Last Call

iTrader: (4)

I bought a 3.0 inch pulley from Nelson. I installed it on the truck and took it to have it tuned. There is a lot of knock preventing the truck from going past 5000 rpms. Im seeing close to 10-11 pounds of boost.

I will be going to a 3.25 pulley and tuning for that. I was just wondering how those people with 3.0's are tuning there trucks. Could it be the California 91 octane? Are you guys running race gas? Did you gut your cats and run true duals?

Just kind of frustrated right now. But after talking to a reputable source, it does seem than a 3.25 is the smallest to go without causing engine damage over the long run. I don't want to blow my motor trying to run too much boost.

CHarris

iTrader: (5)

Did your kit come with a 3.4 pulley? If so, that was big jump to go to a 3.0.

My kit came with a 3.1, but it is a 6 liter set up. I expect a 3.0 pulley to give me about 8-8.5 psi when I finally go there.

Mr. Sandog

Hard to decipher exactly what is happening with your situation. Did you go to Allen to get tuned, or somewhere else? If somewhere else, where?

Did you just put on the 3.0 pulley and try driving around? Bolting on a 3.0 pulley and trying to run your truck with a 3.4 pulley tune, well, I would think your results (knock and KR) are to be expected. You really need to tune for the pulley you'll be running.

I don't know that I would worry about the motor with a 3.0 pulley (unless you don't get it tuned, of course). I would be much more worried about the drivetrain.

lm7

iTrader: (8)

im no radix expert but i dont see why with the proper injectors and pump (which radix suposbly comes with) and a good tune 10-11 psi wouldnt be possible. i think either your having some kind of a fuel issue or a bad tune. 91 does suck tho try mixing in some 100 if theres a pump near by to see if i rids it of the KR then it will be genuine KR.

Last Call

iTrader: (4)

I installed the 3.0 pulley and then drove it to the tuner right away. He is the one that seen the 10-11 pounds. He was montoring the truck and adjusting the tune with HPTuners. He couldnt bring it over 300rwhp. I dynoed 370rwhp with a 3.6 pulley.

IAT's were like 120 on the street and 140-150 on the dyno. I know that doesnt help the situation. I guess it just sucks that my hopes for 10 pounds of boost went down the drain.

As far as my drivetrain, that should hold up okay. I wont be running slicks and have a built transmission (4L65) and an Eaton Posi.

The_Mexican

I had the 2.90 pulley with nelson in my last truck (5.3L) and it ran a lot better, you need to check the tunning. It shouldn't be like that.

Give Allen a call, I'm sure he'll help you with that problem.

Flyer

iTrader: (1)

Those IAT"s are high, but well within reason considering 10psi. I agree ... it's got to be in the tune.

Mexican, did you put the blower on your new truck?

O3GMC

Get a tune from Allen. He knows how to tune for boost. Another option would be some alky or meth/h2o injection to prevent detonation and bring the IAT's down. Any amount of boost will be fine if its tuned right (within reason of course)

The_Mexican

what he said.

I still haven't, but, I hope that I can go to San Antonio this weekend or the next for sure to have the cam, charger and gears in the truck.

F8L Z71

Those IATs are very high IMO....

I doub't it's a lack of tuning knowledge as Rick has tuned my truck with zero problems and making a tons more power and numerous other FI cars that are hitting close to 700rwhp.

There is another issue here I think. I was rackin my brain trying to figure out what it could be when Rick called me yesterday to verify that the old dyno was 370rwhp.