mitch123

A Stock 1978 with 185 HP: Without going into the engine, can you increase that HorsePower by doing any/all of the following? If so, how much??

1. Change spark plugs to Racing Plugs and Best Plug Wires

2. Install Headers

3. Eliminate the Catalytic Converter

4. Install True Duals with a top-of-the-line Muffler System

5. Replace the Stock Breather with an Aftermarket One

6. Replace Stock Tires to a particular size

7. Higher quality Oil

8. Higher Octane Gas

9. Replace Stock Carb

10. Anything Else

Would any of the above help with Torque?

randommj

with free flowing exaust/intake you will with out a doubt notice a diffrence in HP, torque? it all depends in where you usually run your RPM's with free flowing exaust you get a lot more torque at higher RPM's than you did with stock exaust set-up

but with the stock set-up you hade more back pressure which gave you more torque at lower RPM, this is why in some cars youll see butterflu vlaves in the tailpipes, to increace/decrease back preassure in sync with the engins load

tires, oil sparkplugs ect wond do a thing for HP but you should change the oil, plugs, wired, and tires if needed anyway

Miles

panic

Putting your vette on a diet would be a good idea, that'll give you a better power to weight relation which means better performance, safer braking and going smoother on twisties.

HamadUP

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Mike Ward

HamadUP has it right. No free lunch.

I'm curious as to why some people think that an aftermarket breather would create more power. The stock breather doesn't use any so what would be the gain?

Clue

What about timing adjustment? Should be advanced way more than factory specs ? I've been told this will easily give you 5-10% more HP.

Billysvette

Maybe a small shot of nitrous will give you 50 ,75 hp more.cant do too much because of your pistons wont handle it.

Aruba1

What about a supercharger?

Billysvette

Pistons cant handle it

PeteZO6

This is a good point! If you remove the cat. and other smog stuff, you will probably pick up a bit of power by recurving your distributor, including possibly a different vacuum can. BarryK has an excellent timing article in the sticky section above this thread.

Cheers,
Pete

Taijutsu

I don't know the flow rate of the stk heads, but they would benifit
w/1.6 RRs. I had TFS heads when I added 1.6s. The engine ran smoother, much cooler and the sweet spot went up 200 rpms.
Well worth the $. JMHO

Ricisan

stock76

Make sure to set up your timing when you do all of the above. Read up on it on some of the articles on this forum. If you are on a tight budget pass on the headers for now. They will add a little HP but a true dual exhaust, a good tune up, proper timing set up, and carburetor adjustment will give you your biggest bang for the buck without going into the engine. The stock Corvette exhaust manifolds are actually pretty efficient though not as "cool" as headers. All depends on how much you want to spend.

BarryK

recurving the distributor to bring the advance in sooner will help with a bit more "seat-of-the-pants" power and well worth doing, and considering the only expense is the cost of a couple of springs from a distributor recurve kit it's cheap to do, but it's sure isn't going to increase power anywhere near 10% as mentioned. But if the distributor is still untouched from stock set-up you should feel a bit of difference.

The stock exhaust manifolds are fairly restrictive so adding a good set of headers, eliminating the Cat, and running true dual exhaust should gain you some more power you can feel also.

Everything else on your list is a complete waste of time and money and isn't going to gain you ANYTHING, especially "racing plugs"!! Give me a break! Run the correct plugs with the correct heat range for your motor and for street driving and stop reading the marketing BS in the parts catalogs. Race car parts are for race cars, NOT street cars. do yourself a favor and take your JEGS and Summit Racing catalogs, look them over very carefully for entertainment purposes only, than throw the d*mn things in the trash.

Mike Ward

but you forgot to mention not to believe everything that's advertised on Speedvision

Hey look, that's twice we've agreed in one week. McFast is going to get jealous.

rebc3

dont be so foolish as to throw those catalogs away, but do be careful of silly things like tornados for the intake and gas line magnets ect, ect

i do believe that an aftermarket "breather" or do you mean air filter, WILL increase power to a degree, hasnt anyone here heard of K&N?
also, tire size will do nothing to increase hp. but will have an affect on your overall gear ratio but it will not be enough to justify the cash output for tires.
tune that baby up real well and replace the springs and weights in the dist. and set the timing more advanced. you may even want to change the dist. all together. old and stock parts dont put out much energy.
all these little things wont do much by themselves but together they will make a difference. the exhaust is where youll get the most bang for the buck without going in the engine.

BTAL

Electric fan for a tiny gain.

Attfay Elleybay

How much HP with an L82 with headers, duel exhaust, no cats? 250?
I've had people ask me and I'm not sure.

BarryK

Yes, K&N air filters may actually add 1 or 2 HP total (big deal) but personally you couldn't pay me enough money to use one on any car I actually care about.

It all comes down to simply physics:

K&N advertises more power by allowing more air thru the filter therefore into the motor. simple concept and it works! If that is ALL you care about than go ahead and use a K&N filter.
What K&N fails to put into their lovely marketing brochures and advertising is that the only way to get more air through the filter is to use a filtering material that also allows more dirt particles through.
so, while you may pick up a slight increase of power you are alos getting more dirt inside your expensive motor. If that is a trade-off you are willing to do than by all means use their filters. i'm not willing to subject my motor to that abuse.

There is a forum member in the C1/C2 section who spent decades as an engineer for GM (in the corvette division no less). After he retired from GM he was recruited and hired by Chrysler and he was the Viper plant manager. during his time as the Viper plant manger Chrysler ran OEM tests on air filters because they were looking for the best performing air filter to use on the Viper. Obviously, on that vehicle power output from the engine was key. during the tests it was shown and proven that while the K&N filter allowed some of the largest power output between all the filters it also showed and proved that it allowed more dirt particles through than any other filter tested. Since Chrysler wanted a reliable vehicle and especially since they would be responsible for warranty service on the new vehicles they refused to use the K&N as an OEM filter on the Vipers.

Gaining possibly 1 or 2 HP simply isn't worth the downside of using inferior filtering capability to achieve the result.

toddalin

You can block off the heat riser on the intake manifold for a cooler intake charge without going into the engine (other than removing the manifold).

Mike Ward

Believing that these filters will give you more power is a good reason to throw the catalogues away.