Wondering if this 1/4 time sounds right?

[Arod6692]

Well I have a 87 grand national with a lt1 with a 58mm tb,42lbs injectors, lt4 hotcam kit/ msd opti coil and 6al box, walbro 255, smooth elbow cai, shorty headers, under drive pulley, built 4l60e with yank ss3600 stall, mail tune and mt drag radials. I'm sure I'm for forgetting some stuff. Well I went to the track sat and my best was a 13.3 at like 103.5 I believe. Does that sound right. Only problems I can see is my shifter is a little sloppy and I can't even get it to go into first gear. So I shift from 2-3 only. I tried just putting it in drive but it just launches so much better when I manually shift it. What do you guys think. I believe it's at least a high 12 car.

[popo8]

I dont think thats bad... thats a full frame heavy car.

MEMBER @ LTXtech.com

[Arod6692]

Yeah it weighs around 3500 lbs

[Arod6692]

I was gonna try to get a better shifter a electric water pump and a 100 shot of nos set up this winter. What do you think that would get me down to.

[CamaroZGuy]

sounds about right, but what rear end/gears? and whats your 60ft time?

[popo8]

sounds about right, but what rear end/gears? and whats your 60ft time?

yes...this^^^ first.

MEMBER @ LTXtech.com

[Arod6692]

I have a 10 bolt with 373 gears. I'll have to get my actually slip from the car tomorrow for the exact results. Hopefully you guys can help me get these time time. I also have the suspension all done on the car as well.

[wysemunky]

I'm interested in 60 foots as well. I think the car should be in the 12's easy, I did it at 3450 pounds with just headers. exhaust, stall and CAI on the stock tune. It has the 8.5" 10 bolt correct?

[Arod6692]

No it's just a standard 7.5 all the good parts were robbed off the car long before I got it. Yeah I just feel it should be a lot better for the parts I have. I don't have a bunch of junk on there it's all name brand shit Holley,yank,msd, I've got quite a few bucks tied up in this ltx and it's really not
that impressed.

[popo8]

Also...who tuned it, and what kinda numbers did it see?

MEMBER @ LTXtech.com

[Arod6692]

I have the everything on the front suspension replaced except lower control arms. I have tubular upper control arms 2in beltech drop spindles with drop shocks. All new brakes rotors pretty much everything and the rear I have adjustable upper control arms and solid lower control arms with 1 in beltech drop springs with 1in drop shocks and a air bag in the right spring to stop it from wheel hopping and torquing down on that side.

[Arod6692]

It was just a mail order tune by madz28 I believe.

[popo8]

ok...im def one that believes mail orders leave alot on the table.

Get us the 60'

and also...do u know what it weighs?

MEMBER @ LTXtech.com

[Arod6692]

Yeah I believe the same thing I mean they can only do so much without having the car for
live feed. But the stock weight is 3500lbs. I'll have to get a exact weight on a scale with me in it.

[Mystery Bird]

Something's not right. You should be at least high 12's with hot cam, gears, and stall. Your weight is not much different that a stock TA. What did the LT1 come out of and how many miles? 42lb injectors are overkill but that's not a big problem. Was it tuned after all those mods?

[popo8]

And get us those 60' times.

MEMBER @ LTXtech.com

[TravisMcGill2000]

What rpms are you shifting at? Like already said the 58mm tb and 42 injectors are overkill. You still should be running in the 12s.

[Arod6692]

It was tuned for it all and ECM has it shifting at around 5500 to 6. Kinda floats in there and my 60ft time for that pass was 1.899 and 1/4 13.366 at 101.02 then I had a pass of 13.643 at 99.08 and 60 ft of 1.8. It was all over the board I ran like 6 times. Idk if it's just me getting everything dialed in right or what but I've probably have made over 40 passes in this car from the stock motor and suspension till now. I had a freak pass of 13.9 at 97.89 with a 60 ft of 2.074 on stock motor and suspension

[Arod6692]

I'm running 255 50r 16 mt drag radials. You don't think there's to big.

[TravisMcGill2000]

You need to be shifting around 6300 rpm. The tires should be to big. How are you leaving? You should be pulling 1.6 short with ease. My car liked to be launched around 1500 rpms.

[Arod6692]

That's just what it was programmed to shift at. I'm gonna get a b&m shifter and manually shift it my self. And yeah I was leaving around 1800 to 2000 rpms.

[Injuneer]

What brand shortie headers? ... primary diameter? What does the rest of the exhaust look like? I had JBA shorties with my original "bolt on" setup back in the late 90's, and they sucked. Decent bottom end, but they choked the engine above 5,000RPM.

[Arod6692]

Not sure on the brand but I have 2 1/2 in exhaust into a x pipe with 10 series flow masters and tips. I'm also was limited on the types I could fit. They don't exactly make a header for a gn with a lt1.

[Arod6692]

The headers have been on the motor since day one also. I even believe there just standard 350 headers.

[Arod6692]

The headers have been on the motor since day one also. I even believe there just standard 350 headers.

[Arod6692]

There 1 5/8 primary headers.

[shownomercy]

If its an automatic, why are you shifting it? Isn't that for manual transmissions..?

[popo8]

BTW.. a quick google search shows that the 87 GN in stock trim is 3400 lbs.. so add a few more for the bigger block. You were pretty close.

[JCzNova]

If its an automatic, why are you shifting it? Isn't that for manual transmissions..?

Could be leaving some accuracy on the table...

[Arod6692]

I'm shifting it manually because the ECM shifts it sooner than I want it to. I think I just need to have this damn car dyno tuned and my shift points put up higher

[popo8]

I'm shifting it manually because the ECM shifts it sooner than I want it to. I think I just need to have this damn car dyno tuned and my shift points put up higher

I think thats a great idea.

MEMBER @ LTXtech.com

[Arod6692]

Now the problems going to be finding somebody in my area that can dyno tune a lt1

[popo8]

Check the members map for others in IL and see if they know of IL tuners.

MEMBER @ LTXtech.com

[Arod6692]

Will do thanks for the advice

[popo8]

Sorry thats all I have man. You can also start a thread in ur regional section to ask.

MEMBER @ LTXtech.com

[firebird_1995]

Damn somehow missed this whole thread! My 85 MCSS with me in it (325#) weighed 3595 at the shootout. That was with about an extra 100# on the front end with all the supercharger stuff. Full interior, etc. These cars are lighter than you think. You really should be in the 12's with that combo. Were you spinning at all?

[Arod6692]

No not really when I heat up the tires. It even hooks good on the street.

[Arod6692]

Would my iacs being off affect my 1/4 mile time

[Mystery Bird]

Would my iacs being off affect my 1/4 mile time

Only if it's causing split BLM's.

[shadowbandit]

Please tell me that it didn't have a 3800 in it when u bought it sorry for asking just live the gn

[Arod6692]

Yeah I'm gonna but some spray on it this winter and have a dyno tune done so I get it fine tuned where I need it. And I gotta fix my iac counts also.

[Arod6692]

Yeah I'm gonna but some spray on it this winter and have a dyno tune done so I get it fine tuned where I need it. And I gotta fix my iac counts also.

[firebird_1995]

Please tell me that it didn't have a 3800 in it when u bought it sorry for asking just live the gn

No. He said somewhere in another thread that it was basically gutted when he got it

[Arod6692]

Yeah I didn't see that post thanks for the back up. I started buying little things here and there for my 383 stroker.