the cool thing is this actually an ls6 short block. I also have low use lifters for it.

 

ehhh. I already have an aluminum 5.3 in the car. I wasn’t adding that weight no matter what.

 

Why goes going from a 5.7 to a 6.0 or 6.2 require upgrading the trans/DS/CV/rear? Like the extra half liter requires a whole drivetrain reconfiguration? Even the turbo isn't a big deal now with all of the cheaper options out there. More cubes will drive better with the same sized cam as well.

 

Sorry I thought it was iron. If it's aluminum definitely just do the cam then

 

every step up I’d take will make more and more tq. And even more tq is going to shred the parts I have now. Plus it doesn’t make sense to go buy more parts instead of use what I have. And that’s one of the main reasons for doing it….I got the forged pistons and rods for no money. So getting a 6.0 or 6.2 would totally defeat the purpose.

So you think a 7875 won’t be a problem with back pressure on a heads/cam 6.0/6.2? on ALL the boost?


lets just say that a 7875 on a 383 or 6.2 isnt quiet ideal at higher boost levels. Yea, it'll work on a 6 liter up to a point, but it'll be a restriction at the levels i'll be taking it. Like I built a turbo kit for a guy with a 6.0, 7875, on 10psi its fine. if he decides to push it, we gonna have to rethink the turbo choice....

 

Youve said in the past that you dont necessarily want more power, but felt like the 5.3 was soggy or didnt have as much low end grunt. A 7875 is perfectly fine if you keep boost to around 1 bar and have adequate exhaust. It'll give you all the part throttle you want and drivability....BUT you can control torque with your fancy boost controller as well as timing. You may even be money ahead if you sold your 5.7 stuff already assembled and built a new 6.0 setup for instance.

 

If you sell free parts you have profit to buy other parts! Tq can be controlled many ways, it doesn't have to be a drivetrain evicting hammer. It's not an optimal turbo for that engine but it works just fine, guys run 9's all the time with 7875's on 6.0's. Years ago my 6.0 saw over 30lbs from my 7675.

 

Damn Tree'd by 3 min!

 

Well see, thats the thing. I won't want to limit myself to boost lol. Do we ever? My buddy went 9.70's with the 5.7 these pistons and rods came out of. Full weight transam, stock unported heads and stock ls1, not ls6 intake. I think this setup with better heads and intake than he had, should make just as much power or more than he did. likely more. I really dont need/want anymore than that. If I have the potential...i'll turn it up....

 

The end.

 

so that doesnt tell the whole story.....so its not quite the end..lol

what exhaust housing did it have? What was the back pressure like? I'm no professional, but 30lbs on a 7675 on a 6 liter doesnt sound very optimal. was this a precision turbo? Turbonetics? Or china boi?

 

honestly i've tweaked the tune good enough to where its much better than it ever has and boost does come in very quickly. its not quite NA responsive, but its responsive enough that most people that I take for a ride notice the lack of lag and the good response it has. I just find as time goes on and gas prices get higher, I find myself wanting it to be more efficient and quieter . guess I'm getting old?

 

You're looking for excuses to justify your plan which will give suboptimal results compared to what it could do for the effort spent. You asked for thoughts, and now have some. GL with the build

 

Is the 5.7 engine you have the original factory engine for your GTO? If it is, I would run that. Assuming you don't kill it You have the bits already and are looking for a change, I can't see why you wouldn't do it. Sounds like anything else is chasing very small differences which may not be worth it. Even if you're not happy, sounds like you wouldn't have much in it.

That 204/222 cam is Interesting, very low IVC if I'm not mistaken, 32? 45 on the exhaust? My previous 214/217 baby cam was 35 IVC and it was very punchy down low. Great for moving my heavy car (5.7 04 GTO equivalent). My TSP 216/220 .600/.600 112 is great but has a touch less down low. I may have run it +4 instead of the standard +2. Brings the centreline from 110 to 108, IVC from 38 to 36. Although, it may have an affect on top end, I like the 7000rpm top end of this 216/220 and it revs harder than the 214/217. I will be interested in your results.

 

Hey man, thanks. I'm not looking for excuses tbh. The point I was asking is, would it be likely that a little bigger engine with about half a point more compression....would it make about the same power as I have now? I'm not really looking for more power, it has plenty..i just dont want to lose any. I would like a smoother, quieter idle, better fuel mileage, maybe a lower rpm idle for less fuel consumption. Basically i'd like about stock fuel consumption and exhaust volume (noise) but then the turbo will make the power. I feel like If I swap motors i can kill more than one bird with one stone....The motor mounts....I put the revshift Green ones. They suck! I hate them, so I'm going to put softer mounts in. Also, seems like i've got maybe more blow by on the rings....it started popping the dipstick up a couple months ago. I had to put a vent filter on the valve cover for now to stop it. Excuses....I guess...more or less excuses to pull the motor out and change some things up, hopefully for the better. I was just on the fence about using a smaller camshaft.

 

What are your HP goals? I assume not very high if you are worried about breaking OEM GTO drivetrain components.

I've run the Precision CEA 7675 with .96 AR over priced wonderboi, as well as the VSR 7875 with 1.25 AR. Are they optimal on a 6.0, nope! But can they still make 800WHP, spool fast AF, and get a 4000lb car in the 9's, yup!

 

I've got a 227/234 in a 5.7 and it isn't too big. A 222/233 cam in a 5.7 will provide plenty of low end torque. The LS6 cam is weak.

 

​​​​ The "ls6" cam we are talking about is cut on a 112 LSA closes the intake valve 10° earlier and it has more exhaust duration and lift It's not anything like a regular LS6 cam It's completely different.

 

it’s not too big as in what? I mean the cam I have now is not to big in general, but what I’m looking for in my setup, and with my car…it is. I want a better, lower rpm idle. I want more cruising torque. I want better fuel mileage. I want a lower volume of noise emitting from the exhaust. Is there some sort of switch I can flick on this cam to magically change it into what I want? No. Lol.(I meant that as a joke btw) Don’t get me wrong, this cam I have is great, one of my favorites so far. I just want to try something a little less aggressive.


i gather that he just scanned through the thread and didn’t catch everything I wrote. It’s ok, it’s to be expected. Everyone like to give their input.

 

I jumped on this thread because I have a higher than stock compression N/A 6.2 that I run in front of 2.73 gears daily. I was running a summit 8714 (226/230-112+4) and I love it I was just tired of the gas mileage with the fuel prices the way they are it's insane and it's easy for me to change cams and so I swapped the summit 8714 for that SDPC power max and kablamo the car picked up power everywhere got better mileage and got quieter and my neighbors started talking to me again at least with my gearing it feels like that way to me lol so I feel like the OP would really love this cam change for his setup am I wrong? I put together a half dozen engines and changed dozens of cams I don't know everything but I learned something when I changed this cam about the IVC and compression and I'm glad I did So maybe that is the same thing with boost That's why I really want the OP to just try the little 204-222-112 + 1 or something buy it and check the cam card lol remember everybody was freaking out about the isky triple 12 This is like that but optimized