Recently bought a 94 LT1 and was looking for some suggestions for cheap ways to gain power, pretty much only aftermarket ‘mod’ on it is the typical muffler deletes but still has stock cats, I’m considering deleting them and doing some intake work and maybe a cam but want to get some suggestions on what will benefit me most to get more power as well as what kind of cam would best suite this engine without having to do head modifications, also looking for suggestions on good tuners. I would like someone who’s trusted and has a solid background with tuning. If anyone’s tried cold air intakes like the SLP tri flow kit or anything similar did you notice any sort of difference with it? Is it worth it?

 

Wish newbies would put information that would help us help them. What is your location? That will help people direct you. What is local to me might not be to you.

Most important question. What kind of money are you willing to spend? After knowing that, we can subtract for incidentals and figure out what you can accomplish. What is your goal? If you want to make 500HP and spend $5000, it isn't reasonable. Money dictates how much of the goal you can achieve.

IMO, there are 2 ways to get tuning. "Guess a tune" where you tell me what you have and I guess what to write you or running it on a dyno and squeeze out the best performance. Obviously, some road driving would have to be included since it is also driven in other areas besides WOT. That isn't cheap. Nothing good ever is. If they tell you they can write you a chip and have you eval it with the butt dyno, IMO, it is "Guess a tune". Datalog to fine tune it, sure.

As to what combo, I think you are going to need to speak to the tuner. I can give you my top end combo but it might not work as well with your stock bottom end since it has to work as a system. This isn't a boob job where you can put a fantastic set of ***** on a "2 bagger" and have her turn into a hottie.

Cold air kits, if you feel a difference is is mental. Unless you think you can easily test say 10HP

 

There isn't a whole lot thrifty performance mods. Open air filter and tbi foil maybe 8 hp. Corvettes use high flow cats deleting them isn't going to net a much. A4 cars will get more noticeable performance with a gear change than engine work. The 94 and later LT1 PCM requires reprogramming vs chips.

 

Headers, put some mufflers back on so you can live with the sound, leave the cats. CAI won't hurt, but it won't help much. Try to find a 3.54 loaded rear end and just swap it rather than changing gears. Seems to be a bit cheaper. I also agree with the air foil, not much of a gain, but won't hurt and it's cheap. After this, an adjustable fuel pressure regulator, and bump the fuel pressure a few PSI. The little basic bolt ons won't affect the tune much, but the added pressure will give the ability of the injectors to flow more fuel if need be. You could have the intake manifold ported a bit and polished. Before you do the cam, just get some 1.6 Roller Rockers. This will give you more lift with your existing cam.

A cam won't be cheap. On a C4 it is recommended you pull the engine to do the swap. So, your cheap modifications end at the above as far as I know.

You really need to provide a budget and goals. After the above mentioned mods, a tune would help but it's not going to be mandatory. You could just find an old Hypertech or diablo hand held tuner, not load their tune, but use it to correct the rear gear ration for your speedometer. If you do the above, you would be amazed at how different the driving experience will be with the change in sound and the better response with the new gear.

If you want a proven cam that doesn't require much modifications, its hard to be the LT4 Hot Cam for general street use. It is a 218/228 Cam on a 112LSA.

 

The expense of swapping to a 3.54 gear ratio depends on whether the OP's car is an A4 or a stick. If an A4, the OP would have to do the entire Dana 44 swap. Dana 36's with 3.54's in them for sale are like hen's teeth.

You don't have to remove the engine. There was this here on the forum.

https://www.corvetteforum.com/forums...n-your-c4.html

If you click the link about the writeup in the above link, you will notice that website is long gone.

I had to enlist the services of Sherman and Mr. Peabody and go back in time via the Wayback machine and recovered this write up. Has plenty of pictures. The author did a great service to show folks how to do it with the engine still in the car. A picture is worth a 1000 words and his write-up has plenty.

https://web.archive.org/web/20050307...ps/hot_cam.htm

Here are all that was on that site for techtips that was captured. Take notice that it contains captures of the pictures as well. They end in .jpg.

https://web.archive.org/web/*/http:/...com/techtips/*

 

Cheap & Performance should never be used in the same sentence because it can never be realistic.

