I've had my '93 6-speed for about 6 months. It runs and looks very good -- I'm thrilled with it. It is a daily driver but I often work from my home so I can do without it for a few days now and then. I don't race or track day the car. Occasionally I drive "enthusiastically."

Next week, it goes into a local independent mechanic (ex-Chevy dealership employee) for the 90K service. First time he's seen this car -- however, I've spoken with several of his satisfied C4 and C5 customers and I'm comfortable he knows what he's doing.

We got talking about minor performance mods. He suggested waiting until he gave the car a thorough exam (makes sense to me) but assuming there's nothing budget-breaking lurking in my engine compartment, we thought about a Corsa cat-back, K&N with cut lid, and a "pcmforless" chip programmed for that set-up. I've read mostly positive comments in this Forum about all these mods, but I could not find a thread where folks discussed the pros and cons of this particular setup.

So here's my questions:

About how much HP gain should I expect out of this setup? Any proven dyno results?

Should I expect any problems with emissions, reliability or gas mileage?

Parts are about $1,300 total and I'm sure there's a few hours labor on his part to do the exhaust (the other two are quite easy but I'd probably have him do them when it's there). Are there more cost-effective engine mods I ought have him do instead?

Or, should I just hang onto my $1,500 and put it away toward my "LT-4/C5 Fund?" Based on my past habits I'll probably keep the Onyx about 2-4 years.

Thanks for your thoughts!

 

corsa is a pretty expensive catback. you won't gain anything except maybe 10-15chp max due to the chip, alvin will make some timing and a little fuel adjustments on the chip (he can better answer this for you).

you probably won't really feel much SOTP with your proposal. i wouldn't spend $1300 for the net result. i'd just keep the $$.

if you want to make a difference, with your LT1 you'll need heads, cam and long tube headers. i consider these basic mods.

 

You'll probably see 10 - 15 hp from the mods. The money is in the Corsas, however they are really nice looking and everyone seems to agree that they do not generate any anoying resonance in the interior of the car as other systems seem to do.

Frankly from a performance standpoint the stock exhaust is really good for up to 400 HP.

I would say that if you're going to sell it in 2 yrs don't do it as you will not get your money back in the sale..

I agree with HR90 in that you will see much more power gained by a cam & LT headers & roller rockers. You will then see even more by having the heads ported to further improve flow into the engine.

Good luck with your mods and be sure to tell us what you end up doing

 

10hp or so, almost entirely from the Corsa. Do not waste your money on a chip at this point, wait for real mods like heads/cam/intake porting.

Not really any small/free mods to do with the LT1, everything costs $$

 

Think carefully about what HotRod and Peabody are saying. Real horsepower that you can feel and that has some benefit will take more money and different mods. If you want the sound difference, there are less expensive ways to go than a Corsa. But if you were going to keep the car longer, then a Corsa might not be such a costly alternative.

As others have said, save the money for the next, more powerful car.

 

I'm convinced you will like a chip even for a stock application or near stock car. WE have done alot to improve part throttle driveablity, performance, and take off neusances like skip shift and such. I mean we have completely different fuel (VE and PE) and spark tables even for a stock car.

I'm so convinced you'll like it that I'll buy it back if you don't.

hows that?

 

onyx, for the price i would do this. you'll be shocked at the great deal it is. and i know what i'm talking about. alvin is no fool, and he will make you a happy man

 

I woudn't discount a good exhaust. If anything, you'll love the way it sounds. But you definitely have to go with a tune.

 

You'll barely be able to measure the difference on a dyno, let alone feel any improvement.
Rule of thumb is: $100 per HP, when you are buying aftermarket power enhancers.
At that rate you are at about 13hp, and I think that is being overly optimistic in the case of those three mods; the Corsa may be worth 6-7hp, the K&N and the chip together about 1hp.

Don't let that stop you from going ahead with it....they make nice additions to the sig.

Bottom line:
What to expect from basic mods????
In this case, a cool looking and sounding exhaust.
Larry
code5coupe

 

If you are going to sell it in two years, don't do squat - leave it stock. Otherwise, the mods you listed are a good starting point for later mods like adding headers, cam, ported heads, etc.

 

As we talked about in the PM....



92 A4 272 HP and 303 FtLbs

Only mods: SLP Claw intake, Corsa Catback , and cat elems.

119k on the clock...




If you want the sound, and the extra kick in the pants (trust me, there is one) go for it!

 

Waste of money! The mods will have no appreciation value.

Bolt ons in my opinion are a waste unless you make engine changes, heads, cam, header, etc. Even then the bolt ons provide minimal hp gains.

Racers are looking for minimal gains here and there, making bolt ons worth the money.

 

93 vett what mod to do ?
I think if you do all the mods that all corvette owners do will give about
Nothing that realy matters.
1.6 RR Comp Cam bee hive springs and exaust cutouts will give all you need .
I have tried everything and those are the only mods that made a little difference.
The chip will help the same as when I reflashed my computer.
Nitrous if you want a big difference in hp.
I am still looking at the C6 if uncle sam doesn't kill me again this next year.
Enjoy your car because others do ,just seeing it on the road ,they even wave to you .

