What simple modifications can I do to increase the hp on my C4 1995 (LT1)?

 

A few links
www.tpis.com

http://www.madvet.com/shop?category=3.12

http://www.madvet.com/shop?category=3.36

 

Long-tube headers
Hi-flo cats
catback
cut-lid with K&N filter
1.6 rockers
tune (www.pcmforless.com)

That should get you a little over 300rwhp.

Add a heads/cam combo from Lloyd Elliot and you've got one mean LT1

 

if its in the magazines, and says it increases HP, then it doesnt

unless its a catback exhaust

 

Seriously, you can start by doing a complete tune-up. New filters, fresh fluids, new plugs, O2 sensors, etc. That will give you a basis for modifications.
If there is a rule of thumb when it comes to mods, it's this: the cheaper/easier to do, the less benefit it will be. Fact of life.

Larry
code5coupe

 

The bottle is one of the few exceptions to that

 

I suppose you could classify it as the "cheapest" and "easiest" of the genuine power-adders, but even nitrous is not cheap nor is it easy by most people's definition. (It IS effective!) It certainly is not a simple modification, as per the original post. I think you'll agree with that.

It certainly is not in the same cheap/easy/simple class as airfoils, Tornados, K&N, mufflers, cut-back plugs, chips, and other no-gain items.

Larry
code5coupe

 

Vortech makes a (relatively) simple to install supercharger kit that will push you over 400 at the wheels.

 

No cheap HP.....go for torque
The most effective for limit money "GEARS" if it's an auto..oh hell you got D36 .....if it's an auto.......

If you got A4 with 3.07s ......then the cheapest is high stall Torque converter if you going to keep the vette stock or mildly modded...then get a 2800-3000 rpm stall Quality TC!

 

If you want quick, simple and cheap, it's the best $180 you will ever spend. You WILL notice the difference, it will take 15 minutes to install, and you will not regret it.

Obviously it won't give you 50 HP or even 30 -- there are great links on this site (a few examples below) that are an easy search away -- but expect to spend both hours and $$$ to get the big gains.

http://www.wku.edu/~nathan.plemons/h...rformance.html
http://www.c4guru.com/
http://temp.corvetteforum.net/c4/vader86/

 

Charlie, I think that your web site ie great and I've pretty much always agreed with what you've said but ....this case is an exception. The gentleman in question owns a 95 C4 not an early model thus:

Long Tube Headers while it may not increase his HP much will make a very noticable difference in his low-mindrange torq (just like it says in the magazines) particularly if he goes with 1 5/8" primaries ...........and......... with the improved exhaust system on the late model LT1 he will get much more bang for his buck with headers than a catback exhaust IF the choice was simply between the 2 mods. Note: neither of these choices is inexpensive. Though the Headers will probably cost more if you have pay to install either one.

Just my $0.02

Mark 95A4

 

I didnt say anything about headers, and headers arent in the magazines.

The fact is, no matter what model you have, the only thing in those catalogs that actually gives power gains reasonably approaching those advertised is the catback exhaust.

All I was doing was giving him a preemptive NO to whatever suggestion he has regarding what he saw in the magazines.

And he really hasnt given us anything to go on for recommendations either. Need to know what tranny he has, how much power he would like to have in the end, how much money he has to spend right now. If you dont give me anything to go on, I wont recommend.

 

IMHO the only bolt ons that are going to do anything for a LT1 are Long Tube Headers, 1.6 or 1.7 roller rockers, and a retune by www.pcmforless.com . Air foils, bigger throttle bodies, catback exhaust are going to do very little if any to help power.
The things that do seem to make the big difference are heads and cam.

If it is an auto, a higher stall converter and gears will help. If it is a 6sp. gears will help.

 

Why do people keep recommending MADVET? You can spend $5000 there and gain about 25 hp. The solution is air-in and air-out. Get a good cat-back system with LT headers, maybe gears, then sooner or later, you're going to end up spending money on a head/cam package. Take your time and study the threads.

