Exhaust Opinions Wanted - 85 CJ7, 258, stock exhaust - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Exhaust Opinions Wanted - 85 CJ7, 258, stock exhaust

FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitTHE NEW! VANCO DUAL MODE 15Ē/16″ Big Brake Kit w/BlaFS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 06-20-2011, 05:10 PM   #1
kielfortin
Registered User
1985 CJ7 
 
Join Date: Sep 2010
Location: Gorham
Posts: 24
Exhaust Opinions Wanted - 85 CJ7, 258, stock exhaust

Like the title says, I recently finished building a 1985 CJ7, and it runs pretty damn good in the mud and ruts. Only problem is, its a bit too quiet for me, and also I read that having a "straight" through exhaust will improve performance a bit. I'm sorta looking into putting a glass pack in, because i don't have a lot of cash to blow on it, but i want a more manly sound from it. Any suggestion? Thanks to all who respond...

kielfortin is offline   Reply With Quote
Unread 06-20-2011, 05:25 PM   #2
jeepcjoffroad
Registered User
1986 CJ7 
 
Join Date: Feb 2011
Location: San Antonio, Tx
Posts: 27
For me, I only run offroad and I just dropped the whole exhaust after the manifold and came straight back and out under the frame but if you run on roads it is technically illegal. Saying that it is extremely hard to notice.
jeepcjoffroad is offline   Reply With Quote
Unread 06-20-2011, 05:32 PM   #3
TACAMO
Registered User
1984 CJ7 
 
Join Date: Sep 2009
Location: MWC, Oklahoma
Posts: 65
I just took my glass pack off, Just got to annoying. Went with a Thrush Turbo instead.
__________________
Bryce H
TACAMO is offline   Reply With Quote
Unread 06-20-2011, 07:56 PM   #4
kielfortin
Registered User
1985 CJ7 
 
Join Date: Sep 2010
Location: Gorham
Posts: 24
Thrush

Just listened to a sound clip of the Thrush, that sounds great!!! I might put one of those in... and jeepcjoffroad, im looking for a more "street legal" way to do it, because it is my daily driver, thanks for the input though, it is appreciated
kielfortin is offline   Reply With Quote
Unread 06-20-2011, 08:16 PM   #5
Hurricane4
Senior Member
 
Join Date: Jun 2010
Location: , Ohio
Posts: 885
Good exhaust info here - '85 CJ7 with 258:

http://www.jeepforum.com/forum/f8/co...258-a-1228910/
__________________
The unbelievable we can do immediately . . . the impossible just takes a little longer.
Hurricane4 is offline   Reply With Quote
Unread 06-20-2011, 08:47 PM   #6
kielfortin
Registered User
1985 CJ7 
 
Join Date: Sep 2010
Location: Gorham
Posts: 24
Thrush Welded...

Im looking at the thrush welded muffler, just wondering if its louder than stock. my 258 right now is very quiet, and im looking to add some nice noise to it (some deep growls, not crotch rocket style )...
kielfortin is offline   Reply With Quote
Unread 06-20-2011, 10:15 PM   #7
BagusJeep
Web Wheeler
 
BagusJeep's Avatar
1981 CJ7 
 
Join Date: Jul 2009
Location: Bali, Indonesia
Posts: 4,259
This was debated last week on this forum.

I think the concensus was that a straight through silencer increases the pipe length and leaves it open ended such that you do not get pulse reflected, as you would in a reverse flow muffler. The pulses from junctions, changes in direction etc. are important in scavenging exhaust gases from the cylinders as they induce a negative pressure at the valve and the length of pipes etc. are carefully gauged to maximise that effect.

The timing of this pulse and strength can be changed by the exhaust and header geometry and moving to a straight through pipe removes that pulse. You may have the gases flowing with less restriction in the muffler section but ultimately you may not see any benefit in performance, may even decrease performance.

I don't know if we came to a conclusion on this mod. I think the concensus was that it was a poor value idea and that you needed a lot of specific engineering knowledge to make such changes successfully. As part of a package of modifications you could improve gas flow and hence power with a different exhaust, header, valve, carb and filter.

Personally I removed a straight through muffler the PO installed for something more stock and the unbearable noise subsided, performance picked up and fuel consumption dropped. It was gutless, noisy and a pain before, now it is quite drivable.
BagusJeep is offline   Reply With Quote
Unread 06-21-2011, 06:29 PM   #8
kielfortin
Registered User
1985 CJ7 
 
Join Date: Sep 2010
Location: Gorham
Posts: 24
I'm fairly certain I'm going to be going with one of the thrush mufflers, but I have one question... If anyone has any experience with these, do you think the turbo or the welded would be louder? From what I've read, both of them will pro de the same reduction in back-pressure, so performance is basically the same. The over thing I was buying for was increased noise over stock exhaust (to match my mud tires and 4" lift), so now I'll be picking between the two based on sound. Any help would be appreciated. Thanks...
__________________
"In the Jeeping world, if you're not doing it wrong, you're doing it wrong..."
kielfortin is offline   Reply With Quote
Unread 06-21-2011, 07:09 PM   #9
nshefbuch
Registered User
1982 CJ7 
 
