[JackMonkey]

I bought a complete 3" Pypes system with Race Pro mufflers for my 68 Firebird. I also have Doug's headers. I did not buy the X-Pipe with the dumps because of cost. Now I am wondering if it would be worth swapping it out. The car will mainly be street driven with occasional trips to the track. Will uncorking the exhaust net any improvement at the track or will it be wasted $$$ and effort?

406
+0.030 factory block
Edelbrock heads, 295cfm@.600 lift
Comp Cams Hyd Roller
factory crank
CAT rods
Speed Pro forged pistons
TH350
3000 stall conv
12 bolt rear
3.42:1 gears

[rkm1003]

I have not had my car at the track yet, can't help but think it will help, but if you decide to go with electric valves for the dumps, it was one of the best $290 I spent on my car!!! I must have spent $60 in gas this week just driving around going from full exhaust to open headers in about 2 seconds. The video doesn't do real justice to how cool it is and how great it sounds. I got my valves from Dave @ DMH Performance. His website is down right now, you can call him direct @ 513-753-3866. You can do a search in here in PY, very good feedback, there are other options out there, research the threads, you be the judge. Check out the video, lemme know what ya think, Kel

http://youtube.com/watch?v=N91cSXagtVQ

[JT_67Tempest]

Originally Posted by rkm1003

Check out the video, lemme know what ya think, Kel

http://youtube.com/watch?v=N91cSXagtVQ

Wow!!! Those sound awesome!!!! I need to get my ride set up with a set of those e-cutouts!!

Johnny

[b-man]

Originally Posted by JackMonkey

I bought a complete 3" Pypes system with Race Pro mufflers for my 68 Firebird. I also have Doug's headers. I did not buy the X-Pipe with the dumps because of cost. Now I am wondering if it would be worth swapping it out. The car will mainly be street driven with occasional trips to the track. Will uncorking the exhaust net any improvement at the track or will it be wasted $$$ and effort?

406
+0.030 factory block
Edelbrock heads, 295cfm@.600 lift
Comp Cams Hyd Roller
factory crank
CAT rods
Speed Pro forged pistons
TH350
3000 stall conv
12 bolt rear
3.42:1 gears

I doubt you'd see any performance improvement.

Back before you could get 3" and larger exhaust systems, uncorking your exhaust was pretty much essential for faster cars in order to wring out maximum performance.

Now that big pipe sizes and fairly quiet free-flowing muflers are available, that is no longer the case. The 3" and larger systems flow well enough that you don't need to bypass the mufflers anymore in order to get the best track times.

Buy the cutouts if you like hearing the 'sound of power', but I really wouldn't expect much if any performance advantage. I don't like having to mess around laying under the car to uncork it, of course if you spend the $$ for electric cutouts this not an issue.

I run a home-made 3" exhaust on my car. I raced it for about 10 years without ever uncorking the exhaust or removing the air cleaner, running 12-flat 1/4-mile times near sea level with a fairly mild 400HP 455 that runs on 91 unleaded premium.

I like being able to hear the engine over the sound of the exhaust while racing, I think it helps you to stage and drive the car better. Mine is louder than most anyway, I built it with no exhaust crossover and side-exiting splitter tailpipes.

[BILTIT]

For racing i prefer full exhaust (except i cannot here my car because of the other open header cars) but for the street i will be adding e-dumps! Gotta love scaring off all those pesky imports with a flick of the switch.

[JackMonkey]

I guess another question would be if the car is tuned for a full exhaust system, wouldn't opening the cutouts cause it to run differently?

[b-man]

Originally Posted by JackMonkey

I guess another question would be if the car is tuned for a full exhaust system, wouldn't opening the cutouts cause it to run differently?

Could cause a lean condition, but probably not a very big change since the 3" exhaust is pretty free-flowing to begin with.

[ANDYA]

I put exhaust cutouts in the same category as a duel quad set up. More for the cool/wow factor than actual performance increase. However, knowing me I'd probably run cutouts and a duel quad.

[Brandi Kay]

If you like switches and gadgets and loud exhaust sounds at your will, GET UM!!


I am, i have the 3 inch pypes with X cross over