 

If it's a A4 the standard gear is a 2.59. Just going to a 3.07 would be a vast improvement. Label under console door lists RPO codes G92 indicates performance axle. GM1 2.59 G44 3.07. 94 M6 use d44 and only 3.45.

 

I'd pass on this myself. If it is within a small window of adjustment where the ECM can easily compensate without much change it probably isn't worth doing when you can have so much more by spending a bit more. You have to R&R the motor anyway. Might as well fluff the heads and do the cam all at once.

 

Cheap, fast and reliable. Pick any 2. I've found I can't afford cheap.

 

Here is another thread where... "What are some basic not too wild or expensive things I can do" is the question and it slowly ends up in pull everything apart. Soon an LS swap guy will show up.

The LT4 hot cam is well proven and worked out in many set ups and can run on the factory ECM. Not that it couldn't be optimized, but it can. Sure there are better cams depending on other components of the combination and tuning.. but eh... the LT4 Hot Cam has been a solid bet for over 20 years.

Why not fluff the heads? - well because more expense and labor. I mean hell, if the cam is out and heads are off, why leave the dang short block in the car. - Once it's out, why not replace the rotating assembly and go 383? Why use a cam that doesn't actually require a tune when you can pay for the cam and the tune? Sure would be a lot easier to pull the cam/heads and install headers with the engine out. Why fluff the heads when you can go to a set of AFR 180's?

If the engine is out, why put the SBC back in. Go LS7.... better yet, New LT4 and just call it done?

I don't think the OP was looking to spend that much or get a wild combination.

Again I say, we need stated goals. Or if OP wants a peppier car with a little more SOTP excitement... headers, gear and then see where you want to go from there. Mild to full on race car is available depending on what you want to spend and tolerate.

 

This is true, spend money on good components. Stay away from Ebay and China sourced crap.

 

I fixed the above link to the cam install. Here it is again

https://web.archive.org/web/20050307...ps/hot_cam.htm

If you want to find websites that are gone, do a Google search on Wayback Machine. Go the the web archive website, put the site you are looking for in. It will show you when captures of the websites were done. Depending on how the site was built, it may or may not have what you are looking for.

I was able to rescue some write-ups for another forum member using the wayback machine.

 

Hello there Mr Parker and welcome to the world of C4. The honest basic answer to your question is that for a late model LT1 C4 there are not any inexpensive mods that will yield "significant" performance increases.

If your engine has not been modded to the point where you are putting out the volume of exhaust for 400 RWHP your stock dual exhaust really is not restrictive. Taking off the large factory cats or the mufflers will increase noise but that's about all.

If by chance your car is an automatic like mine, the biggest gain for the buck is a rear gear ratio change. Many LT1s came stock with a 2.59 Dana 36 rear end. There was a popular $50.00 option to order the car with a better performing 3.07 Dana 36. There is a very noticeable Seat Of The Pants difference between the two. If you have the 2.59 rear I would suggest that you seriously investigate swapping out for a 3.07 which are easy to find as many people swap out the Dana 36 for the more stout Dana 44 that came with the MT cars (people who invest the $$ to increase the stock RWHP will opt to switch out the D36 for a D44).

You need to think about what you want to accomplish with your C4, how long you intend to keep it and most importantly how much you are willing to invest.

As far as good tuners for your car .... I live near one of the best in the west ......... but we don't know where YOU live.

 

I live in central NC, I don’t mind using a tuner who would email me a tune as long as they are a trusted and proven tuner, there are not many dynos or tuners near me that I am aware of, I plan on keeping this vette for a while and in the long run I do not mind spending a bunch of money on it however I want to start off slow just doing the basics and cheap and easy work to do. I don’t want to just pull the engine apart and start swapping everything or try and turbo it or anything crazy like that right now I just want to give it a little more power but still budget friendly until I decide what kind of direction I want to take the car in, as in reliable but quick daily driver or just full race car and swap all engine internals or even LS swap.

 

Maybe it is just a rabbit hole?

