I have a 99 Ex Cab Short box with
5.3,4L60, 3.42's, 27.7" tires on 20's, Westers 89 tune, Doug Thorley Tri-Y's, True Dual w/ Flowmasters, LT-1 Electric fans, K&N Cold air intake and a vette servo. I ran it on a G-Tech on a 90 degree day and I ran a 16.2 for my best time. That is horrible, I thought it would be better than that. I just bought a Whipple that is going on in 2 weeks. I got the complete Westers Whipple tune (eliminates the Whipple harness) 42lb injectors and I will be bumping it up to 8lbs of boost. What kind of power should I be putting out then? And could I hit 13's in the 1/4? I was thinking with the mods I have I should be in the 15's but obviously not. What does my truck run stock in the 1/4?? Also he ran a Z28 Camaro on the G-tech right after me and it ran a 14.6, so I don't think thats screwed up.

 

ummm...yea....you would hit 15's..but..lol....20s are just kinda heavy lol.

 

Heat kills performance. Besides, if the Z28 you mentioned was an LS1 and ran a 14.6 than those measurements are worthless. Bone stock LS1 camaro's run low 13's all day.
To run 8lbs you may need some alky. Good luck with the Wester's tune. His crap was the biggest waste of money ever. I had him send me an update when I put my Vortech on and it took him 6 weeks to send it. It then detontated so badly that the truck was not drivable. He then wouldnt send me an update until I proved to him that I really had 43lb injectors (wanted part numbers from a rep at ASM). I ended up eating the $500 from his **** poor shop and spending another $400 or so for a real dyno tune. If you can get a refund DO IT. I would get Nelson to do your tune. Lyndon's service sucks and from my experience so does his tuning.

 

The camaro was a 97 LT-1 which I believe are supposed to run around 15 stock. Everybody else I talked to said I could run 8lbs without detonation, but 10lbs I would need alky. My Westers tune helped my truck right when I put it on, and I talked to them Friday and the new computer will be sent out before the end of this next week. Lots of people love the Westers on Fullsizechevy.com . I don't want to start a pissin match though

 

Do a search for Ranwalk. I believe he had knock at 8#. Im sure it depends on how hot it is, but I would definately have some sort of logging software to check for knock unless you are looking for an excuse to throw a new 6.0 in there.
Good luck with the tune. Just sharing my experience with you, that wasnt an opinion, it was a 100% truthfull account of my experience with them. I went with Wester's before I came over here b/c of people at FSC too. You may want to look into HPtuners. They include a logging feature with the ability to tune.

 

Greentahoe is on the right track,

IMO I would either fab up an intercooler or run Alky even if you only planned on 8psi. You will see much better HP with it. Even if you don't detonate at a particular psi you can still benifit form the cooler intake charge because #1 the air is denser and #2 the PCM wont be pulling back timing like so commonly happens with FI trucks.

One thing you didn't mention is if it was an old or new style G-Tech and the 60'. The LT1 autos generally do run 14.2-14.7 and the sticks anywhere from 13.7-14.2 stock but the 60' will make or break a 1/4mile run and those torqy LT1s sometimes have trouble. You on the otherhand probably had plenty of traction I assume?

With your mods I would have guessed 15.8 or so but since it's a 99' it's tough to say with your PCM problems. if you can get everything rigth with the Whipple 13s is a go but I wouldn't expect anthing better than mid 14s right off the bat unless you are one of the lucky ones.

The Silverado SS in my area only ran 13.8 with a Radix. Then added a 75shot and went 12.5. Amzing what cool air can do

 

Has anybody here fabbed an intercooler for a whipple? And would an import one work or do I need one from another charger for one of these trucks? When I ran 16.2 I spun for about 10', but when I hooked up I ran 16.7. Weird. It was the older style G-Tech and I don't know what the 60' time was. The Camaro was a stick and he launched at 3,000.

 

Ryan23 has an awesome intercooled whipple setup. He is a mod here. There are pics in his sig.