This is topic 3" exhaust.... HELP or HURT????? in forum Tech Talk at Northern California Ford Owners  .


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Posted by hidnn.o.s. (Member # 1219) on :
 
What do you guys think with this scenario?

92lx with a 331. Unported Edelbrock heads/intake, custom cam, s trim pushing 13 pounds of boost, long tubes with off road.

UNTUNED it pulls 521 to the wheels with full 2 1/2" exhaust.

NOTHING else is changed but the FULL exhaust is replaced with all mandrell bent 3" over the axle (w/griggs suspension in the rear)

Now what do you guys think? Increase, loss, or no change?

HOW MUCH do you think it would lose or gain?

(thought the topic may do better in this forum)
 

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Posted by 66 AC COBRA (Member # 904) on :
 
i would say it should help, how much i have no ideal

if this is ur new car
 

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Posted by rokcrln (Member # 2536) on :
 
Sounds sweet can you post some pics of the 3" over the rear axel with the grigs.
 

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Posted by Jeff S (Member # 371) on :
 
I'd guess the change if any will be + or - 5hp.

My car on the dyno gained 2hp from puling the h-pipe and runng 3" open collectors FWIW.
 

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Posted by hidnn.o.s. (Member # 1219) on :
 
Jeff, lol, you got screwed.

I will let forced331 post the gain that he received
 

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Posted by Black94 5.0 (Member # 655) on :
 
I dont think it will be worth that much hp....I especially dont think it would be worth the hassle of putting a 3" exhaust over the axle...Maybe if your car is not lowered..
 

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Posted by forced331 (Member # 1270) on :
 
It dynoed at 521rwhp untuned with 2.5in, and 3inch still untuned 557rwhp.
 

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Posted by hidnn.o.s. (Member # 1219) on :
 

quote:

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Originally posted by Black94 5.0:
I dont think it will be worth that much hp....I especially dont think it would be worth the hassle of putting a 3" exhaust over the axle...Maybe if your car is not lowered..

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LOL, the car IS lowered at that!!!!!!!!!! I think it was sure worth it!!!

I NEVER would have imagined that it would have increased that much just by the exhaust. The car litteraly went from the dyno at 521 to the rack and right back to the dyno and put up 557!!! Both times the car had been sitting for quite a while prior to the dyno pull in order to be cooled down.


 

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Posted by 66 AC COBRA (Member # 904) on :
 
36rwhp gain
 

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Posted by racercosmo (Member # 1864) on :
 
Boost needs to get out of the engine at some point.
 

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Posted by racercosmo (Member # 1864) on :
 
And whose car is this?
 

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Posted by forced331 (Member # 1270) on :
 
Its mine!
 

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Posted by Black94 5.0 (Member # 655) on :
 

quote:

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Originally posted by hidnn.o.s.:

quote:

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Originally posted by Black94 5.0:
I dont think it will be worth that much hp....I especially dont think it would be worth the hassle of putting a 3" exhaust over the axle...Maybe if your car is not lowered..

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LOL, the car IS lowered at that!!!!!!!!!! I think it was sure worth it!!!

I NEVER would have imagined that it would have increased that much just by the exhaust. The car litteraly went from the dyno at 521 to the rack and right back to the dyno and put up 557!!! Both times the car had been sitting for quite a while prior to the dyno pull in order to be cooled down.

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WOW, I guess the 2.5" was really restrictive..I thought the Edelbrock heads would have "bottlenecked" the combo more than the exhasut..I stand corrected...

Did you change the style mufflers?...

What "bump stop" do you have on the axle?...I've seen stock pipes rub on a 1.5" lowered car!!...

Hey, if you got 3" over the axle exhaust in there without interference more power to ya!!!

[ May 01, 2003, 10:20 PM: Message edited by: Black94 5.0 ]
 

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Posted by forced331 (Member # 1270) on :
 
Its stock bump stops, The exhaust was custom fabricated over the axels and there is nothing rubbing and they also had to clear around the griggs torque arm and panhard brace. I don't know how they did it, but Im impressed that it clears everything and got me some more ponies.
 

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Posted by forced331 (Member # 1270) on :
 
I had 3 chamber delta flows, now i think they put
2 chambers or there the series flowmasters, there 5 inches thick and only 10 inches wide.
 

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Posted by WANARNM (Member # 587) on :
 
PICTURES!!PICTURES!!PICTURES!!PICTURES!!PICTURES!!PICTURES!!PICTURES!!PICTURES!!
 

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Posted by forced331 (Member # 1270) on :
 
I dont have any yet, i just picked up my car today. I will try to get some as soon as I can.
 

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Posted by Black94 5.0 (Member # 655) on :
 
By the way, I'm assuming that the exhaust was fabricated using 3", "mandrel bends"?!.....
 

