cam, ported heads, and lt headers will make power with your lt1 and current Throttle body.

Since you have an A4 swapping in a D44 from a M6 car will wake the car up since the stock rear gearing is set up for gas mileage not performance.

Why would you need a short throw shifter for a computer controlled automatic?

If you want to bring your C4s performance up to modern sports car levels you will have to work on your car holistically. (suspension, gearing, braking, power, exhaust, etc)



IMHO the folks at AI have LT1 packages that are second to none.

Good luck


Mike

Too bad the signatures don't show anymore here's mine for a dd 95, and its been in this configuration for YEARS........

Polybushings front/ banskis, DRM brackets rear
Dana 44 w/ 3.45s
EM LTs, 3" B B stainless exhaust still sitting in Garage
AI 200CC full CNC ported heads with upgrades
AI custom cam .615 lift and more duration than the pundits believe necessary
AI hardened guideplates and AI pushrods
CC PROMAG 1.6 NSA,
ATI super damper
3500 Stall
Mezierre HD
58MM TB
Ported Intake
Racetronix Fuelpump and wiring upgrade
Tuning by ED Wright
Thousands in ETCs and OH BUY The Ways

 

IMO (for what that's worth) the best place to work on these old cars is to freshen up brakes, suspension, and if possible put the thing on a diet. The LT1 engine is a very reliable unit as is and will hold it's own just fine if the systems around the car do their jobs. Regardless of mileage everything on the car is OLD; if you could drive an actually new (as it left the lot all those years ago) version of your car you would be shocked at the difference in how it drove.

If we are talking performance for stoplight to stoplight stuff you bought the wrong car...if we are talking about what sports cars actually are designed to do, if you can make it stop, and turn first rate the HP number isn't much of an issue....just my .02

 

Thats just a list of popular mods that people do all the time. Just because it is popular does not mean that it actually works. IMHO I think it is a waste of money that could be spent on something better.

 

Point [finally] taken!

 

I'm not qualified to answer your questions or anyone on this forum. I have an LSx in my car.

Joking aside Vader is one of the most knowledgeable members we have. A lot of member here know a lot about cars you dont have to own a particular engine to know what works. GL

 

Best bang for your buck would be a gear upgrade. It's one thing I did that really made a difference and the proof for me was quicker times autoxing.

 

From my experiences and research you did one of the best mods which is 1.6 RR
Long tubes would be a nice addition. But since you don't want to do that, really power wise I'd say high flow air box, and a hot cam if you want to go into it that extensively.

The air foil and enlarged throttle bodies, maf, etc don't do alot. Someone I had met on here showed some dyno results with those mods and had marginal gains.

As said before a better gear ratio would help quite alot too
Eve. Close to stock might not hurt to get it tuned as well

 

But if your going to cam the car, you should be adding headers to complete the breathing process.

 

I have done almost every mod you can do for this car, and what I have learned is that when you mod something, it affects the entire system. If it's horsepower you're looking for, have the heads ported and add headers through to a good exhaust system. I think Corsa is probably your best bet. Your heads could probably use a valve job after all these years anyway. Go ahead and cut the fins off the air lid, and add a good filter. It's not much for horsepower, but it won't hurt anything either. Don't mess with the MAF, unless you want to risk getting debris in your intake.

If it's seat of the pants feel you're looking for, go with a higher gear ratio. Check yours first, there were different ones throughout the years. 2.53 was a popular LT1, and it is for top end, which is just silly for the daily driver. Throw in some 3.23s and you'll feel the difference immediately. Next step is a new torque converter. Check out vigilante.

My suggestion is to just start with a refresh - plugs, wires, opti, vacuum hoses, PCV, EGR, O2 sensors, etc. Then see if you're happy.

When it comes down to it, you either will keep it stock and clean, or you will be like most of us on this forum, and mod the heck out of it until you have no money left.

 

Here is a list of all the things I did last year. Mine is a 96' automatic with 59k miles on it and the 3.07 rear. Of all these the ones that made the most difference in seat-of-the-pants feel were the O2 sensors and the Injectors. The car now feels like it did brand new. If you want the most out of yours then at least do these two items. Most of what I've done was for reliability, road comfort and handling. Unless you are at the track every weekend the stock car is pretty good on its own.

