Max boost and EGT's on a 6.2? Maybe an FAQ is needed?

[turbovanman]

Ok, maybe its mentioned but I can't find it, maybe put this as an FAQ as I am sure others also want to know.

What is the max boost allowed, GM X turbo, on a stock 6.2 and max EGT's? If using a different turbo, how do I know what boost to run without it going boom?

To throw another wrench in it, I'll be doing a remove mount turbo so that will lower my EGT's being read if I use the turbo or should I put the probe up at the headers or collector?

 

[Missy Good Wench]

To really know whats happening with the EGT the best spot for the probe is in the LH exhaust manifold right as it drops out to the Xover pipe.

Max boost is about 10 PSI maybe a tad more. Max EGT is 1000F

Banks speced this stuff out years ago and they saw very good dependability with these numbers.

Remember, the 6.2 does not have coated piston crowns. This is not an absolute neccesity but it does protect the psitons some.

Keep within those #####'s and you will be fine.

Too much boodt just heats the intake air up way too much and drives the EGT up too.

I have run the 6.5's at 12 PSI and they will do fine but much more and it starts to cause issue.

Running the EGT over 1000F is just looking to melt the little creature.

I have seen guys run them at 1200F but thats getting out on the edge of the envelope beyond my comfort zone.

Missy

 

[turbovanman]

Ok, max is 1000 deg's, got it.

Now if I use a different turbo, does the boost still matter if the EGT's are low?

Won't a remote mount turbo change the EGT's? If I put it up at the header, is that still an accurate way to measure?

 

[chevyCowboy]

if a guy was to use a 6.2 block and drop the compresson to say 18:1 and run 6.5 heads and turbo these max #'s for boost and egt whould change correct

 

[randomid25]

boost numbers would change. EGT would change as well if the pistons are coated.

 

[turbovanman]

if a guy was to use a 6.2 block and drop the compresson to say 18:1 and run 6.5 heads and turbo these max #'s for boost and egt whould change correct

Yes, but more than a head change is needed, the pistons have to be swapped out.

 

[chevyCowboy]

who makes lower compression pistons for these motors is the crank any stronger in the 6.2 than in the6.5 where can one get thicker head gaskets???

 

[turbovanman]

who makes lower compression pistons for these motors is the crank any stronger in the 6.2 than in the6.5 where can one get thicker head gaskets???

I don't think they make lower compression 6.2 pistons anymore from what I've read. On another 6.2 build up, the 63 1/2, they took .010" off some stockers and it lowered it to 20:1. Thicker head gaskets are used when you deck the block. I guess you could use those if you wanted, the gaskets are an extra .010" thick so that would be .020", probably another 1/2 a point at least.

Crank is just fine, I think the crank goes due to the block cracking and flexing so much. A good damper will help, fluid damper is worth every penny.

 

[chevyCowboy]

so is it posible to get 18:1 out of a 6.2 with 6.5 heads i would relly like to get that low. i want to try and get the most power out of one of these motors that i can.

 

[turbovanman]

so is it posible to get 18:1 out of a 6.2 with 6.5 heads i would relly like to get that low. i want to try and get the most power out of one of these motors that i can.

Different heads won't lower the compression.

 

[Ratman]

SNIP.... the gaskets are an extra .010" thick so that would be .020", probably another 1/2 a point at least.

.020" reduced compression height will drop it from 21:1 down to 19:1 (to be fair, I will say approximately).

FACT: -to go from 21:1 to 18:1 only requires .032" reduced compression height.

 

[chevyCowboy]

so what about with different pistons is it easier to reach 18:1 with them

im still new at this and tryin to figure out what im ganna do when i rebuild

 

[turbovanman]

.020" reduced compression height will drop it from 21:1 down to 19:1 (to be fair, I will say approximately).

FACT: -to go from 21:1 to 18:1 only requires .032" reduced compression height.

Interesting, ):h