What are you guys thoughts on running open headers (on the strip) vs. turbo mufflers bolted to the collectors? Do open headers always make more power? Or does a minimal amount of backpressure actually help. The reason I ask is that I had a Nova that was actually faster with the mufflers on. (the old Thrush Mufflers) I'm not particularly fond of all the extra noise, but if it'll run faster I'll take them off. I have a '68' with a 327 built to the specs. of the old 365 h.p. (yes, the "old" technology) What can I say... I'm nostalgic.

Mark

I'd run the open headers if you're racing. Loud but you'll probably squeeze a few extra horses.

the difference for open headers over 'turbo mufflers on my 302 Z was 2/10 sec and 2 mph faster.... and it sounds great!!!!

Thanks for the input! What on earth would have made that Nova more sluggish with open headers? Never have been able to figure that one out!!

Mark

The reason it slowed down with open headers was because you "leaned" the fuel mixture. The carb should be jetted "richer" with open headers for proper performance.

Good point. The extra "outflow" leaning it out never occured to me. I'll have to tune with the mufflers off. The neighbors oughta love it! http://www.camaros.net/forum/biggrin.gif

Mark

I ran 3" with super turbos all year on 427 but yomorrow(weathering permitting) I'm running open exhaust so I'll let you know the results.

Good luck! Let me know how you did.

I've e-mailed Dynomax asking how much quieter my engine would be if I weld one of their Thrush 2.5"x40" and 2.5"x23" glasspacks together end to end versus one 2.5"x40". I want to run a totally straight through full length exhaust but not be sooo loud that I can't think, much less have to put up with the Police.
I will post their reply. pdq67

I got to race but traction was poor so I didn't beat my best with the exhaust on but my 60' times were 1.9 and I still ran cosistant 12.27's all day.My mph went to 111.5 from 110 before.

If the traction was like it was the day I ran 12.14 with 1.67 60'I probably would have gained at least a tenth.

The open headers on your Nova could have leaned out the engine if the jets wern't changed.

Thanks for the report craggar. So even with the poor traction it was still a plus. I'm really itching to get mine to the track, but the season will probably be over by the time I get it back together.

Hey pdq67, whereabouts in Columbia are you? I'm up in the Hallsville area.

Mark

[This message has been edited by mbrekke (edited 10-02-2000).]

mbrekke,

I'm out at El Chaparrell east of town on WW/ East Broadway. Just drive in by the Casey's store and go all the way to the end and if my garage door is open you will see my car. Come on over and get aquainted some time.

Where about's in the Hallsville area are you??? pdq67

I'm west of Hallsville off Hwy. 124 on Tucker School Rd. Out where the deer and the coons play. Had some fluffy little white dog chase some deer through my front yard yesterday while I was working on the car. It was pretty comical. Thanks for the invite. I'll stop in if I'm out in your neck of the woods.

Mark