jkr2wld

Hey guys how's it goin? New to the forums and I just got into the racing scene but I have a couple questions I need answered before I go any further into modding my car.

I got a 93 Camaro Z28 (stpck Internals and I don't plan to tear into it, just want all bolt ons and tune the hell out of it). Mods so far are Moroso CAI, Trickflow Elbow, 160 Thermostat, and I've taken off my muffler (Sounds really good actually to me anyway). Which brings me to my questions..

I've been told countless times from old school people "you need backpressure" and then I've read, from new school people "just run cat back or straight pipe" Now my future mods that I wanna do this month, is Order the Summit X pipe and Run true duals w/ new cats with Pacesetter LT's. I read a post last night that if you have no backpressure you can bend your intake valves? Is it true? (I've only been driving with the muffler off for 3 weeks now) will the long tubes make my exhaust that much louder without a muffler? and in order to put in the LT's I will need the EGR block off plates and flanges I think it's called? or extensions? (Not to be confused with the O2 ones, I know about that one) I wanna make sure i buy everything to put the long tubes in.

Any help would be appreciated. thank you

Bowtie Boy

Backpressure is way overrated and more of a myth that wont die at this point then anything. Just removing your muffler on a stock system wont harm anything motor or performance wise. You still have alot of small piping for the exhaust to flow through.

The most popular setup is long tubes with an X pipe but you can do several other options. Open Y pipe, y pipe with muffler, full header back single exhaust, headers off the mufflers. Each has pros and cons its up to you what you want to ultimately do but keep in mind future mods, street use and emissions. Do the research of each setup and determine which is best for you.

idformula

You don't need backpressure, but having the right sized piping is better that too big or too small. With too big of exhaust pipe for a motor, the exhaust gases cool too much and therefore become dense, dense exhaust gases are harder to move than hotter gases.

TheTransporter69

iTrader: (5)

don't need any back pressure. long tubes wit no muffler is really loud, i had it for a while. may be diff with cats, i had cats added to my setup to tame it down. ad for the egr and air stuff, if you get headers that keep it you wont need to block it off. if you get off road headers then you need the egr block off plate.

jkr2wld

Yeah, I'm planning on getting the long tube headers, which require deleting the AIR and EGR. I just wanna make sure on the loudness because I'll buy the high flow cats, just wondered if im gonna get any attention with no muffler. My muffler guy can hook me up with single chamber mufflers. I just need to find the extensions for the x pipe.. or is it called flanges? I can't remember what else I need for the x pipe other then it 2.5 pipes themselves and the blocking plates and... they looked like extensions, I can't remember what it's called

jkr2wld

and also getting the corvette servo installed...anyone have it installed, what should I expect? I just was told it'll have a smoother 1 to 2 shift and not affect 3-4. I thought it would hold the gears longer..

Wicked94Z

iTrader: (26)

hmm......

Speedy

You don't need the corvette servo since you have a 1993 4L60. Just install a Transgo kit and you'll get nice firm shifts. If yours is a 1993 with NO overdrive, just PRND321 then you will have the good 3.23 gears also.

robsquikz28

iTrader: (246)

Wouldnt that be overdrive???

Wicked94Z

iTrader: (26)

hahaha

defaultexistence

iTrader: (11)

Ok, Us 93' f-body guys must do the heated o2 conversion with LT's or it WILL run like absolute garbadge AND you WILL NOT get your tune right . Solomon @ LT1 tuning AND DataMaster confirm this
Heres my write up and "fastbird" is your source for plug and play..AGAIN heed my words of wisdom..BTDT!

http://ltxtech.com/forums/showthread...ith-LT-headers
or
https://ls1tech.com/forums/lt1-lt4-m...t-headers.html

Buy this harness..

http://www.fastbirdperf.com/93-97F-Body/93HeatedO2.htm

and some o2's for 94's and up . You will not regret it!
Michael

brucer

when you remove a stock type muffler and run either true duals or a
single in/single out muffler that flows alot better then the stock single in/dual out you dont lose power or torque..

what does happen is your power band moves up in the rpm range.. you gain horsepower but you lose low rpm torque..

i bought a bone stock 94 camaro, it had stock exhaust on it, i put on a singlein/single out thrush muffler on it, it flowed alot better than stock, but it killed the bottom end.. i put a $150 2500rpm converter in it ,problem almost solved, need about a 3.42 or 3.73 gear now..

Wicked94Z

iTrader: (26)

these are dyno-verified power losses at low rpm?

speed_demon24

iTrader: (6)

I tuned my exhaust with these for optimum back pressure and torque.

Counted Out

iTrader: (6)

Off-topic: But does the Summit X-Pipe work? I've only heard of people using the Jegs X-Pipe and by looking at the pictures, they are a bit different.

lt1-xjs

You already have a Corvette servo, it came in z/28's. Your shift points are controlled by the governor on the drivers side of the trans.

brucer

nope i dont dyno my car everytime i change the oil...

its enough of a difference it could be felt... so that would tell me it was a decent amount..

for instance, first bought the car it had no muffler, straight pipe, not good acceleration, sluggish off the line...

nothing changed but adding a stock single in dual out muffler, i could tell a difference in acceleration, going from no muffler to stock muffler it created better acceleration from a stop, with the stock converter....

i didnt like the sound, so i swapped to a single in/ single out 3inch thrush, back again to no acceleration and sluggish off the line... nothing changed but the muffler...

after i added the thrush muffler i drove it for a week, then added a 2500rpm champ converter (local converter shop)..car is not sluggish anymore and has good acceleration and power.. it needs more gear, probably a 3.42 or 3.73..

Wicked94Z

iTrader: (26)

with scientific terms such as "sluggish" and "not good acceleration" you have me thoroughly convinced. but could you explain WHY a pressurized exhaust system fighting those spent combustion gasses trying to exit the cylinder would HELP torque production? remember pumping losses are indeed losses, and reversion during overlap (low rpm remember?) hurts torque.

Fastbird93

iTrader: (10)

Here's something for you all to chew on in terms of exhaust and size.

Scavenging. It's a component of the exhaust pulses. Essentially what happens is those pulses create a small vacuum at the exhaust runner and beginning part of the manifold/header. As the exhaust valve opens, that vacuum helps by pulling out the spent gasses from the combustion process, scavenging it. Too small a pipe, you choke off that effect and make the motor work to push those gasses out. Too large a pipe, and you slow the velocity down, again taking away that scavenging effect. This is just in the header primaries. The collector on the other hand should be long enough to allow a successful merge without constricting, then you transition to the rest of the exhaust should be roughly the same size, but (I'm going to use LG as an example) the race style collectors that narrow down then open back up help produce torque due to the sudden cross sectional area change.

Don't think of it in terms of backpressure, think of it in terms of correct piping sizes. As noted above, some restriction is better than no restriction.

jkr2wld

how am i supposed to know? I guess i gotta check it lol but i thought it was 98 and up that the servo was stock? then some do and some dont, well which in the hell is it? but if It doesnt then i can order the transgo kit too.