Shemp 5

So yeah, the title pretty much says it all. Im looking to gain more power out of my 93 z28(yeah yeah, we always want more power lol). ive got a magnaflow catback on it at the moment. ill obviously do a cold air intake next chance i get. But im also looking into new headers. what will give me the highest gains? Is it long tubes? are long tubes worth the pain in the *** to put in? someone give me the run down on headers since im almost clueless when it comes to them.

What else could i do to gain some power? as for budget, im not looking to break the bank at the moment. i mean i know i could put in a new cam and all those goodies. buuuut cam's seem a bit too pricey for me right now.

also, what hp numbers might i be looking at currently? and if i do cai/headers?

Mr99SS

kooks long tubes cam then head work ...or sell it an buy an ls1 car

plattted

NEW valve springs and 1.6 RRs will help a whole lot. Very cost effective way to go. big increase in power the original valve springs in a ' 93 was 85 LBs. closed. Lt4 or beehives will help a great deal.

Shemp 5

how much is the cost on all this? and how hard of an install? do i need a mechanic? or is this a do it yourself kinda thing? not exactly looking to break the bank or anything. and im still pretty new to modding cars. thanks man apreciate the input a ton

im not really gonna do a new cam if thats what its related to. cam is a bit out of my budget at the moment

plattted

Use new springs, the 1.6 RRs might be found on this "parts for sale" forum. Perhaps Shoebox might have some helpful tips on his great site. Other than that, A GM service manual or Mitchell's manual will help.

Injuneer

Remove the coolant from the throttle body. Only 6HP, but it's virtually free.

If you aren't looking to break the bank, look at Pacesetter long tubes, rather than the Kooks, which are excellent but very expensive. Ceramic coating on the headers is worth it - keeps them from rusting, keeps under hood temps down, picks up a couple HP through improved scavenging. You will need a Y-pipe. You will also need to decide if you need to pass emissions. If not, the AIR and EGR can be deleted.

Do you have a manual or auto trans? Both will respond well to new rear gears - 3.73 for the auto, 4.10 for the manual. If auto, a high stall (~3,000rpm) converter.

ECM tune for the 93 is a bit of a PITA because it requires a new chip burned.

Shemp 5

remove the coolant from the throttle body? ive honestly never heard of that. is it difficult to do? and are there any downsides to doing so? i have heard of getting the 160 thermostat(i think it was 160) that will give a LITTLE bit more power.

I was actually looking at the pacesetters since the pricing was a lot more reasonable. and y pipe i can do, will that affect my catback, like change anything? or will it be just fine? 93 in illinois, i dont need to do emissions so i guess i will delete the AIR/EGR, how hard of a job is that? ill be honest i hardly have any idea what they are lol.

ive got a manual six speed. what does changing the gears do? isnt that increasing acceleration? lowers top end right? and lowers mpg too? how difficult is that also lol? making sure i can do all of this myself, or with a little help from friends.

i had a link somewhere of headers that i was looking at, ill find that real quick and put it below here.
http://api.viglink.com/api/click?for...38101902466410

David94TA

Here you go--it says 3rd gen, but this how it works.

Throttle Body Coolant Bypass - ThirdGen.org

timnfxr

Here's another way to do it. Needs no other parts.

Throttle Body Bypass 1995-1997

Injuneer

93/94 have a different hose routing. Steam line from the heads goes direct to the radiator.

Shemp 5

why exactly does it allow for a hp gain? just curious honestly

.....nvm.... i actually clicked the link lol

Injuneer

The coolant is there to prevent "throttle body icing" in cold climates..... I think that must mean north of the Arctic Circle, because I've driven my Formula in near 0*F conditions, and no problems.

The hot coolant heats of the throttle body, and some of that heat transfers to the intake manifold via the bolts. That heats up the incoming air, which means less air density = less air mass = less fuel can be burned = less HP.

Here's a dyno test done many years ago:

Modifications #8

He has quite a few dyno tests of popular mods:

WS6.COM LT1 Trans Am

Shemp 5

so sounds relatively simple and doesnt seem to have a downside. so as of now, i will be doing a cold air intake and the tb coolant bypass when im home for fall break. then when im home again for winter break i will do pacesetter long tube headers. do i need an off road y pipe? or just a basic 3 inch y pipe? will the pacesetters in the link i posted earlier work just fine? also is it beneficial to delete the EGR/AIR?

btw what is an ECM tune? just researched the ecm tune a bit. i think ill do that over winter break after i do the new headers

Injuneer

An "off road" Y-pipe is a Y-pipe without a cat. If you don't need emissions, that is all you need. The exhaust will smell worse without the cat.

The link indicates that they are specifically for a 93, and that they are "emissions" headers.

AIR system is used to heat up the cat on cold start. The cat doesn't work until it reaches 600*F. If you don't have a cat, you don't need AIR. You will save about 7# by deleting it. It has no affect on performance, since it only runs for a couple minutes on startup, then shuts off.

EGR can be beneficial. The system runs under engine operating conditions that produce high combustion chamber temperatures. That controls NOx, which forms at high temperatures. The most common condition is lugging the engine at low RPM. In effect, it can prevent engine knock (detonation), so there is a small benefit. Again, has no affect on performance since it doesn't operate at idle, not above 3,500RPM, and not at WOT.

The ECM (engine control module) runs your engine. It determines how much fuel it uses and sets the ignition advance. The stock tune is typically very rich in power enrichment (PE) mode. By leaning out the target A/F ratio in PE mode (roughyl, WOT) you can pick up 10 or more HP on a totally stock engine. A tune is also more beneficial on a 93, because it operates in "speed-density" mode. It has no mass air (MAF) sensor. So the ECM calculates mass air flow based on displacement, RPM, inlet air absolute temp and manifold absolute pressure (MAP). But the equation also requires a volumetric efficiency (VE) value, and it picks that value from a table programmed in the ECM. If you make any changes to the engine breathing - intake of exhaust - the VE tables need to be adjusted. An engine with an MAF sensor is more forgiving to breathing changes, because the MAF sensor directly measures the mass air flow. The ECM has to know this to determine how much fuel to add through the injectors.

Shemp 5

alrighty. so ill just get a regular 3inch y pipe, dont feel like deleting the cat lol.is there any downside to "emission" headers really? or does that just mean they are "cleaner"

probably wont delete the AIR/EGR since that seems a tad complicated(without being able to look under the hood and find them right now.)