rev limiter accordingly. Your valvetrain should be up to the task, so the only real risk would be rod bolts, which seem to be better on these newer engines. Plus drag racing and occasionally spinning it up high on the street isn't nearly as bad as the sustained high RPM abuse it'd see road racing or something.

That is basically how I left it with them...hopefully they do it right.

[ULTRAZLS1]

Originally Posted by Kyle2k

Lol, why wouldn't it? It has better flow, a different valve angle and smaller combustion chambers to increase compression.

Well the G6X3 was originally designed for the stock LS3 heads which have a larger runner. For this reason many of the cams use a wide split between the intake and exhaust valves for best performance on low velocity runners. The specs on the G6X3 have never been released but I think it is in the neighborhood of 235-242 from the research I have done. Whether or not the increased velocity of these heads will help or hinder the G6X3 has yet to be seen.

It should work just fine but I guess you never know...it would be just my luck if it runs like crap :(