I had a freind dyno his 2000 5.3 with those mods through the stock y-pipe and cats and got 241hp 263 tq. He was very disapointed but I thought that would be about right. The dyno shop showed him in a book they had where the 2000s only had 220 hp I told him that must be rwhp he said not. He is thinking that since his truck did not make 285 hp like its rated it is a lemon. Since TAs and Camaros dyno 300+ and are rated at 305 his should also. I tried to explane the parasitic losses are much greater on a truck than a 6 speed car. Someone with experience on this please chime in.

 

Oh and with his HPP3 programed in he lost a solid 10 rwhp. He gained some tq down low but more than lost it + 10 up high.

 

The HPPIII, advances timing. It is possible that with the advanced timing, he got major knock retard which would make his numbers go down. Now, with the JBAs, catback and cold air, he should be looking at 250+. 241 with those mods are low IMO. I dynoed with my 4.8 in the beginning with a catback, Airraid, pulley, and HPPII and I came out with 247rw. Now if that shop has stock 5.3's on the book at 220rwhp, I would find a different shop. Are they taking the dyno up to 128? are they dynoing in 2nd gear only? How many miles on this motor? What gear? Sorry, but 220 for 5.3 is still low IMO. Sounds like he has some tunning issues.

 

ASM headers, !cat stock y-pipe, Gibson super truck
exhaust, hpp3 93 tuning on my 2000 5.3 2wd made 260/315 at the wheels.

Jay Johnson

<small>[ November 24, 2002, 02:33 PM: Message edited by: Jay Johnson ]</small>

 

dont the diferent types of dynos vary alot too, i have alway heard the mustangs will read alot lower than the dynojets.

edit... just did some research on the diference between dynos and it seems that most people go with 5% or more higher for the dynojet unless you have a turbo then things may change to where the mustang reads higher than the dynojet. if he was on a mustang than he would be 250+ on a dynojet.

<small>[ November 24, 2002, 10:19 PM: Message edited by: parish8 ]</small>

 

What Parish said is true, but if your loosing power with a HPPIII, you got other problems.

Greg

 

It was a dynojet. He did 3 pulls and the one with the Hyppertech lost him 10 rwhp.

 

Yes, it's possible to lose power with the HPP3. As Fast4.8 mentioned, you can get some bad KR with the added timing to the point that you're making less power with the power tuning. It happened to me on my '98 T/A. I'd redyno with a few gallons of unleaded race gas and see what it does. If it still shows a HP loss, then there's something else wrong. Is there anyway you can AutoTap the dyno runs? That will show you where the HP is going.

Trevor