Pirate 4x4 banner

1 - 4 of 4 Posts

·
Registered
Joined
·
398 Posts
Discussion Starter #1
I need a new exhaust and I'm thinking of increasing the 2.5" pipe to a 3" pipe for a chev V6 in a Toyota. I don't run a catalytic converter. What is the relationship between exhaust pipe size, engine performance / hp and emissions?

I've heard that putting too big of an exhaust = less back pressure but not sure how that works into the power question. I've also heard that putting too big of an exhaust means exhaust flows slower which means less engine scavenging. If thats the case why do people bother putting larger pipes on their vehicles and how do you know if you've gone to big if you don't have an engine dyno at home??
 

·
Registered
Joined
·
4,532 Posts
well, I went out to several exhaust shops around town this weekend getting quotes on exhausts for my buggy...they all reccomended anywhere from 2"-2.5"...one old timer said he put 3" on his 4.3L just to see and he said he noticed a big loss of power, 3" is just too large for a 4.3L
 

·
Rolling Mod
04 Wrangler Unlimited, 67 F100
Joined
·
41,752 Posts
2.5" is more than enough for a v6 in a buggy. 3" would be more inline with a 350 hp v8 with single exhaust. You don't need that much.

I have a single 3" on my 304 in my CJ7. It puts out 200 at the rear tires. The exhaust is waaayyyy too big according to the guys who dyno'd it. I lost most of my lowend and all I gained is noise.
 
1 - 4 of 4 Posts
Top