I was just wondering what type of gains were seen from people who went from a mail order to a dyno tune. And any other observations such as better throttle response, smoother idle or whatever. I hear rumors of 75-90 rwhp from getting a custom dyno tune. Is this true?

 

75-90 on a heavily modified setup. a truck with boltons like mine will see about 25-30. in person tunes are better because the tuner can see exactly what the truck is doing. for example, my truck was having problems with the descreened MAF. i never woulda known it if i got a mail order.

 

All I have done is 4.10's/Eaton and Radix with a 3.2 pulley, seeing 6 pounds right away and about 9 pounds on top. It is real slugish with my newest mail order tune and even stumbles sometimes in the low rpm range. Fuel pressure stays at 58-65 at WOT. Seems as if the air/fuel tables are off. My plan is for next Friday to get the dyno tune. I'm hoping I'm over 300 rwhp, I was 230 before the radix and gears.

 

Another option would be if you have any way to do some logging, then send the results to the tuner. That way, he should be able to get it pretty close. I agree with everyone about the mail order tune being a "shot in the dark, sometimes", but not everyone lives within a reasonable distance to the better tuners, so that's the only option. If you already have a mail order tune, and can get some logging info doing a street log, get that info to the tuner, and use your update option, whatever that may be. Could be a lot cheaper than getting another whole new tune. Just my $.02

 

I don't know anybody in my area who has any logging software. I don't even know another chevy truck guy who likes to go fast. I will be getting a Predator hand scanner with my dyno tune. He gives it to you with your tune in it just in case....plus I can scan codes and it does monitor some things like TPS and fuel trims etc. The tune, dyno time, and the predator are gonna run me $600. Worth it to me to get the most power I can and not worry about blowing things up. Hell, a predator with a crap off the shelf tune is $400 most places. Plus he will do free updates with future mods. E-mail him the new info he adjusts the tune file, e-mails it back, I download to the predator, and put it in my truck. Is ANYBODY dissapointed with thier dyo/street tune?

 

The stumbling could be tq management.

 

I would highly suggest the Dyno tune. I have not had good luck with mail order.

 

Never did it with the 3.4 pulley. Only started with the new tune for the 3.2. I never thought about tq mng. I don't know what it really does other than pull timing to decrease power/tq. It doesn't bog down up top only at partial throttle. Say I'm going 45mph and give at 1/4 more pedal to change lanes and slowly pass someone...it bogs down right as I press the pedal. I press a little more and it doesn't get better, then, BANG it comes back alive and jumps forward like I nailed it. It's like the computer can't compensate for the air fast enough or something. I'm no tuner but, I have a checkbook, and I plan to get it fixed!

 

Scheduled for Friday 0930

 

I gained 20hp/30tq from dyno tuning over the mail order tune for the radix. Mainly because the mail order was 'safe' and we were able to add some timing and lean it up a hair on the dyno.