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Posted by forced331 (Member # 1270) on :
 
Of course! All bends were mandrel bends.
 

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Posted by racercosmo (Member # 1864) on :
 
I knew it probably wasn't Don's judging from the last time I saw it.

Where did you have the exhaust done, and where did you dyno it?
 

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Posted by Jeff S (Member # 371) on :
 

quote:

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Originally posted by hidnn.o.s.:
Jeff, lol, you got screwed.

I will let forced331 post the gain that he received

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Or... maybe my exhaust system is good. He must have had some shitty Flowmasters on there or something.
 

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Posted by Jeff S (Member # 371) on :
 

quote:

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Originally posted by forced331:
It dynoed at 521rwhp untuned with 2.5in, and 3inch still untuned 557rwhp.

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What is your timing set at? What octane gas? While on the dyno was there a A/F meter hooked up and if so what was the A/F ratio.
 

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Posted by Blown Mystic (Member # 476) on :
 
you gotta let me know who did the exhaust work, I need to get some pipes bent to clear my TA and PHB. If you coluld PM me the place and about how much it costs. Sick numbers by the way, should be fun once it gets tuned.

[ May 02, 2003, 02:21 AM: Message edited by: Blown Mystic ]
 

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Posted by hidnn.o.s. (Member # 1219) on :
 

quote:

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Originally posted by racercosmo:
I knew it probably wasn't Don's judging from the last time I saw it.

Where did you have the exhaust done, and where did you dyno it?

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I figured that it was pretty clear when I said that I would let forced331 post HIS results.

No info on the exhaust, sorry. It was all custom for Tony's perticular car.
 

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Posted by hidnn.o.s. (Member # 1219) on :
 

quote:

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Originally posted by Jeff S:

quote:

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Originally posted by hidnn.o.s.:
Jeff, lol, you got screwed.

I will let forced331 post the gain that he received

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Or... maybe my exhaust system is good. He must have had some shitty Flowmasters on there or something.

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Jeff, he had an off road x pipe out of the mag for his long tubes and a dyno max cat back with 3 chamber flows. He had the flow cat back on there but when Griggs did the work they told him that he would have to put the dyno max pipes on it to clear the suspension.
 

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Posted by forced331 (Member # 1270) on :
 
Jeff S- I'm still running the fuel system with a 255 high pressure pump no external, 42psi injecters, pump gas with a bottle of octane boost
3922 plugs with out the box 6037 box stock edelbrock heads,
the A/F was up and down from 12.1-11.8,before the 3in exhaust the a/f reading was 12.3:1, the 3in exhaust must of richin it. My intake manafoldis a TFS-R untouched, with 1 5/8 longtube bbk headers and a TFS stage 2 cam, I have no FMU or chip. thats pretty my set up, oh its a 331 with 8.7:1 compression, I have plans for a fuel later on when I replace the heads.
thanks
 

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Posted by forced331 (Member # 1270) on :
 
for got to mention its still the stock fuel system and stock A9L computer.
 

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Posted by forced331 (Member # 1270) on :
 
My timing was set at 8 intial.
 

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Posted by hidnn.o.s. (Member # 1219) on :
 
Your two cars (Jeff and Tony) are very similar. You both have lx's, high HP 331 combinations, and Steeda wings.

Both of you
 

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Posted by Jeff S (Member # 371) on :
 
forced331,

I'm curious what your peak torque was with the R-series intake? Also at what rpm where your peak HP and torque?


 

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Posted by forced331 (Member # 1270) on :
 
My peak tq was 512rwtq @ 5500rpm and rwhp was 558rwhp @ 6100rpm
 

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Posted by forced331 (Member # 1270) on :
 
The guy at the dyno let off @ 6k rpm, horsepower was still climbing acording to the graph. 6 months ago I dynoed it I went up to 6400 and my peak was at 6250 who knows with the 3inch. i will try it again and go to 6500 when I get a better fuel system.
 

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Posted by Blown Mystic (Member # 476) on :
 

 

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Posted by Norgs (Member # 649) on :
 
3" would definately help!
 

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Posted by hidnn.o.s. (Member # 1219) on :
 

quote:

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Originally posted by Blown Mystic:

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quote:

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Originally posted by Blown Mystic:
All i want to know is who can bend some pipes over the rear axle. there is no way that should cost 1400

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Try Sandersons in south city I think. They did some work for me and they have 3" mandrel!
 

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Posted by WANARNM (Member # 587) on :
 
Ther caould be a way.. MAC sells there 3" cat back with tail pipes.. I dont see why no one else can make it for you.. Maybe no skills???
 

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Posted by hidnn.o.s. (Member # 1219) on :
 
Tell Mac that the car is lowered at least 1 1/2 inches and see what they say
 

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Posted by racercosmo (Member # 1864) on :
 
It takes a lot of time to fit up and weld short pieces of bent tubing.
 

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