negatively affect smog test?

[noskils32]

I pass the smog test very easily but was wondering if the following mods would negativly affect my results. I am thinking of adding an intake and whole new max flow exhaust system. Because I need to go a little faster but can't afford to regear or do any sort of conversion. Anyone know if it will have any bad effects?

[88WRANGRED]

in a jeep you don't want top speed you want low end torque! you do drive a box on wheels like the rest of us right.

do you have a coffee can muffler?

[southtj]

do you have a coffee can muffler?

Hahahahah

So long as you leave the cat in place you should be fine.

[Bounty__Hunter]

Keep the exhaust mods after the catalytic converter, and make sure all lines running to the airbox are hooked back up to the airtube. I had to coldweld a boss on my airtube to attach a CCV tube to the valve cover.

You should be fine as long as you keep the cat and keep all the engine hoses hooked up correctly.

[Junkpile]

in a jeep you don't want top speed you want low end torque!

Wouldn't that depend on what you intended to do with the Jeep?

......top speed is determined by your final gear ratio, not the amount of power your engine makes. If you have both a 500hp engine and a 150hp engine running at the same rpm, both coupled to a 1:1 final tranny gear, comparable rearend gear ratios and the same size tires, both Jeeps would be going the same speed. You can build the engine any way you want, top speed will be the same assuming the previous engine configuration could reach the same rpms as the new setup in final gear.

My "topend" engine is still supposed to make over 300lbs-ft of torque at 2500 rpms. At the same time, while most factory and "lowend" engines tend to run out of steam at 4500-5000rpm, my setup pulls all the way to 6500.


noskils32-- Just buy parts that are C.A.R.B. certified to be emissions legal, and you'll be good in all 50 states.

[noskils32]

See, the thing is. I miss going 80-85 like I could before my lift and tires. So, in a way, I do want a little more top speed to go along with the low end torque. I do a lot of highway driving and my top speed at the moment is 65 on the speedometer (probably about 70). Anyways, I will be doing a lot of highway next year when I get to college and have to drive home for christmas and stuff and would like to go 75 instead of 70 if that is possible without regearing or a swapping.

[Sully]

Unless you regear that little 4 banger is going to hold you back on those big old 33's.

[TwistedCopper]

Originally Posted by noskils32

See, the thing is. I miss going 80-85 like I could before my lift and tires. So, in a way, I do want a little more top speed to go along with the low end torque. I do a lot of highway driving and my top speed at the moment is 65 on the speedometer (probably about 70). Anyways, I will be doing a lot of highway next year when I get to college and have to drive home for christmas and stuff and would like to go 75 instead of 70 if that is possible without regearing or a swapping.

With 33's, 65 on the speedo is more like 78mph. I have 32's and @ 65 on the speedo I'm doing a hair over 75 mph (GPS baby).

75 mph is plenty fast enough for a boxkite with 33" tires.

[XJNick]

Originally Posted by noskils32

I miss going 80-85

Geez... If I go above 70MPH, either wind-steer or "Jeep's gonna explode" noises or both convince me it's not a safe idea

-Nick

[Tug-n-pull]

If you want to go fast the best advice is to trade for a car! Yea I know that is harsh but true. Jeep even the word sounds slow. Jeep Driver speed just does not factor in to this. Just leave a little early and enjoy the nice slow drafty noisy bumpy ride. 4banger with 33"s I bet 5th gear is only for down hill runs now, right? No amount of exaust and intake will ever make up for the loss of the stock size tires. Brother noskils32 please don't get mad at me but I have been there in my dearly ol departed Jeezabel. You just can not have your cake and eat it too. Best to you in the search for the happy medium though. tug

[noskils32]

I could never get mad at you tug. I know that a Jeep isn't for speed but I just wanted to see if there was anything I could do to get a little speed back in her. Anyways, you think I am really going 78? I'll have to get a friend to follow me at the same speed I'm going and see how fast I'm actually going. Yeah, I usually start getting that "my car is about to blow up" sound at about 75 mph but it doesn't reallly bother me.

Anyways, one more thing tug. I would never EVER trade in my Jeep for any other car. I love her so damn much. And yes, 5th gear is basically a joke. When I shift to 5th I actually drop to about 63 mph on the speedometer and have trouble keeping my speed up. But oh well, it's worth it!!!

[Cherokee_MZ]

hey i have no problem going 90 in my 95 Xj (6 cyli, HO, stock tires)
but im getting K& N filter, and cutting some airtube restrictors out
soo il lbe going fast now...
by the way.. jeeps can beat ricers off the start if they don't have huge ass tires and stock gears

[MOngo1970]

Noskills, Another option might be to hold a second set of stock size wheels and tires for your longer road drives. If you still have the extra old stock wheels...decent used road tires would be cheaper than doing all of the other mods, and you could use 5th gear again.

[hi_c]

I agree... just slow down. There are some things you could do to help a little.
1) switch to an electric fan
2) switch to 33x10.50 instead of the 12.50 wide tires (or go down to 32's)
3) sell your 33's and those shackles and get those 31's back on there. with a 2.5" shackle lift and a desire to do 80mph, you're obviously not taking her off-road too much. That 3" body lift and 31's will look better than those huge shackles stickin' out. Just my opinion.

C

[Junkpile]

Have none of you Cherokee owners ever heard of Jeepspeed? What about the Jeepers that were sand-dragging back before the first CJ-7 rolled off the line. Those Jeep drivers who participate in timed hillclimb competitions sure don't build their engines for the "lowend". A Jeep can be built to do anything you want. Making one fast is not a new or strange thing.

Your four cylinder can be built to the point that it would make the Jeep just plain scary to drive. Sure, it's expensive and not exactly the best route to take......but don't let anyone give you that crap about how a 2.5 can't do this and that. It's just not true.

[TerryMason]

Got my 85 CJ7 tested after a speeding ticket, and with the 33" tires, the speedo says 60mph, and I'm really doing 72mph.