I would like to start a discussion on PERFORMANCE gains. Now I’m not a mechanic or a Tuner and this is purely MY point of view and I hope that some of the supporting tuners and more knowledgeable members in here that are kind enough to answer all of our questions will set me straight if I’m wrong.

A lot of owners seem to focus on HP gains and typically for the same amount of money spent on Headers and an exhaust system you could swap you rear end gears and see a much larger gain in performance. I would like to see how much of a HP gain it would take to equate to a stock automatic switching to a 3:76 rear end… I think we would all be pretty surprised!

My reason for opening up the intake and exhaust is to make my engine happy. The less it has to work sucking in air and pushing exhaust gases out the happier it’s going to be and the longer it’s going to live! :)

You make a valid point if we're talking about getting down the dragstrip the fastest. It really depends on the owners goals for the car. Some people like to retain stock gears for the sake of mpg while cruising but like to add hp mods to have a little more on tap. Others like to add things like exhaust purely to enhance the sound. If you're talking performance at the strip then yes, gears are a great way to move down the track faster. Weight reduction is another way to get the car down the strip faster without adding hp. There are lots of ways to increase performance without adding hp. HP power is also easy to quantify via a dyno so it allows a car owner to know exactly what they gained for their work and money. That's a little tougher to do at the track unless your car is very consistent because there are so many variables that come into play when racing. I like your concept of comparing non-hp mods to hp mods. There are more setups like this in the f-body and GTO worlds than with vettes. There area a decent number of F-body's in the 11's with only bolt ons. This typically includes intake and exhaust since they're simple mods to add hp but these cars will also have converters or clutches, usually gears, suspension work, and weight reduction. In fact I'm sponsoring a women with an '04 GTO looking to be the first bolt ls1 gto in the 11's. She has headers and a catback but everything else is suspension, weight reduction, and a converter is coming. She's at 12.37 currently.

Performance has three components: acceleration, braking and turning. On a RR track braking is the first and most imp upgrade, then handling then last hp.

For the street, many folks like to increase hp for fun! Great. The problem is that most upgrades can be a waste of money. Spending $2-3k to pick up 30-50hp isn't a wise use of money in my book.

To get useful hp gain you need a head cam set up or FI (TT or SC). The first will run about $6,000(ideal for road racers) the second will run about $9,000(ideal for street),

My 2 cents.

Tom your 2 cents are worth more then mine!

And you're both right of course, I should have clarified this as a discussion for the typical street runner who thinks that bolting on high end exhaust and intake systems are the best performance gains that he or she will get... I don't believe that it is.

And you both hit it right on the head as far as I see it, if you want to get serious you HAVE to look at the car as a system and have a performance goal in mind before you start throwing cash out the door...

For instance new gears and better tires would make the car feel like it just got 90 HP (I have NO idea how much, I was hoping to find out from one you more savy types! :lol: ) in the 1/4 mile...

Excellent posts!!! Thanx for taking the time.
:cheers:

Tom is correct about many things there. Performance is in the eye of the owner in many ways though. If they want to drag race, weight, gearing, tires and HP are king. With RR, Tom nailed it.

Either way, weight reduction can have a profound influence on the performance. Also, a set of gears can really make a car feel 100% faster. Especially on automatics. Customizing the trans shifting to driver needs are another area where performance can be gained. The factory is concerend about 150K mile durability, emissions, and EPA mileage, so it's definitely not optimized for you.

If you need to deal with emissions laws (California) then an EO'd supercharger might be your best bet (besides gears & exhaust systems).

Thanks guys. I think your both correct that identifying goals is the first step. Then you can come up with a good plan.

I'm a RR guy with no 1/4 experience. From what I've heard from the the guys that are the latter; a pair of tires that hook, an after market clutch and a centrif blower should give a lot of bang for the $$$ in 1/4.

For folks that want the hp and think they may try RR or HPDE in the future I would suggest a head cam package instead as SC is tough on RR(heat issues).

:iagree: Or a slightly milder 402/418/427 set up for RR would be a lot more fun than a smaller engine with a lot of cam/compression that just sccccrrrrreeeeaaaammmmsssss at the top but is harder to drive. But then again... :D

Some FI applications can work at the track if you have a front mount intercooler as well as extra oil cooling. We've completed a couple of them and the owners actually do road race them.

:iagree: Or a slightly milder 402/418/427 set up for RR would be a lot more fun than a smaller engine with a lot of cam/compression that just sccccrrrrreeeeaaaammmmsssss at the top but is harder to drive. But then again... :D

Some FI applications can work at the track if you have a front mount intercooler as well as extra oil cooling. We've completed a couple of them and the owners actually do road race them.

Good point. I RR'd weekly with a FI set up last year (D1SC centrif blower with front mount intercoolers, ron davis radiator, separate oil cooler, meth inj, tiger shark front). Although I was able to keep the engine cool after some tinkering around, I wouldn't build a FI set up for the track again. This car was a street car adapted for the track.

My track only car which should be completed this Spring has the type of engine your refer to. 427 Warhawk Block set up for road racing.

Tom, I've got to see that car of yours sometime... To be like totally Californian -- It's Bitchin' :D

Tom, I've got to see that car of yours sometime... To be like totally Californian -- It's Bitchin' :D


Thanks. If your ever in our neck of the woods let me know!

Very informative thread guys. :cheers:

:iagree: with you guys. Performance is measured in respect to THAT individuals goals. Guy A wants a dragster that runs fast ets. Hes going to want drag radials,high gearing,and a high rpm engine. Guy B wants a high speed dual purpose street car. He is going to want an engine with a high amount of torque/ and lower gearing/good aero/ZR tires. Guy C wants a competitive road race car. Hes gonna do extreme weight reduction/High power brakes/moderate gearing/and a linear torque curve for controlability. Its all perspective.