Lt1 performance ?

Exgmguy

Exgmguy

Club Member
I took my 1993 Z28 to the track a couple weekends ago. I made 3 quick passes and never really let it cool down. All 3 passes were 13.6 @ 102 mph. My 60 ft's were 2.0's and my 1/8th mph was 84. Toward the end of each pass my check engine light came on, giving a "fuel lean monitor" code. I took off my fuel filter and it was so clogged I could barely blow any fuel through it. Shouldn't an 84 mph 1/8th equate to a around 104 trap? I changed the filter and the car seems to run better now.

I am also wondering what parts I should get next. I would like to keep it to cheaper bolt-on parts as well. The car is an auto with a shift kit, stock 235 tires, stock converter. I already have an old school Hypertech chip, 160 thermostat, new plugs and wires, Moroso cold air kit, air foil, 3.73 gear, SLP headers and an Edelbrock cat-back. Pretty basic. I just put on a BBK underdriven crank pulley, and was considering 1.6 rockers, a custom tune, and maybe a larger throttle body. Maybe a decent converter and some drag radials along with these parts might get me there.

I would like to get it into the high 12's without using a nitrous kit. If I find a deal on a Powerdyne kit, i'll hope to go that route.

There were a few other LT1 cars at the track that day with a lot more parts running high 13's and 14's @ 101ish. I don't want to end up with a car that gets slower the more parts I throw at it.

Thanks!
 
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Funny thing is that I would not even spin off the line. On the street it won't either unless I power brake it. If I floor it off idle, it just goes.
 
cam/headers/rr's

really, pick up a used cam and set of pro mag 1.6 rr's, and some edelbrock shorty headers, money well spent..
 
"I don't want to end up with a car that gets slower the more parts I throw at it."
Welcome to the world of modifying a car. If it were as easy as throwing a part on a car and going faster every time than everyone and there brother would be doing it. The fact is that when you modify your car chances are you'll have to trouble shoot after you install it. Unless you have a reputable shop install all of your parts for you, but what's the fun in that. My first time out to the track, after spending a couple grand in my lt1 I could only muster a 13.9@103 w/a 2.3 60ft. Pissed me off pretty bad but there was also a lot of stuff that had to be fixed on it. Slowly but surely I kept tweeking/modifying it and the next time out it went 13.0@109 w/a 2.2 60ft. It should've gone mid-low 12's but like I said if it were easy everyone would be modifying cars. Fact is, it's not. Just keep tweeking with your car and it'll start to come around.
 
How hard is it to change the cam in an LT1? And will my ecm flip out considering it is speed density? I don't know about GM engines, but earlier speed density Fords don't like a different cam.
 
3000-3200 stall and some MT DR's in 255/50/16:D that's my vote if there's a poll or something I didn't see.
 
Would look at a new fuel pump and a converter like autoroc said
 
I will definitely get a good converter and some tires. Loose auto's are the cats ass. :)
I want the car to stay driveable though. Cold air, good handling, and reliable. I am pretty good at getting a perfectly driveable car and making it annoying to drive anywhere but the track.
 
Converter did wonders for my LT1 car. Give you a tip. If you get a cam dont get the LT4 Hot cam. It is a boring cam and you will not be happy I wasnt. If you want a good running LT1 talk to Sean @ C.A.R.S. he did mine and it has never ran better.
 
My LT1 combo

I have a similar combo but with the "boring" hot cam and it runs 13.30s at 106 with traction issues. FWIW it idles like a stocker.
 
wtf

limige said:
cam/headers/rr's

really, pick up a used cam and set of pro mag 1.6 rr's, and some edelbrock shorty headers, money well spent..
Click to expand...

edelbrock shorty headers are u shitten me thats the most horable idea ever...fuck short tube headers....put a fuel pump in the car with a 3000+ converter.....electric water pump...exhaust cut out after the y pipe...i believe u can get comp engineering drag shocks for cheap(remember u get what u pay for) not the best but they do help and don't cost a million dallars...dump the a/c off the front... put some good 1.7 roller rockers on and a GOOD dyno tune and you should go 12's.....then if u play a couple other things right with a camshaft swap u should be able to touch off 11's oh yea and some good tires :)
 
Losing the a/c is definitely not an option. Neither are drag shocks. I am not going to "strip" this car out. If a cam is a fairly easy job, i'll probably put a better cam in it, or just 1.6 rockers/springs for now, a converter.

Is the stock throttle body a restriction at the bolt-on level?
 
52mm BBK Throttle body is a good bolt on.

Sean



Exgmguy said:
Losing the a/c is definitely not an option. Neither are drag shocks. I am not going to "strip" this car out. If a cam is a fairly easy job, i'll probably put a better cam in it, or just 1.6 rockers/springs for now, a converter.

Is the stock throttle body a restriction at the bolt-on level?
Click to expand...
 
yea i can see not doing the shock but definately a good converter and a good cam...(not the hot cam pleassseee) but if u do a good cam ur ganna need some valve springs and pushrods...
 
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