Join Date: May 2009
Location: piqua, OHIO
Posts: 1,865
My friend has the turbo thrush on his amc 304 and it sounds very nice but I'm not sure how loud it will be with a 258. I know of another friend who has 258 injected and he uses headers with true dual exhaust with round 4" magnaflows and his sounds like a small v8.
__________________
82cj7 / soa wrangler springs / amc 360 / t18a granny / d300 twin stick / 37" pitbull rockers radials / h1's / 3/4ton d44 with high steering / 14 bolt ff / clocking ring
nshefbuch is offline   Reply With Quote
Unread 06-21-2011, 07:30 PM   #10
kielfortin
Registered User
1985 CJ7 
 
Join Date: Sep 2010
Location: Gorham
Posts: 24
Prices

Yeah man, id love to put some nice headers in, do a dual exhaust, with some nice magnaflows or flowmasters on there, but i just dont have the cash, im only 16, i have a summer job scooping ice cream, and i owe my parents a couple hundred. im basically just looking for a better performing muffler than the 26 year old stock one i have on it now, and one thats not more than like $60 from what ive read online, and from some friends opinion, flowmaster would be the best for the grumble im looking for, but thrush comes in second, and is much cheaper. i think im going to try out the welded, and while im at it, see what the straight pipe sounds like it. thanks for everyones input though...
kielfortin is offline   Reply With Quote
Unread 06-21-2011, 08:03 PM   #11
nshefbuch
Registered User
1982 CJ7 
 
Join Date: May 2009
Location: piqua, OHIO
Posts: 1,865
Don't be down on yourself. Thrush will be just fine and I think you will be pleased. Just don't expect to notice a difference in power and don't expect the sound to be a monster v8 sound. I'm running flows super 44 and once they are rusted out I'm going with thrush. I enjoy the sound of them but nothing compares to the super 44's when they are passing you. I had my buddy drive mine and fly by me and it sounded so mean.
__________________
82cj7 / soa wrangler springs / amc 360 / t18a granny / d300 twin stick / 37" pitbull rockers radials / h1's / 3/4ton d44 with high steering / 14 bolt ff / clocking ring
nshefbuch is offline   Reply With Quote
Unread 06-21-2011, 08:50 PM   #12
adams1985cj
Registered User
1985 CJ7 
 
Join Date: Apr 2011
Location: Henderson, NV
Posts: 837
I was originally going to do the dual headers with dual exhaust all the way back, but instead still went with the dual header but went into a single exhaust (cost reasons) with a Flowmaster 40 series. It sounds sick I have had several people ask if it’s a V8.
__________________
You donít buy it you build it!!
adams1985cj is offline   Reply With Quote
Unread 06-22-2011, 03:21 AM   #13
kielfortin
Registered User
1985 CJ7 
 
Join Date: Sep 2010
Location: Gorham
Posts: 24
Flow 40's

Yeah i have a friend who used to have a sick TJ going (like 7" lift, 38" boggers, locked diffs, etc., you get the pic), and he had dual headers going back to a single exhaust too, and with flow super 40 on it, sound sick, lotta people asked him what size v8 he had in it, wouldnt believe he had a 6 in it. like i said, i love the sound, but i just dont have the money for it. i think im going to run down to VIP and try on a glasspack, though from the mixed reviews ive gotten on them ill probably return it, im not goin to clamp it on at first, just cut out my 26 year old stock muffler then dry fit it. when i find out i dont like poppin rice in my exhaust, ill probs order the thrush welded or turbo, and shove that in. any sound boost i can get will be awesome, cause im runnin 4" lift, 32" aggressively treaded mud king xt's, but it whispers down the road ( i just think its time give a little more cred in the sound dept.).

and the little money im going to make this summer i think is going to go to get the carb rebuilt, and also some troubleshootin shtuff, cause it used to tend to cut out and sputter sometimes driving. was told to change out pcv valve, and i was missing the ccv in the back of the block, which i put in. havent driven it in a week, cause im also waiting for a new valve cover seal to come in, lucky me that blew right after i changed the valves.

lol, sorry bout the lengthy reply and the thread change, but thanks or all your replies, i really do appreciate it, and if anyone has any suggestions im still open to them...(about the cutting out while driving too )!

Thanks

Last edited by kielfortin; 06-22-2011 at 03:25 AM.. Reason: typos, gotta love em
kielfortin is offline   Reply With Quote
Unread 06-22-2011, 05:01 AM   #14
muzzyman71
Registered User
1980 CJ5 
 
Join Date: Jul 2010
Location: Clinton
Posts: 29
I ran a header and thrush glass packs on my straight six. People accused me of having a V8. Granted they are loud and as trashy as you can get, but sounded good. I now go to the junk yard and get flowmasters to put on my two V8's. Never put one on a six though.
__________________
1980 cj5 360 dana 44 T178
1985 cj7 151 dana 44 T178 spring over
muzzyman71 is offline   Reply With Quote
Unread 06-22-2011, 05:25 AM   #15
chooster5000
Registered User
1981 CJ7 
 
Join Date: Jan 2011
Location: scotland, ct
Posts: 372
ive got a flow master 40 on my 81 with the 258 and i like it alot, its not really loud but you definatlly know its running
http://www.youtube.com/user/chooster5000?feature=mhee
heres a video of some driving around my yard with it, see if u like the tone.
__________________
1981 jeep cj-7 258 with t-176 4 speed and 31x10.5x15 tires,
1979 jeep cj-5 gone but not forgotten
chooster5000 is offline   Reply With Quote
Reply

Tags
cj7 , exhaust , glasspack
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.