Thrasher on '84

[6SENSE]

Got a Thrasher92 chip this past weekend. First thing I noticed (and wasnt surprised, knowing how our hotair cars are) was that there was no way I was going to run 45psi FP like they say it is IMPERATIVE that you do.
I have been playing around with the FP and now have it down to 34psi static. Still no knock with about 24psi boost, O2s are still around 800 or more! At idle I havent been able to get the O2s down, they are around 700-750!
I like the smoother idle and driveability, but performance has really sucked so far with this chip .

How low have you guys had to set your FP at to use this chip? Anyone with similar mods to mine?

P.S. Im interested in what aftermarket chips have worked for you guys, I will start an new thread for this.

 

[GNeric]

I have to have my fuel pressure at 40psi with my Thrasher 92. I am at 4000ft altitude and if I try to run the 45 it calls for, it belches black smoke. I even run 21psi on the street and 25psi at the track. But I also have Blue Tops, TA-33, ported heads, bigger cam than stock.

 

[6SENSE]

Sounds like you have a similar buildup to mine GNeric (see sig below), I guess the altitude makes a difference, huh?

 

[FJM568]

Thrasher is open loop at idle...The ecm ignores the o2s at idle, and you should too...Don't worry about it...

I ran my fuel pressure at about 38-39# line off...Wasn't worried about performance, just liked the Thrasher for the anti-theft...When I went to the track, I put a different chip in...

 

[GNeric]

I pretty much have the same setup. I have the Poston 107 cam, Blue Tops, ported heads, ported runners on manifold, TA-33, 60mm throttle body, Poston adj. regulator, Poston pump/hotwired, 2800 stall, and soon a 3" home made downpipe. Altitude makes a big difference especially when it's over 100 degrees out. Our track isn't open at night when it's cooler. We have to go to El Paso, TX for that. During the summer here, the air quality is equivelant to near 10,000ft. Sometimes I turn the fuel pressure down even more at the track. While monitering for knock, (0) I have had the pressure down to 32 vacuum line off and still run rich out there. I was running 108 at the time. I would never run this low of pressure on the street with the 91 octane we have.

 

[Scott231]

Originally posted by 6SENSE
Got a Thrasher92 chip this past weekend. First thing I noticed (and wasnt surprised, knowing how our hotair cars are) was that there was no way I was going to run 45psi FP like they say it is IMPERATIVE that you do.
I have been playing around with the FP and now have it down to 34psi static. Still no knock with about 24psi boost, O2s are still around 800 or more! At idle I havent been able to get the O2s down, they are around 700-750!
I like the smoother idle and driveability, but performance has really sucked so far with this chip .

The 45 psi "is imperitive" is an instruction to those with intercooled LC2 motors...not hot-air cars. The Thrashers were never meant to be run in a non-intercooled motor.

You are comparing apples to oranges...