top speed run 3000gt sl

[HilbillyHomeboy]

They slow down acceleration. The further the bulk of the weight is from the hub, the more difficult it is to turn the wheels.

Jeremy

[IPD]

power/eco mode doesn't effect top-speed. all it does is change when the TCU attempts to shift the car. pwr will respond faster to downshifts & will go all the way to redline. econ will want to shift ~6200 rpms (DOHC) and will be slower to shift overall.

[stealthee]

Do you have stock tires/wheels? Stock size should be 225/16 for you. Wider tires actually do affect top speed, because it increases rolling resistance (and usually rotational mass.) I have a friend of mine who went from 225/295 tires to 245/315 and his top speed slowed from 202 to 196 (gps verified.) It's going to be less of an effect at 130-140 mph, but it could still cost you 2-3 mph.

Other than that, I'd suggest checking compression as others have stated. I'd also do a run with an open downpipe, sounds like you could have an exhaust restriction sapping power. These cars are old, your exhaust may be rusted out or your cat may be blocked.

EDIT: Wait a min, you say it's a 97 SL... Are you SURE it's an SL? 97 is the year the base Stealth engine became available, and if you just have an SL badge on the car, you're stuck with a 164 hp SOHC engine. In that case, your speeds are right on. Does your engine say DOHC on it?

SOHC will still do 140, barely, but it will do it. Ask me how I know.

[hyper3000gt]

on your sig you say you deleated the egr, what does that mean?

[hyper3000gt]

power/eco mode doesn't effect top-speed. all it does is change when the TCU attempts to shift the car. pwr will respond faster to downshifts & will go all the way to redline. econ will want to shift ~6200 rpms (DOHC) and will be slower to shift overall.

so it's more of an accleration thing then right? the closer you get to red line before shifting the faster the car acclerates correct?

[stealthee]

Exactly what it says. 94/95 can delete EGR and use a resistor to keep the CEL away. I don't like the idea of a EGR, even if people claim they help MPG. I averaged 25-26 mpg daily driving on a car rated at 19/24.

96+ require a little more trickery.

[IPD]

so it's more of an accleration thing then right? the closer you get to red line before shifting the faster the car acclerates correct?

you're still talking auto n/a. it won't accelerate that fast regardless. slap some turbos in there, and floor it from 40mph, and you'll feel the shift difference for certain.

[HilbillyHomeboy]

Exactly what it says. 94/95 can delete EGR and use a resistor to keep the CEL away. I don't like the idea of a EGR, even if people claim they help MPG. I averaged 25-26 mpg daily driving on a car rated at 19/24.

96+ require a little more trickery.

LOL, I'm guessing he's more asking what the EGR is.

EGR = exhaust gas recirculation valve. What it does is take part of the exhaust and run it back through the combustion process. It's supposed to produce a more efficient burn. Realistically, it's just emmissions crap. I agree with Stealthee, I'm not a big fan of them. Be careful deleting it if you live in an area that is subject emissions testing, especially if they do visual check under the hood.

Jeremy

[hyper3000gt]

thanks guys alot of really good in fo here. and turbos might be something I'll do in the futire for my car as I see there is tons of great info on how to do it here. but for right now I'm just going to try to figure out whats robbing me of my base HP and then take it in little steps from there. I might get a high flow cat next or something.

[sketch]

put it on a dyno.