My 93 Lt1 seems slow,
Accelerate it seem better depending what speed I’m going when I hit gas, and other times its just a dog when I nail it! Performance seems lacking it’s even hard to break the tires loose! This normal power for the lt1 engine? The corvette runs good it has a new gm optic spark when it warms up it will idle little rough in drive

it's a 93 coupe auto,

 

What rearend gear do you have in it?

They were only 300chp from the factory. They ran good but werent tire burners

Is it in proper tune, no codes?

 

it runs good no codes, i'm not sure but i think it has the 2.59 gears

 

Without knowing more theres the problem those things suck for accelration.

Throw some 3.45s and a stall converter at it, will be a totally different car.

 

Biggest problem with performance.
Stall, gear will wake your LT1 up.

 

You can find out what gear came in the car from the label inside the console door. GM1= 2.59 GU2= 2.73 G44= 3.07 GM3= 3.45 (6-spd. only)

 

Just checked my label and yes it has GM1= 2.59 gears so is there any thing good about 2.59 gears? If you change the gears wouldn't the Speedo be off, and would the computer needs to be reprogrammed for the new gears or no? I don’t under stand about the stall converter how it works to make more power?

 

A higher stall will bring the engine up into the power band before the converter locks up and the car begins actually moving. For instance, the C4's came with a 1400 RPM stall from the factory. If you move up to say a 2600 or 2800 RPM stall with a better set of gears (maybe 3.73's) you are going to see a huge difference in acceleration. Stall speed isn't the whole story though. Google "stall torque ratio" and read up on that topic as well before making a decision. A smaller diameter converter will help you as well as less inertia is required to actually spin the converter resulting in less parasitic loss from the drivetrain. I currently have a a several LT1's that i've built and they make great power when built properly. One of them is right at around 550hp and I run a Precision Industries Vigilante converter with a 3200 stall. Of course I have a rather large cam so the higher stall is necessary but that thing has eaten quite a few C6 Z06 lunches on the streets. One HUGE thing to look at with the LT1 (as with any engine) is how well it breathes. To improve things start with a CAI and good exhaust and you'll see a big improvement. Once you have this in place take a look at your power band and decide on what you want to do and start looking at torque converters. I have pretty much all the LT1 information you could ever want so feel free to ask me any questions you may have. Oh, and yes, you will need to have your computer reprogrammed for a new gear set to correct the error. 2.59's would be fine if you had a 750hp forced induction machine but even then you can do better. You can go with some 3.43's and still get good gas mileage and achieve better acceleration. 3.73's would be even better.

 

My stock L98 will light the tires up just stepping on it, and my LT1 camaro, when stock would also....

I think the OP should look into if there are any codes (as mentioned above), and do some checking to make sure its making all 300....

 

RR...easy does it...get it to breath better, better incoming air..try a K&N, a larger bore
MAP kit, bolts to the space your stock one does improves cfm, check your throttle adjustment cable, have your tps sensor, and MODULE checked, the old module gets wet, and throws a blanket on your dance...its located in the right hand fender below the radiator fill tank. I have 2.59 gears and I can chirp them at will..with my stock lt-1. with some air mods, for low bucks, what could also be happening is in your trans..depending on how your shifting works, mine is hydraulic, and I had to have the 1/2 and 3/4 shift solenoids replaced. your car, 93 may be a mechanical adjustment, for your shift points.
I would not recommend you diving into a tranny drop for a converter nor a rear end change, as you can bring a huge amount of cash to that effort. If you are going out to race..my advice is nil, I would save for a nice cat back, to get a balance in the air in air out, and check the trans shift points, and your intake. try easy steps, that you can handle in your own garage, before someone decides, hey lets drop your exhaust, your tranny and your whole rear suspension to get at the pumpkin, and hand you a 3 to 4000 dollar bill. best investment? Factory Service Manual, and read about every system in your car. rough idle, could be many things, check tps, module, IAC, but not until you completely understand what each does, in closed loop, open loop, EGR and even PCV ...can affect your idle. including exhaust leaks..so see, it can become a can of worms.
if you methodically walk thru, you will isolate each problem, and solve each one, the move on to the next, that's the fun of owning an older vette.

 

Is there any stumble/hesistation? or just inconsistent performance?

Stumble/hesitation are well known issues when an opti-spark goes bad. It causes stumbles/ hesitation when under load. Such as up a hill, and when hot.

I know he says he has a new one in there.

Maybe try new plugs and wires also (stay away from any of the MSD wires. they are garbage).

Also, these cars have a noticeable drop-off in performance when hot vs. cold. Be aware of that.

 

Popo8 is absolutely correct. Check for any codes and then go from there.

 

Yeah, definitely good point here also. I do all my own work so it's cheap (relatively speaking) for someone like myself to go the route of popping in a converter or a set of gears but if you're not willing/able to do the work yourself you're definitely going to drop some pretty decent coinage on work like that.

 

 

Small mods like those for the air intake or cat back won't do a whole lot but empty the wallet quickly. You can get 15-25hp from headders but it may cost you $600-$1000 when done.

First find out why it's running rough and re-adjust your throttle cable. If that doesnt do it for you look for a good 2800-3200 TC, headders, new gears, custom cam and heads. For the biggest increase look into a stroker build or power adder(N20, Turbo, SC).

My personal preferance.. A complete nitrous kit with all the saftey stuff will cost around $1000 and $40 a refill. but you will see 100hp at the wheels. Your problems will go from "how do I break the tires loose" to "how can I get more traction". Best bang for the buck out there.

BTW my 95 3.07 geared auto ran 13.5 completely stock and would break the tires loose but it also moved forward at the same time. Breaking the tires loose is not a good thing, IMO.

 

Come again? In english please.
Large bore MAP kit??
Bolts to space your stock one??
TPS MODULE?? Under the fill tank???

What are we talking about here? This is gibberish and if its the "mods" that I suspect your trying to articulate, those mods don't do squat. And they certainly won't turn a 2.59 geared LT1 into a tire burner.

The OP needs to get to the track or dyno to confirm his SOTP meters assessment and see what the car is really doing.

 

Boy are these cars getting cheap.

 

 

 

Tom, misprint, and I agree, secondly...it is not gibberish, thanks. I am talking to the guy about increasing the cfm intake in an lt-1 via the connection between his air filter and his MAF, sorry..fd' up the MaF and MaPressure..yeah i know, I am Not trying to get him to be a tire Burner..damn..he seems like his car is definitely out of throttle adjustment, and slowwww..ie..all the freakin steps I had to do, to put my lt-1 back into normal working order. and yes, sir. mounted to the side of the car on bracket, below the elevated tank, there is certainly a TPS module, with a circuit board inside it. I know i took it apart, cleaned the crap out of it, and soldered new capacitors into it. because it completely fried my ASR control, and the car was all over the place hunting for shift points. Doing Squat? hey my car functions fine for me, breaks em loose, normally. I am not recommending the guy do severe mods without first knowing what kind of coin he has to toss at a situation,(although that's not really my business/problem) nor if he knows his way around a tranny or a rear end. and yes, I speak mechanical engineering english. and third, i do agree with your assessment, that he should have the car dyno'd to determine his baseline, sorry don't mean to sound aloof, I appreciate you kicking my a..for the maf vs map..sorry to the OP also. Best, Derek