Banski Trailing Arms
Banski Cambor Arms
Banski Toe Arms
DRM Trailing Arm Mount
QA-1 Single adjustable shocks (Front and Rear)
Spicer U-Joints
Calpers (Front and Rear)
PowerStop Drilled and Slotted Disc (Front and Rear)
Ceramic Pads (Front and Rear)
Stainless Steel Brake Lines (Front and Rear)
Speed Bleeders (Front and Rear)
Polyurethane Bushings Front and Batwing)
26mm Rear Sway-Bar (Solid)
Heim Link for Rear Sway-Bar (C5’s with Homemade Adapters)
28mm Front Sway-Bar (Solid)
Sway-Bar Frame Mounts (Front and Rear)
WBI Tapered Rear Bearings
Timken Front Bearings
OBX Cat-back Exhaust
Continental Extreme Contact Tires
Front Spoiler
Right Interior Door Panel L-Bracket Fix
New Weather Striping
New Roof Panel
New Visors
Clean Electronic Climate Control Switches
O2 sensors (All four)
Fuel Injectors (Bosch III’s)
Fuel Pressure Regulator (Aeromotive Adjustable set for 47psi)
Fuel Rail (C4 Stainless Steel)
Fuel Filter
NGK Iridium Spark Plugs
PCV Valve
PCV Connection Hose
Belt Tensioner
Tensioner Pulley
Idler Pulley
Belt
Air Filter
Clean Between Radiators
Strip and Polish Wheels
Compound, Polish, Seal, and Wax Entire Car

 

Thanks, Klyde! Your two suggestions are now at the head of the list. If I may...

1. Where did you get your Bosch III's, FIC?
2. Did you stick with stock 24 lb. injectors?
3. Did you change all four O2 sensors and whose O2 sensors did you use?
4. Did you change the injectors and the O2 sensors at the same time?

Many thanks for your insights!

 

Yes. I bought the injectors from FIC and used the 24lb ones. Got the rebuilt ones for less than $200.00 for the complete set. As for the O2 sensors I used these from Amazon:

http://www.amazon.com/s/ref=nb_sb_no...xygen%20Sensor

Great price and worked perfectly. I also replaced the fuel pressure regulator with an Aeromotive unit because my old one was about 38lbs and two new regular units were reading about the same. I have the adjustable one set for 47lbs which I believe is slightly above GM's recommended pressure. I replace all at the same time and did a reset on the computer.

To reset and relearn just disconnect the battery for ten minutes. Start the car without touching the gas pedal and let it idle for five minutes. Next take it out and go through the gears a couple of time. Then take it out on the highway and hold it at speed for five minutes. This lets the computer relearn the correct fuel mixtures with the new signals coming from brand new O2 sensors and the more efficient injectors.

So far I am really pleased with the results. The original injectors had the wrong seals in them for alcohol mixed gas and go bad over time with modern fuel. The rebuilt Bosh III's from FIC have the correct material for todays gas. I personally think the Injectors, O2's, and Plugs should be replaced every 50k miles. As for the plugs I used NGK Iridium ones so I won't ever have to replace them again. They took five hours for me to replace and I had to remove the passenger side inner fender well to get to the rear ones.

 

I am considering the following and would appreciate input from those of you with LT1's who have affected these mods. I'm not trying to turn my LT1 into an LT4, just to get the best performance out of what it is. Brand suggestions would also be appreciated.

1. TPIS air flow streamliner for the stock 48mm throttle body or...
2. TPIS 52mm throttle body w/ air flow streamliner

I have used the air flow on a stock TB and on a 52mm. On a stock motor and one with a hotcam , reworked heads and headers. The result is no difference I could feel, or see at the track.



3. New Double-Row radiator (for increased cooling here in Florida)


I installed a champion radiator I got off of ebay. About $200.00 Seems to work well. But to cool your car down, you need to change from the factory t-stat of 180. (yes 180 is factory on a LT1 due to reverse cooling design) to a 160. And have the fans reprogrammed to come on sooner. Make sure you get a LT1 t-stat. It is different then the SBC stat.


