4.6 help

[Modidy]

Just sold my 94 5.0 vert. Was suppose to buy a fuel efficient civic. Came across a good deal on an 01 GT. What kind of performance increase can I expect with a catted x-pipe and cat-back? Any other mods I should consider to keep it mild and somewhat decent fuel economy? I like the idea of 25mpg highway, which most of my driving is.

Thanks,
Mo

 

[MadStang]

Best thing you can do is cai, tb, plenum, and exhaust. It'll boost mileage by reducing the need to put your foot into it more and depending on driving you should change gears. Highway car I'd go 3.55's or 3.73's. City car definitely 4.10's. Modulars are gas guzzlers in the city because the torque is up high in the rpm band and throttle modulation on any v8 will kill mileage. I get about 12 mpg in city with my cammed modular with 3.27 gears and 20mpg on the freeway...

 

[Willis_98GT]

You may want to leave the gear untouched man. a 3.27 gear threw a t-45 puts your 70mph pretty close to 2000rpm right? if i remember correctly.

Best thing you can do is cai, tb, plenum, and exhaust. It'll boost mileage by reducing the need to put your foot into it more and depending on driving you should change gears. Highway car I'd go 3.55's or 3.73's. City car definitely 4.10's. Modulars are gas guzzlers in the city because the torque is up high in the rpm band and throttle modulation on any v8 will kill mileage. I get about 12 mpg in city with my cammed modular with 3.27 gears and 20mpg on the freeway...

+1

with my car the best highway mileage i got was 24.7ish on a highway trip i took with a 3.90 rear and a full bolt on off road prochamber 4.6 pi swapped car with comp 270s screaming @ 2700rpm @ 70

 

[infamous209]

My 96 with a t45 and 3.27 gears does 70 at right around 2000 rpms. I get 22 if I go all freeway, and around 18 for both. Getting 25 mpg in a mustang is doin really good, but could be possible.

 

[GrnGt]

I wouldnt mess with the gears, especially if you are doing highway driving. I have an auto with 4.10's doing 60 at 2500, and I do interstate driving screaming at 3000rpm lets just say the needle drops pretty fast

 

[vermilion]

leaving it alone and driving is the most efficient.

 

[Modidy]

I put a Magnapack cat back system on it, and love the sound. Will be doing a high flow catted x-pipe soon also. Probably going with a CAI to help breath and maybe a plenum and TB. That will be the extent of my mods with it performance wise. As for gearing, with stock gearing, I'm already at 2000 rpm at 70mph.

 

[Bullitt5339]

I wouldnt mess with the gears, especially if you are doing highway driving. I have an auto with 4.10's doing 60 at 2500, and I do interstate driving screaming at 3000rpm lets just say the needle drops pretty fast

If you're doing 60 with 4.10's at 2500rpms, then something's wrong with your overdrive, or your converter isn't locking. I have 4.30's and run 2500rpms at 70mph and get about 22mpg on the highway.

 

[bigkeeko]

I wouldnt mess with the gears, especially if you are doing highway driving. I have an auto with 4.10's doing 60 at 2500, and I do interstate driving screaming at 3000rpm lets just say the needle drops pretty fast

If you're doing 60 with 4.10's at 2500rpms, then something's wrong with your overdrive, or your converter isn't locking. I have 4.30's and run 2500rpms at 70mph and get about 22mpg on the highway.

+1.
Just had 4.10s installed and I`m 2000rpm @60mph. Give or take a ballhair. It was 2000rpm @70 with 3.27s

 

[Jrgunn5150]

Ummm.... Go buy that Civic maybe if you want mileage?

And I know I've been gone awhile, so I guess I'll have to reiterate... The engine side bolt ons do next to nothing for you. A cat back does next to nothing for you... a mid pipe worls wonders.

Save the rest of your money for gas lmao, and a blower.

 

[vermilion]

and a tornado fuel saver.

 

[Bullitt5339]

Engine Side bolt-ons do nothing huh?

Tell that to my 12.5 timeslips on a bolt-on car naturally aspirated.

 

[vermilion]

im betting that bullitt suspension had nothing to do with it?

 

[Bullitt5339]

Suspension is still a bolt-on............ lol

To be honest, I don't even have full bolt-ons. It's still got the stock throttle body on it.

 

[Jrgunn5150]

Engine Side bolt-ons do nothing huh?

Tell that to my 12.5 timeslips on a bolt-on car naturally aspirated.

I'm sure that's all due to your pulleys and CAI Chief, without those you'd still be in th 14's for sure yo!

 

[c_me_pass_u]

I wouldnt mess with the gears, especially if you are doing highway driving. I have an auto with 4.10's doing 60 at 2500, and I do interstate driving screaming at 3000rpm lets just say the needle drops pretty fast

If you're doing 60 with 4.10's at 2500rpms, then something's wrong with your overdrive, or your converter isn't locking. I have 4.30's and run 2500rpms at 70mph and get about 22mpg on the highway.

+1.
Just had 4.10s installed and I`m 2000rpm @60mph. Give or take a ballhair. It was 2000rpm @70 with 3.27s

It also depends on the wheel and tire size because I was running at 60-65 at 2500 on a auto I had 17' cobras r with a small wall tire....and now I have some weld racing aluna stars 15x8 with some mt's I believe makes it to 26 inches diameter and I run better at 60-65

 

[vermilion]

thats a weight difference and wheel ratio difference..

 

[infamous209]

CAI, TB, and Plenum will help with mileage, maybe a tuner also, I have seen numbers that prove this.

 

[Bullitt5339]

thats a weight difference and wheel ratio difference..

My car at full weight with 4.10's was at 2000rpm at 60mph.

 

[vermilion]

about 23-2400 at 70.