Hey you motorheads!

R

randlemanboater

God
I am contemplating doing something with the exhaust on my RV.

The stock system seems very restrictive, NO motor noise makes it to the tail pipe, just the sound of whooshing air.

It's a 1999 454 Chevy motor.

I'm looking for improvements in power (in the 2000-3000 rpm range) and mileage without breaking the bank. The RV specific exhaust systems are crazy expensive.

Ferm? Skools? Anyone else?

Thanks
 
running both manifolds into a single 4" on those help alot but then they won't slow down on mountains when geared down. we found that out on the 97 Pace we had with the same Chevy and 454. due to no back pressure. it's a dang if ya do dang if ya don't. ours lost brakes on Blk Mnt. yikes.
 
With a long exhaust like on a motorhome, you don't need a big muffler to keep it quiet. I persoanlly would run a single 3" exhaust out the back on something like that, and run a MAGNAFLOW RV style muffler(large round style instead of oval). MAGNAFLOW gives a good bit of sound reduction, but with no backpressure. The 3" pipe will keep some backpressure and improve your bottom end and maintain some milage. Also run a good quality filter in it, but be careful of K&N's. They are known to slime over the mass air flow sensor in a chevy and cause reduced milage and power. Also run AC DELCO platinum plugs ONLY, and make sure the cap and rotor as well as the wires are good. Don't know how many miles she has on her, but if your close to 50 or 60K with that many years on it it wouldn't be a bad idea to do a full tune-up with a fuel filter. And there are also a few tuners out there that will work on that engine if you want to add some extra OOMPH. And also don't expect alot for milage out of it. The 454 is a good engine, but it is like the old OMC 235 in MANY ways. It will run for a long time if you take care of it and run here easy, but she shore do like her gas. Also take good care of that transmission, a 4L80E can get you for a $1K REAL quick if you don't take care of it either.
 
I do not want to loose engine braking.

It has 36k on it now, the guy who had it before me was a mechanic and drag racer, said he changed the oil and trans fluid every fall at the end of his season using synthetics.

I am not looking for any big mpg numbers, just thought if it were breathing easier, it might pick up a little.

The worst I've gotten is 7.25 mpg, the best was 8.6 (comming down Black Mtn improves your mileage fo sho).

Thanks for the advise.
 
Those numbers are not bad for a 454. That is a BIG ole gas guzzlin beast, but it shore is a powerhouse. At 10 years old a set of wires and cap and rotor wouldn't hurt it, and a good exhaust will help ALOT.
 
Skools Out said:
no need to put 3 inch on lol they have 3 inch from the factory on the Chevy.
Click to expand...

Back in the day some still had 2 1/2" on them since that is what GM put on the 454 in the trucks. If he already has 3", I would run a MAGNAFLOW straight through 6" round muffler and see if that helps.
 
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