[B]4. Unrestricted air filter cover for stock filter (I don't like K&N's)[/B


I cut the top out of my filter box, and have used the K&N. Again no noticeable increase.

5. Throttle body hot water bypass

I did this as well. Makes it easier to work on, but no increase in power.


6. Possible exhaust mods but... I don't want headers.

If you don't want LT headers, there really is no gain on a LT1 to amount too. Now I know this is argued a lot on here so this is my opion. But even if there is a slight gain, it will be in the very upper rpm range and very brief.


7. MAF replacement or mods.

Don't have one on my LT1. But I doubt there is any gain.

Also... does anyone sell an upgraded, short throw shifter for the 4L60e?

I don't believe anyone makes an aftermarket shifter for the automatic c4 vettes. And again, IMO all the ones I have seen that people have made fit, just don't look good. Again my opinion.




In my experience with the LT1 c4, if I had it to do all over again, this would be my suggestion for mods.

1. find a d44 rear, batwing, and c-beam and upgrade. If its out of a 92-96 it should be a 3.45 gear. This is the best single mod to do, IMO I orig. went to a 3.54 and loved it. But the d36 will not take much abuse, and that is the reason I suggest to go ahead and find a d44. This mod alone, especially if you have the 2.59 gear now, will make the car feel like a different animal.
You can reprogram the speedo to correctly read, and at that time have the fans reprogrammed as well. I would contact pcm-4-less about doing this. Alvin has provided excellent service in the past for me.
2. Change out the converter to a higher stall, and get a quality converter, ie yank, vigilante, etc. Stay with a small dia. 9-10 in. and I would go 2800-3000 stall.
3. Go with a better head, cam package, get something designed to work together.
4. You really need LT headers. Otherwise you will be leaving 30hp or so on the table. Again, stock exhaust is fine. I made 362rwhp, about 380 tq. with a stock bottom end, 48mm tb, stock exhaust, but I had a hotcam, reworked heads, and long tube headers.

Good luck with your vette. But as others have said, most of these bolt ons really do nothing. The roller rockers, which you already have, and a set of LT headers are about it short of going inside of the motor.

 

The very first thing I'd do is go through the suspension, if you haven't already. Even if the car is sitting at the right height and "feels good", if you have original parts on there, they're worn out. Even if the car has like 5 miles on it when you bought it, the rubber is shot at this point. Bushings, shocks, brakes are a great start. You'd be amazed at just how much better the car will corner with those replaced and or upgraded. If you want to get really crazy you could add a VBP Sport Spring, and upgrade your sway bars later.

Now as far as engine related goes...

Coolant bypass would be decent for a florida car for cooling I guess.
Double row radiator, I definitely recommend. I bought a Dewitts double row for my 89 and don't regret it even slightly. Much more cooling capacity than stock. That being said if you aren't overheating, just moving down to a lower temp thermostat can go a long way to lowering your temps for alot less money.

Gears. I'd definitely consider gears. I haven't done the gears yet on my C4, but they were the first upgrade other than exhaust I ever did on my first Z28 and they were the first upgrade I did on my 96 Firebird. Bang for buck, you can't beat a set of gears, period.

Headers, I know you don't want to do them, but headers make a pretty big difference on all of the C4s and there are several companies that make headers which are fitted well enough to make installation hassles fairly minimal.

New injectors, O2 sensor definitely.

Other than those, I'd get a cam, and a valve job. The mods you have listed for the most part are very expensive when combined together, and would pay for the cam upgrade and valve job and don't really get you anything.

 

I had to learn early on to be careful how you word your response on here as it can easily be taken as an insult or jab. If we were all on video response's it would proabably not happen so easy. In any case I think a 2 row radiator is money well spent. An oil cooler is a possible investment. It was a factory option if not on your car other C4's. Remember you typically get what you pay for when it comes to parts. What I mean is I was gonna buy some cheap oil cooler and my buddy thew me a word of caution suggesting a oil cooler that has a thermostat would be a better chocie. You really need to consider the long tube headers. As I understand it the LT-1's exhaust sytem is good except for those factory exhaust manifolds. If an imporovement is to be made on the LT-1 cars exhaust system go with long tube headers.

