How come nobody runs true dual exhaust on a 4.9? I'm planning on doing this by running two mufflers at the tips with no cat. because I live in Minnesota.
It seems easier and should have better performance, and maybe a sound I will like better.
I ran true duels on my 4.9. my set up will only work for a manual trans. . this is a pic of my 4.9 with the HT 4100 RWD manifold from the drivers side. if an automatic is used the tranny wlill be in the way. I also used a HT4100 drivers side but if i had it to do over i would use a eldorodo manifold for a little better exhaust routing on the firewall side.
------------------ 88 coupe 4.9 Izusu 5-speed Rockcrawl chip. True duels.No A/C .KYB GR-2 on all 4 corners Built to run.
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02:24 PM
Cplensdorf Member
Posts: 663 From: Grass Lake , MI Registered: Nov 2000
When I fab'd mine, it was the limited space between the bend and the rear fascia that presents the biggest challenge...trying to find a muffler that will fit neatly there is difficult to find....I never found one....and...
I guess if you look at the performance gains in doing a true-dual, you may just find it more practical to go with a good free-flowing single with dual outlet......here is mine....
When I fab'd mine, it was the limited space between the bend and the rear fascia that presents the biggest challenge...trying to find a muffler that will fit neatly there is difficult to find....I never found one....and...
I guess if you look at the performance gains in doing a true-dual, you may just find it more practical to go with a good free-flowing single with dual outlet......here is mine....
great pictures but do you have a picture of a side view (water pump side) so I can see beter where i comes out of the manifold thanks clint
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06:58 PM
GT Member
Posts: 911 From: Silver Spring, MD USA Registered: May 2003
It seems easier and should have better performance, and maybe a sound I will like better.
I've always read that connecting the banks gives a smoother sound and equalizes the pulses coming out the tailpipe so you don't get wierd resonances at certain RPM's. Combining the banks also supposedly adds a few HP, whether it's with an H-pipe or an X-pipe, or even with a two into one downpipe of sufficient size.
Still, I plan on using true duals on my 4.9 just because I like the sound better.
The other issue that you have is; if you are running an ecm from a caddy which used the crossover pipe then it only reads one O2 sensor. So, you can run your car with O2 data only coming from one bank of cylinders or reprogram the ecm---or use an ecm from an Eldorado which came with true dual exhaust. Or if you are going carbureted then it doesn't matter.
By the way----I am running single exhaust out through dual tips and everyone loves the sound of my car.
------------------ Proud Member of the North Florida Fiero club 4T60E Parks harness/ Rockcrawl chip-- more to come--
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09:16 AM
jeffndebrus Member
Posts: 2772 From: Jacksonville, Fl- usa Registered: Aug 2001