If it is close to stock, it probably will be workable. Didn't say good enough to justify the mechanic's bill but workable.

Hard to say. Perhaps you are right. Just leave the cam alone until you are ready and able to spend the money to justify the cost.

 

The car is pretty well optimized as-is. Meaning there's not a lot left on the table with the existing hardware or cheap bolt-ons or even PCM tuning, but if you're willing to do a cam swap then things change.

Being a '94 you can tune your engine yourself with a cheap DIY ALDL cable, TunerPro and EEHack.

As your '94 has a mass air flow sensor the PCM really doesn't benefit much from fueling changes as it responds to air flow improvements (within reason) automatically. Some gains can be made with ignition advance tuning, but this needs to be conservative. The LT4 hot cam (and a valve spring change) is within the original PCM's fueling range, but some ignition advance changes are helpful.

As others mentioned a gear change is a big deal if you're starting with 2.59s.

 

Hack part is right. It takes way more than a laptop and a cable to really learn to do something well. Just because I buy myself a chest full of tools doesn't make me a mechanic.

 

EEHack is a free software tool that does data logging, re-flashes the PCM and more. If you don't have an interest in that, or the original poster doesn't that's fine. Some may and for those folks I will continue. For $20 in parts I built a cable and have been learning plenty about my car.

As a novice user I've learned that most of my fuel trims are adding fuel. I can see the O2 voltages and see that they are switching, but since they're 25 years old I'm going to change them and do more data logging to see if it was worthwhile. I see the TPS responding smoothly, the MAF is responding well, I can command the cooling fans on/off, I can command the AIR pump on/off. There's a lot more: http://fbodytech.com/eehack-2/eehack-features/

 

I don't doubt the features. I doubt the operator. Let me explain since I THINK you didn't get what I was saying. The software can do all kinds of things. Whether the operator can make it do the things is another story. From personal experience so YMMV.

I have a 7.3 Powerstroke. After a bunch of mods, I got a datalog sent to the professional tuner. It took several tries before we got this spot on. They do about 3 to 4 a day for "dyno day tuning". Figure about a couple hours. Last time (a couple months ago), it took us several tries and a bunch of runs datalogged before we got a single issue fixed. Pedal was so sensitive that it kept revving the engine when we were on rough terrain or even bumpy roads in town. Somehow, this came about immediately after I changed the pedal assembly with the TPS in it.

I have done my C4 twice on a dyno using what the tuner recommended as a setup and it took a couple tweaks before I was OK with it having most of the rough spots worked out.

On my F-body with Linfenfelter using the Superram he designed and the Tri-Y headers he sells (he should have gotten the program down by then), it took a couple hours of time between his testing and burning the program onto the chip to get it fine tuned.

How long do you think it took them to learn that skill? Nowhere as easy as mastering the software, I'll bet. Bottom line, I think that while you can understand the software and how to make the tweaks RELATIVELY quickly, I think getting the nuances of tuning is going to take a very much longer time. For a race team, it is worth the investment. They make changes from day to day. They have a much larger wallet than I do since I don't have sponsors. Taking the average person, I can haul my car 6 hours away, have it tuned on a dyno, stay overnight and be back before they fully master the software, not to mention the tweaks. So unless you are doing enough of it, have access to a dyno to see exactly what does what and lean from it, getting someone to do it for you is going to be more efficient That is why I said it would be a hack job. Ask yourself this honestly. How much time have you spent so far and how much more time before you think you are as good as a professional who has been doing this for a while?

 

No, you I get. You've told me plenty about yourself. You don't seem to understand that I disagree with you.

I invested less than 1 hr of shop labor rates to buy the factory service manuals and then spent a few hours troubleshooting my AC control problem. Blessed be the working AC!

I built the ALDL cable to see that despite CCM diagnostic mode showing me "err" for module 4 that I don't have any PCM DTCs. What I do have is CCM code 81 because the CCM was programmed incorrectly. I'm currently hunting for a Tech 1 or 2 so that I can fix what the local Chevy dealer could not.

Education is much less expensive than ignorance.