 

You guys recommending radiator$$, why? How will that help anything? The OP didn't mention that he had a cooling problem. (?)

That is a lot of money to spend to gain no power and fix no problem.

 

Thank you all for your responses! No better way to figure these things out than to hear from the guys who have already tried them.

My reluctance to install headers centers around two thoughts:

1. I have had headers in the past on C3's and they always required constant maintenance to keep them torqued to the heads. Additionally, I have read many posts regarding heat affecting nearby components on C4's. From that perspective, my headers would have to be either ceramic coated or Jet Hot coated both internally and externally, adding significantly to their cost. Your experience on the above would be appreciated.

2. Having sold my last Corvette (an orange '75 L82 4-spd. convertible) some 32 years ago, I was never a fan of the C4. However, when it finally came time to buy another Vette, after much research on this and other Corvette forums, a C4 offered the most bang for my buck. Additionally, you C4 guys seemed the most fiercely loyal to your model.

At first, I wasn't sure I had made the right choice, thinking maybe a C3 would have been more to my liking. However, as the time has gone by, my C4 has really won me over. There is no denying the sophistication of the C4 over the C3 and I'm also coming to see the C4 as one of the best looking Corvettes in the lineage.

What I am leading up to is, at some point (within a year or two), I expect to move on from the C4 to a C6. The addition of headers under the hood will mark my '96 CE as somebody else's hot rod (even though I don't drive it like that). I am afraid their appearance will devalue the car. All other mods are either upgrades (roller rockers, as an example) or easily reversible (air filter housing, etc.). I was always leery of buying a car with headers - never did - and that's why I'm so hesitant about them now. If there are headers that mimic the stock mounting points, please enlighten me.

To some of you others who have posted suggestions, your points are well taken. My car does have the 3.07 gears and since my wife and I take day trips around Florida, I don't expect to go to 3.45's.

As it stands now, Bosch III's w/ O2 sensors an adjustable FPR, and free-breathing air filter housing are currently topping the list. I am also thinking that investing in a PC lap top (I have MAC's) and tuning software may offer more power than many of the mods I was considering. Your thoughts?

Again, I do appreciate your input, even when I'm being scolded for what are taken as wise-guy remarks!

 

Well you know how it goes with stock cooling and adding ponies
I did clarify and mention that if he's not having overheating issues a cooler T stat will lower temps and save him alot of money on my edit.

That being said, I'd definitely go through the radiator with a fine tooth comb if I was keeping the stocker. The plastic tanks and hose connectors on the sides will be pretty brittle on even the newest C4, and I had a "never happened before" happen to me with my stock radiator. Apparently, the lip on the -end- of the barb that the radiator hose connects to Rotted. (Not the barb or the fitting itself where all the pressure is going to be from the clamp) which was why I replaced mine, that and it would run uncomfortably warm on the 100+ degree days if I'd driven it a while.

That's mostly why I made that particular recommendation.

 

He made mention of being in FL and that it gets hot there so any thoughts on a radiator ? The American Eagle all aluminum radiator is less than $200 off ebay delivered to your front door. The plastic shroud needs to have a dremel cut out space so the radiator cap can be turned. The rubber mounts which hold the radiator and condensor need to be cut to accomodate the bigger radiator. I myself found the 2 row radiator to be the cheapest and best overall modifcation made to my C4. Granted I am a bit bias about temps living in AZ. I do think the long tube headers are a worthy investment.

 

As for the folks recommending aftermarket radiators I just want to say the stock radiator has been good enough for my C4.


I live in the swamp and summers here get pretty warm but at least its a wet heat. I'm still running my stock radiator with NO ISSUES, even in traffic. However, I am running a MEZ HD EWP which helps things stay cool at low rpms. As for longer drives 've never had issues on Multistate roadtrips and I've done 1000mile days.

If I wanted a 350 RWHP c4... I'd have to remove at least one plug wire

Mike