 

I have a 95 LT1 6sp that has run a best of 13.28 @104 on drag radials and a 13.61@103 on street tires (the car has the following mods, none of which made the car feel noticably quicker: K&N filter, 160 thermostat and flowmaster mufflers)

I just installed Exotic Muscle long tube headers, random tech cats. The car feels a little quicker but nothing earth shattering.

I just got my computer back from PCMforless late this afternoon but had to go to a work function so didnt get a chance to install and drive. I will report tommorow on the seat-of-the-pants results.

I hope to run the car on the dragstrip in the next few weeks to measure the improvements (hopefully). I am anticipating maybe a .2-.3 improvement.

I will probably install 1.6 roller rockers this summer. Then its back to messing with my Z.

 

On an Lt1 equipped '95 auto with 3.07s, I first added 1.6 Crane Golds. Took a couple of hours to do. I could do it in less than one hour if I had to do it again. Quite a nice improvement all across the rpm band. Pulled harder and lit the tires up pretty good at the 1-2 shift.

Next added the pcm for less programming. Took all of 15 minutes to do. Could do it in about 2 minutes if I had to do it again. It made the car feel quicker and stronger. Just barely tap the go pedal and you're off. I don't think that it actually made as much HP as the rockers, but I know it made a few. The car may not have had a stock module when we bought it. I could tell that I wasn't the first one to mess with it (paint missing on the screws that secure it.) It might have been a pretty agressive tune to start with. Changing out a bone stock one might yield more HP than my swap did. Also added a 160 degree stat per pcmforless recommendation. Runs a about 175 degrees now.

Then added Magnaflow mufflers. Doubt it made any more hp, but the thing no longer sounds "wimpy" (wife's description of the stock mufflers). Couldn't see paying the big bucks for the corsa system. If $ were no object, I'd have gone for the corsa just for the better sound control. Mine has the dreaded drone from about 1600 to 1900 rpm. The good news is, with the 3.07s, it spends no time cruising at the rpm. It had a good sound on acceleration though.

Still way south of a thousand dollar bill and car runs considerably better, still retains good driveability and fuel manners, and has lost the wimpy sound. May change the rear end ratio to something around a 3.42 to 3.73. Or perhaps change to a looser converter. Both of those would take considerably more time and money. Also have to pay a fuel economy penalty for them. Think I'll just enjoy driving it for a few months first.

 

I asked the same thing on Dec. 28th. Had a pretty good discussion on the subject. The group helped me out a bunch. You can get to the thread by clicking my name on the left. Then go to "posts by old motorhead" and scroll down to the last post on Dec. 28th to get to the start of the thread.

 

Installed the computer today. Unfortunately, there is no seat-of-pants difference in the performance of the car other than it seems to run a little smoother. This is mildly disappointing. Sometimes you cant feel a difference from a mod, but dragstrip times will improve. Guess I'll find out in a few weeks.

Conclusion: The headers, cats, header install, and computer tune cost me over 2K and did not provide much of a seat-of-pants improvement in the car. I am confident, however, that the car will show an improvement at the drag-strip.

If you are going to drag-race the car and you are looking for reductions in you E.T. and a better platform for future mods, i.e., cam and/or heads, then I would recommend the above-listed mods.

However, if you are only looking for seat-of-pants improvements, I wouldnt bother. You'll get used to the very minor improvement in a couple of days and then it will be as if you never did anything. I'd spend the 2K+ on something else.

 

I was shocked at how much harder the car pulled after a full tune-up. After that I put in a LT4 hotcam and had the intake ported. Major difference

 

But the tornado intake and my blow off valve exhaust only cost me $10 each and I gotz mad tight horse powwaahhh dog!





couple of free mods (not sure if you can do these where you live or not due to emissions)..gut the cats and cut air lid open. I have just about every cheap bolt on known to man for the 89, but that won't help you much with your LT1