 

If you are already thinking you are going to sell it in a couple of years, do nothing. Others have said it well regarding mods and gains, but I will say this, if you decide you want some real gains, make a plan a decide what gains you want (how much hp.), look/shop around at combinations (cam, heads, porting etc.) that will provide the power you want, save your bucks or spend it, and do it.
Other considerations are if you are having somone else doing it how much they want to do the job, that will probably be the part that hurts.

 

 

If you're selling the car in a couple of years, then I would have to agree with others that say to just leave it alone. You won't get any return on the money you put into it and, in some cases, you may even hurt the resale.

However, if you decide to keep the car (and I don't think anyone would blame you if you did - it sounds like a nice car) and feel like doing mods, then I would advise that you put your money into a good cat-back (like the Corsas you mention) and a set of 1.6 roller rockers (like those on the LT4). These minor mods will give you a nice little boost that you WILL feel.

The K&N and cut lid mod is fine, but you won't feel a thing; do it only if you can get the filter cheap, and can get your stock lid modified for free (I took mine to work and had the machine shop cut it for me) or can find a modified one cheap.

Another cheap mod to consider are cut-back plugs. Again, you won't really feel anything, but they have been shown to give a small amount of power and don't really cost much; don't go out of your way to do this one, do it the next time you change your plugs.

A chip is only helpful if you have major mods like heads and/or a cam. Unless you're looking for a chip that turns your fans on at a lower temperature, don't waste your time with this.

Good luck with what you decide to do.

 

THANK YOU ALL FOR THE GREAT COMMENTS!

Seems the majority opinion is do nothing, or save for cam, roller rockers, heads, LT headers, etc. (in addition to the cat-back which becomes important at that point). I've read a bit about those mods and for a non-wrench like me it looks like a lot more $$$$$ (one member PM'd me and said it could get up to $6K pretty quickly).

So, that ain't happening. But I'm still tempted to play with the bolt ons -- here's why:

I'm changing the air filter anyway (and I already ordered the K&N on line before thinking to ask for advice).

Cat-backs seem to gain about 10HP. Some are actually good bang for buck -- but they drone (and I experienced that once -- not good for a daily driver). The Corsas are pricy but look good and no resonance. And oh by the way, the only dyno data so far was very interesting. 92ZR1WANNABE saw 332HP at the flywheel with the SLP, Corsa, and cat elims (assuming an 18% correction factor). That 32HP kicker ought to be noticeable (he says so!). The Corsa and SLP should be responsible for much of that. Now, Christmas is coming and my wife has suggested the Corsa could be an early present if I want it. Pretty tempting.

Finally the chip. This option generated the most disagreement. But here's the thing. Alvin wants to lay it on the line with a buy-back guarantee. How can I argue with that sort of confidence?

So, on Tuesday my mechanic gives the Onyx C4 a thorough going-over and then I have to make some decisions.

But I'll give you all a hint -- I cleaned her up today and splashed some Z-6 on her. Looks like a 4-year car not a 2-year car.........

I'll keep you posted..............

 

the car sounds like its a beauty....funny how just cleaning them up or taking the car for a lil' cruise changes your opinion on how long to hold onto the car..I've had the same experience with my 90'...the car only has 18,000 miles..I've babied her since new...every time I think of selling the car for a new one, I just get in and go for a drive..my opinion changes radically...these cars are so much fun!!!...in terms of the mods....I would do the work...I have a borla cat back exhaust on my car and a random tech cat...the car sound amazing...I rarely find a car on the road that sounds as throaty and every time I hit the gas pedal, I have a perma grin...corsa makes an excellent system as well (you will be very pleased)...the car will breathe better with the k and n and open lid....the chip should give you a lil' boost at open throtle...not much by the way of horses...think the previous posts are accurate in terms of numbers...but you will notice a difference and the car will drive better...I can't argue with Alvin....he's giving you a total guarantee and we all know his impeccable reputation!...let us know how everything goes....Brian

 

Corvette Kid, who knows his stuff, and I have advised you.

Let us know how things turn out, because we too could be wrong.

 

Well my mechanic did the major 90K service today and found nothing wrong. I took the car out for a nice ride tonight and it runs great (of course it did before the service!) More and more, this is looking like a keeper........

So, let's talk about those bolt-ons.......

As I mentioned, I had already ordered the K&N and cut lid, so we threw them on. No one is going broke on that mod!

And, I could not resist Alvin's display of confidence. (BTW, I saw a recent thread on this where a number of Forum members were raving about pcmforless, including one or two owners of otherwise bone-stock cars.) So, the chip is on order.

I'm deferring the Corsas for a little while. I have them on my Christmas list and even at 10HP or so the "fun" factor will probably carry the day. That means Christmas could come early

I wish I had access to a dyno for some before and after tests. Even if the results turned out to be disappointing on an objective basis I'd love to see documented evidence of just what these mods really deliver -- and then share the results with you all.

Next installment -- the chip!