Hello fellow third gen owners....after a 10 year hiatus i am back...i am still active duty military...and i have that itch to get that Camaro running again....I am stationed in NC, Jacksonville (Camp Lejeune) and the car is in Richmond, Virginia....i know the car needs freshening up since its been around 10 years....and of course a new dyno tune. I am currently overseas but would love if i came home to my Camaro running and running good. Who here knows a shop either in VA or NC that can work on and dyno tune our cars? My car is a 1992 camaro with a 385 HSR, LE 2 cam and AFR 195 heads. Any help is appreciated.

 

Welcome back and thank you for serving! I've always been told not to try to run the old gas thru the system. at a minimum drain it out, including near the engine. guess it depends on the fuel situation. old gas risks mucking up fuel injectors and such. watch out for that very carefully and do some homework on it.

 

Oh definitely my friend. I will drain all fluids...thats not what brings me to the board....somebody to work on it and dyno tune it.

 

Welcome back and thank you for your service!

 

Well gents...I'm back stateside but sadly the car isn't running. Jeff Creech at Carolina Auto Masters has the car. It's getting the AFR heads ported along with the Stealth Ram. And since I ordered the S60 rear end....might as well go custom cam. Lloyd Elliot is porting my stuff and has already recommended a cam for me. IIRC he said a 231/239 cam and around .580/.601 lift. It looks similar to the Lunati Voodoo cam which a member has on here and one a 355 M6 guy has on ls1tech. Needless to say I am excited because jumping from a 224/230 cam to this cam will put a smile on my face. A few other changes to the car....

junking the hedmen 1 5/8 longtubes and going with Dyno Don shorties with dual 2.5 inch cut outs.

As mentioned S60 with 373s. 410 mightve been optimal but I might spray later on...

I'll see what the dyno says but possibly going from my 3400 stall to 4000 stall...STR of maybe 2.4? EDGE most likely.

Now....opinions guys....I THINK the dual cut outs will suffice. The guy on LS1tech dyno'ed at 422rwhp around 6200 RPM. I think since I have more cubes and he has the M6, they will cancel each other out in regards to dyno numbers. But I am debating between the Speed Engineering true 3 inch duals for LS1/LT1s and having an exhaust shop make it work OR Hawks 4 inch Sinister exhaust with a Hooker Maxflow muffler (wished there was a 4 inch Aerochamber muffler)

 

Welcome back from you hiatus.

I took a leave of absence for 12+ years, maybe closer to 15... I am back though, and love my 3rd Gen.

 

Are you going for maximum output? The short header is going to leave some performance on the table but beyond that, put as much exhaust into it as is practical. At a minimum, 2 x 2.5" (9.8 sq.in total) with a pair of high CFM capacity mufflers. The 4" is great (12.6 sq.in.) and all that however to get the CFM needed for the greatest output, any single muffler muffler is going to be loud. As in a 4" race bullet or similar straight through design. For CFM, the rule of thumb is 2.2 CFM per HP produced at the crank before the loss of capacity starts to trim output. Plenty will argue though but those are facts. A 500 HP engine needs 1100 CFM.
Now, regarding the cutouts. If you intend to use them to achieve maximum output (and I would think you are) do a quick study and determine where along the length from the primary to collector merge you want to place them. In effect, you are trying to reproduce open header results. A well tuned open header design will have some collector extension fitted to the collector flange. Put them in the wrong spot (for convenience sake perhaps ) and torque/HP will suffer. Ever drive your car with open headers on the way to the muffler shop and wonder why it falls flat until the RPM climbs? That's why. Put them at the correct distance downstream (say 18" as an example) and the output will be enhanced. Check out most any engine on the dyno and the headers are built with that in mind. A program such as PipeMax will guide you.

 

I realize shorties leave some power on the table, but after looking at a few threads of dyno's with similar combos and especially with dyno with Dyno Don's shorties vs longtubes, I give up around 20ish rwhp from 2000 to 5000 give or take. After 5000, Dyno Don's headers come back and the difference is maybe 2 rwhp/rwtq. When I need that power (track) it'll be there. On the street, there is enough power there to put a smile on my face without the long tubes.

https://www.thirdgen.org/forums/exha...long-tube.html

And yes, cutouts would be for the track.

 

You realize that header comparison utilized exhaust termination/resonant boxes. So, that kind of renders the comparison pointless. Facts are that are certain minimum length of primary tube and collector are required for best output.
​​​​​Maybe you can ask your cylinder head porter his opinion. Good induction and top tier heads deserve a top end exhaust. That said, on the street you'll probably have all you can handle realistically. But at the track, that 20 ft/lbs of torque below peak (and most certainly more) will be reflected in your 60' times and ultimately ET.
But to each their own. Best of luck. And welcome back.

 

An interesting comparison.....https://www.thirdgen.org/forums/tpi/...dip-into-2.htm . joeblue83 ran 383 with zz409, 200cc heads with miniram and 700r4 and dyno don headers with a cutout. 3 inch if I recall...he later went to 3.5 inch cutout but cannot remember if that was after the dyno graph he posted or not. He was just a hair under 400 rwhp at 5800 RPMs

In this thread, randy92z had same engine combo miniram included but with slp 1 3/4 and 3 inch fatback and T56 transmission.375rwhp 375 rwtq. He then switched to Hooker 1 3/4 longtubes and 4inch mufflex and magnaflow muffler.
https://www.thirdgen.org/forums/afte...tml#post449632 .
https://www.thirdgen.org/forums/alte...;Unfortunately he did not post a dyno sheet and we cannot compare two graphs. His peak HP and Joe's peak numbers are close, but if you take into consideration a 700R4 with a healthy 3500 stall vs a T56 on the dyno, you'll find both are within 5% loss between the two. I looked everywhere to see if Randy posted an ET to compare the two, unfortunately he did not.
while not a direct apple's to.apples comparison, I see this as a orange to tangerine comparison.