dmaderaitt

Running Pacesetter racing long tubes 70-2239 and their Y-pipe 82-1161, dumping in front of axle, was wondering how its affecting my power output by running it like this, do I need to run it out the back to get more back pressure into the system or leave it for best results?

Zfbod94

Im sure everyone else is wondering the same thing. What are you using the car for?? DD, weekend warrior, straight race? Is everything in your sig up to date? What mufflers are you running, cats? Need more info to help.


Are you having any problems currently that make you think you need more back pressure?

Skedaddle

In general, there is no need for backpressure. Pretty much a myth, a holdover from the days of carburators. If back pressure was required, no one would be running open headers or a cutout for max performance at the track.

Since you are dumping it in front of the axle, why do you bother to run a Y-pipe? Why not run a pipe straight back from each collector. Put whatever muffler you need on each side to control the noise. The Borla XR1 shorty mufflers are great for that purpose.

dmaderaitt

Its a Daily Driver and something to play around with on the weekends, its still primarily stock(for now) other than the cold air, the cc306 cam with lifters and new heads that got a small port job and slightly bigger valves since car overheated on previous owner, plus the exhaust which I ordered when I bought her back in February to replace some 10 year old shorties that where junk, still has factory fuel system, tune, rear(3.23s) and transmission(Stock), EGR and AIR delete, that's why I'm running the race headers and Y-pipe with no CAT, was going to run her all the way out the back and then dual it after the axle but keep it strait piped, trying to keep it looking stock and to keep max ground clearance, nothing weird happening just making sure that I'm not robbing myself of power and torque, trying to get a tune to take advantage of the cam and line the transmission to it since its an auto, planning on some 3.73s for the rear as well but dry on funds till summer.

Zfbod94

Will def need to tune it. At least

Are there mufflers on it, or just pipes? 3"? I dont see it as a prob.

Sorry for all the Q's, just trying to see whats going on with everything. Does it run strong? No surge or anything from the cam? What kind of new heads, factory or aftermarket?

dmaderaitt

1.75 main tubes to 3" collectors and then 3" Y-pipe dumped no mufflers, stock heads and then had the work done at a local machine engine shop, cam with the auto surges a bit, nothing out the ordinary, has tones of power and will break the rear end loose easily, very fast, but just doesn't seem to have that slam you In the seat type of acceleration, I am thinking of finishing my exhaust and then 3.73s in the rear, just wanting to get it tuned once for everything, not going to be a full drag car just a play toy, everyone says it fast but maybe its slow to me since I've been spoiled in a 420rwhp LS2 GTO for two years now(A buddy of mine that lets me drive it all the time!)

Zfbod94

Damn I wish I could get away with that in my state! haha. Hows the reverb with that setup. I had a fox mustang in the past with dumps right in front of the axle and it nearly vibrated head right off my neck.

A tune will give you what you feel is lacking with the acceleration factor. I would def think about some 30# injectors as well, as the stockers are prolly running high in the duty cycle. You could send it off for a mail order tune, should be pretty straight forward with your mods. Are you running the stock converter. If so I would think about stepping that up before you do the rear, something as simple as a 2500 stall and you will notice a big change from that.

I just got a new 2500 yesterday to replace my old busted 2500. I swapped back in a stocker bout a month ago just so my tranny doesnt get hurt and I forgot what it was like to drive on the stocker. IMO big difference.

dmaderaitt

No vibrations at all except from the arm rest and the gear selector cover since the latch and the hooks are broke off(junk yard trip) but outrageously loud(ear plugs) I just need to be careful when inside city limits for noise restrictions but its NC and most people and cops don't mine since its not a ricer with a fart can, I thought the factory injectors were 26# or 28# already would stepping it up that much really be beneficial, I'm not running forced induction and not planning to, will do that for sure if I drop a 383 in it, still has the stock converter, just didn't have the extra money to upgrade, want to have the one I pulled rebuilt and then get a converter put back in was thinking of a 2400-2600 stall, been looking at performabuilt or mad dog level 2, also PCM for less has a shop in Concord NC(2hrs from me) and was going to take it there for a dyno tune, just waiting for playing money(work bonus)

Zfbod94

The factory injectors are a 24# so some 30#ers would be worth it.

My old converter was somewhere in that range and I felt worked perfect for me. I just got a new protorque 2500 from Frank at CPT, which ill be putting in today.


It def sounds like you have a good plan for the car. Let us know how it turns out.

dmaderaitt

Ok, thanks for the info, found these real quick and the description states no computer and engine mods needed, will look into it and see, thanks again for the help

http://www.summitracing.com/parts/ac...t/model/camaro

Looked at the warning and then it said to match the ecu to the injectors, they need to get that fixed, thanks again.

Skedaddle

The stock injectros will handle 360HP at the flywheel without causing duty cycle problems. If you are over that, you need larger injectors. And when you change injectors to a larger size, you have to have the new injector flow rate and offsets programmed into the PCM or it wil run rich.

Personally, I would not recommend the Accel injectors. Look at the Racetronix website.

dmaderaitt

I found these off that website, will look into them if they will fit right in.

Racetronix - 621020 - 32 lb/hr Disc High-Z Fuel Injector

Zfbod94

The 30# or those 32# will work for you. But as Skedaddle said, you will have to reprogram the computer to use the injectors. You said there is a PCMforless in your area. They can def help you with that.

dmaderaitt

Will do, thanks for everything, will update or post new thread when I get her tuned.

Zfbod94

No problem.

Def post up some pics. Would love to see it