GEP 6.5 NA - Max Boost & HP/TQ

[jrtoffroad]

Some of you guys might have seen a thread of mine a while back discussing swapping to an LS engine in my HMMWV. Well, after enjoying it for a while now I've developed a bit of a soft spot for the 6.5 and am wondering what reasonable HP numbers can be achieved.

I have a D1SC Prochager I'm planning to install with a good size A2A intercooler and am wondering if anyone has pushed one of these hard enough to do damage or lift a head? What is the max boost anyone has safely (or not safely) run? Any dyno numbers or performance numbers (0-60 1/4mi)?

What has everyone found the limit of the stock fuel system to be? How far can you go before injector & fuel pump changes need to be made?

I happen to have my own chassis dyno, so will do some before and after testing and post results.

 

[rcamacho]

Sent from my iPhone using Tapatalk

 

[Mogman]

I really have no answers, but I am curious as what engine you are starting with (GEP?) and why a mechanical driven compressor is preferable in this case over a wasted exhaust energy recovering turbocharger? Certainly EGTs will be your limiting factor not raw HP

 

[jrtoffroad]

I really have no answers, but I am curious as what engine you are starting with (GEP?) and why a mechanical driven compressor is preferable in this case over a wasted exhaust energy recovering turbocharger? Certainly EGTs will be your limiting factor not raw HP

I have a GEP engine.

The primary advantage of a procharger is that I happen to already own one.

It will not compete with a turbocharger for efficiency, but I do love the instant boost and standalone oiling system. The rising boost curve is typically very easy on an engine and its capable of big power (if the engine will take it). I haven't done any mockup, but I'm hoping I can use the empty AC compressor mount for an easy install.

I dont think EGT's will be a big issue if I keep my hp goals reasonable. I should be able to keep them in check by maintaining low iat's and high airflow/boost for a given fuel setting. I'm more worried about potential modifications to manage coolant temps.

 

[Mogman]

I have a GEP engine.

The primary advantage of a procharger is that I happen to already own one.

It will not compete with a turbocharger for efficiency, but I do love the instant boost and standalone oiling system. The rising boost curve is typically very easy on an engine and its capable of big power (if the engine will take it). I haven't done any mockup, but I'm hoping I can use the empty AC compressor mount for an easy install.

I dont think EGT's will be a big issue if I keep my hp goals reasonable. I should be able to keep them in check by maintaining low iat's and high airflow/boost for a given fuel setting. I'm more worried about potential modifications to manage coolant temps.

You would probably need to replace the radiator with an aluminum one, that is what I used on the DuraVee and the temps are completely under control even with the 435HP tune, but the Duramax is a much more efficient engine than the Detroit.

 

[jrtoffroad]

You would probably need to replace the radiator with an aluminum one, that is what I used on the DuraVee and the temps are completely under control even with the 435HP tune, but the Duramax is a much more efficient engine than the Detroit.

Which radiator did you go with? Are you running the stock HMMWV fan, or the duramax fan (or something else)?

BTW, you ever done a 0 to 60 run on the duravee? Curious how fast it is. Bet it's pretty fun.

 

[Mogman]

Which radiator did you go with? Are you running the stock HMMWV fan, or the Duramax fan (or something else)?

BTW, you ever done a 0 to 60 run on the duravee? Curious how fast it is. Bet it's pretty fun.

I am running a modified Dmax fan and clutch, 0-60 about 6 seconds (would be less but I keep forgetting to put it in 4WD and allot of time goes up in smoke) vs 27 in my 6.2L helmet top
I went with the cheap Champion radiator seems to have decent build quality

 

[Mogman]

The 6.5L Detroit suffers from some of the the same problems that plagued the 7.3L ford, one is they did not do enough to keep the heads on, you can quickly get to the point that you start to "lift" the heads and blow a head gasket, fixing that short coming can be rather expensive, this is why even the turbo GEP should be kept under 250HP

 

[Barrman]

Bill Heath at Heath Diesel took a 6.5 truck to the Salt Flats a while ago and ran over 150. Twin turbo and all kinds of modifications. Many articles on the internet about his engine and truck build for that run. If you call the business during lunch time you will often get him answering the phone. Nice guy to visit with.

 

[jrtoffroad]

The 6.5L Detroit suffers from some of the the same problems that plagued the 7.3L ford, one is they did not do enough to keep the heads on, you can quickly get to the point that you start to "lift" the heads and blow a head gasket, fixing that short coming can be rather expensive, this is why even the turbo GEP should be kept under 250HP

I haven't had much time to start mocking up the procharger yet, but I do plan to at least do a fresh set of head gaskets and ARP studs. I won't be too upset if I catastrophically find the boost limit, as long as I find it relatively close to home.

 

[Mogman]

Bill Heath at Heath Diesel took a 6.5 truck to the Salt Flats a while ago and ran over 150. Twin turbo and all kinds of modifications. Many articles on the internet about his engine and truck build for that run. If you call the business during lunch time you will often get him answering the phone. Nice guy to visit with.

As I said expensive.
Put that kind of money into a Duramax or a Cummins and you are way north of a thousand HP, just saying.