i got my 100hp ddp sticks in yesterday and i love em. they make great power. i was wondering though, how much boos is too much on a stock turbo? i can hit 38-39 pretty easy and have seen as high as 40. thats with a boost fooler. also wanna know how high i can let the egt's go? i can push them well into the 1500 range with no load.


thanks

 

35psi is usually tops for a HX35. You can go past that, but you're out of the efficient range of that turbo and it ends up doing more harm than good. If you have an adjustable boost elbow, you can dial it down some to allow the wastegate to open around 35.

As for EGTs, it all depends on how long you stay there. Competition guys spike higher than that, but it's only for a few seconds. Once I get around 1350-1400, I'm either backing out or shifting if I know the load is going to be sustained.

 

I ran 43 psi on my HX before I swapped my 62 on. As for EGT's, my 24v has seen temps of around 2400 degrees (estimated, took about 5-6 seconds for the needle to come off 1600 after letting out of the throttle), and it runs just fine.

 

so as far as egt's, as long as im not holding it at a really high temp for a extended period of time, i should be fine?

 

Its that theory that I am relying on.

 

Me too. I only got a 3 second delay on mine, but I have less fuel.

The problem too with stock turbo and high boost levels is the head gasket. The drive pressure is much higher at 40psi on the HX than a similar aftermarket upgrade. This causes higher firing pressures and possible head gasket problems.

 

just make sure your pyro is good to go, I had to do a rebuild i believe because my pyro was about 3 years old and i was hitting 1400 a few to many times and with the pyro bad I may have seen higher. what is good on one truck may not alway fly on another. studs would be good for a investment too. but the rebuild gave me a chance to put in the cam also. $$$$ learn from the ones that break things.

 

Mr Aggie, how is your SO pump? how long ago did you switch? are you happy with it.

 

I would put on a bigger turbo and run water/methanol spray. It helps to keep the valve seats from cracking and/or burning out.

 

I switched over in March '08 when my original HO pump failed. I've been very happy with it so far. Without the Smarty or any extra fueling, you can feel a little less bottom-end responsiveness, but once the Smarty is installed you don't notice it. The top-end is completely different. When I was running a TST, there was no difference between the highest levels and the middle levels. Once the SO pump went on, level 9 on the TST was a crazy ride compared to level 5 or 6.

It was a straight forward swap with no issues.

 

Thank you, I will be looking that direction when the HO gets more miles on it. yes I understand the higher levels do not seem to produce.

 

HO fired VP truck seem to max power out around 475-500rwhp. SO's seem to have fuel for 650-700rwhp.

 

40-45 pounds of boost is enough to blow a stock hx35.