LT's = LESS power
 

anybody else get neg. performance from LT's ORY ngk tr55 plugs and MSD 8.5mm wires.. i did WTF???


lost .3 off the quarter and it just feels slower to me....


this is what i installed

pacesetter LT's "race"
TSP ORY
ngk tr55's gapped to .55
MSD wired 8.5mm
bosch 13111's

i also got rid of the AIR system....


i was throwin a few codes at first and it felt like it had a very slight miss, so i diconnected the batt. to reset the PCM... waited 15 mins and now SES light IS OFF and feels better but still not what it once was....

any ideas besides plugs and wires??... has anybody else had these results?? i want a dyno tune but wana wait till i do a few more non bolt on mods :devil:

what did you do about the o2 sensors?

My car didn't pick up much (only gained about .1 in the 1/4 mile, and less than 1 MPH) until after I did my own tuning. I don't have any new times, but considering it now roasts the tires in 1st gear, and on wet roads it smokes the tires by just flooring it in 3rd gear, it should be much more powerful. My guess is the tune is off...some cars don't respond well to LTs simply because the PCM doesn't like them.

He listed what front O2 sensors he runs (the Bosch 13111s), and it wouldn't matter what rear O2 sensors he runs (if he even does). The rears have no impact on performance whatsoever, even if the PCM is throwing codes...

ya... i have the bosch 13111's corvete rear o2's up front as listed and no o2's in the rear.. i hope it is just a tune but i dont feel like dishing out 500, but i guess i will in 2 weeks or so...

im gonna pull the plugs tomorrow and check um out..

Give the pcm time to halfass tune it self .It will never be as good as a permanent tune but it will get better .

It might get a little better, but at WOT, it won't be any better really. The stock tune is set to be rich as all hell from the factory...

I know my current has more potential power in her if she was tuned, but i'm happy that I still gained a few mph and .3 tenths without a dyno tune. I'll tune her when she starts making some more lift & duration hehe.

Are all the plugs and wires in tight?

Amen brother mines killing bugs currently .. I see them fly towards the back of the car then down to the pavement stunned :owned:

You need to tune it.

That's odd as I went from 13.6 to 12.9 with LT's, TD's and a lid. My MPH went from 103 to a highest of 108. This is without a tune. Perhaps I'm just lucky. I'll be getting it tuned in the near future. These mods were all done at the same time and it was a very noticeable gain by the old butt-meter.

+1 for the tune. That is def what is killing you. When I got my tune it was night and day. I got around 20ish extra h.p. and a butt load more t.q. Look around for local shops that can tune it or maybe regional forums for someone with software. I got my tune for $200 they deleted the rear o2's,skip shift, tq mgmt, adjusted the air to fuel and messed with the spark. She'll stop bein a whore when you tune her.

Go EFI Live and tune it yourself, buy it once and your set. You can tune it whenever you want after that. Or send in your PC for a cheaper tune, they usually do a pretty good job for about $200.

My buddy went to "race" Pacesetters, ditched the cats, and had a similar result. The car felt really sluggish at first. He initially installed them with some TD's he built, then ditched those for an ORY and Flowmaster, and it felt better. Then he changed out to a Hooker, and it felt better still.

With a stock cam and intake, these cars seem to respond better to a little more backpressure. It definitely makes for better throttle response and low-end torque.

The other factor, as everybody has mentioned, is tuning. His car is really lean. Once he gets his AFR where it needs to be, it should be a lot stronger.

I felt like mine lost some low end torque with LT's and ORY. Although, I definetly gained in the higher RPM's

It seemed that my car felt the same way after the LT's went on. After driving a few days with no tune it seemed to get much better, as well as idle better also.

Like suggested, you may want to drive the car for a few days and let the computer make some adjustments. Then it if continues to run worse, start checking for problems from there.

with lts, some cars get really rich afterwards killing any performance that they would have gained. most shops charge 400-500 for a tune, but if you need a retune, such as after a cam, they'll charge less. Do you see any black smoke when you go WOT?

Even with stock heads and cam, I don't think it really needs the back pressure if you know what you are doing with the tune...mine runs stronger all over with no cats and only bullets in my duals.

I showed no gain in E.T. untill after the tune.
I'd get it tuned you'll see a difference and a dyno tune is not a must.