CrawlerXJ

Well, the 2.5" exhaust (thread already done on it) from manifold to tail pipe is completed, k&n intake, hypertech III, 99+ intake, "703" injectors (new). Verdict?

100% WORTH DOING! Very impressed. She get's up and goes. The sound of the exhaust is more aggressive now.

Any questions, ask away.

wifin

MPG differences?

Hypertech III actually do something? Everyone has said computer chips are useless on the 4.0

CrawlerXJ

Completed today. Will report back on MPG.

Not sure why? Hypertech has dyno'd their programmer. The problem is people think they can feel 18hp. It's everything that adds up. I got it for $100 on CL.

Bbasso

so you did all this work and it's worth the time/ $ to do it?
how are your temps and other readable info responding to the mods?
where has the power improved, lower, mid or upper RPM range?
Time will tell on the MPG, please report back when you have some data.
Interior sound?

thanks.

CrawlerXJ

Not much money, really. I have a list posted some where.

Temps posted below (pic). I have done stuff there too.


I'd say across the board. But, most is low.

Check my other link, I did video inside cab.
https://www.cherokeeforum.com/f58/dy...talled-152232/

Atmos

what did you do about cat, muffler, and header? I have to tear down my engine because I am convinced there is some serious built up gunk in there. so I was gonna throw some upgrades at it. mainly getting an APN header and coat it with polishable ceramic coating to avoid future problems

but I read the 99 intake was a significantly sucky upgrade because it cuts out low end torque and it's actually -2hp or so

Atmos

oh. just read in your other link about muffler and cat

CrawlerXJ

My butt says it feels more than 2hp. I can hear the exhaust tone change too. More throaty. So, something has changed.

http://mallcrawlin.com/forum/showthr...L-DYNO-NUMBERS!
Result on Rear Wheel Horsepower on actual chassis dyno.

HP GAIN: 26.9 Rear wheel HP
TQ GAIN: 19.7 Rear wheel TQ

Atmos

"The Grand Cherokee was run normally in city driving for one month, to make sure that there were no bad effects from this modification. I really did not see much increase in gas mileage that has been reported on the Internet, but there was no decrease either. The engine feels much stronger above 3000 rpm, but I had to know the real effect."

so how much time do you really spend driving above 3000rpms?
here's a quote from JPmagazine

"While a free-flow intake manifold can deliver more power, it's only going to allow as much air to flow as the cylinder head and camshaft will call for. Upping the intake runner volume too much will cause the intake charge to lose velocity, killing low- and mid-speed power and torque. On a '98-earlier engine running a stock camshaft and unported cylinder head, it's wasted effort."

I know I spend a lot more time in mid and low range rpms. especially when crawling. so this would be a pointless "upgrade" in my case
any ways my main question was what did you do about your header?

CrawlerXJ

I live where there are a few 6% grade hills. So, 3k...I do.

Stock. Why? It looked good. No cracks. I do like the OBX though. It has 3.5" at the attachment (forget name...its late)

Atmos

eh. I saw plenty power increase with me regear. money well spent
just trying to get some ideas for what I want to do to my engine. headers crack. I was looking at ceramic coating too to decrease heat. and flex pipe to reduce stress with heat wrap on the exhaust pipe. have you looked into motor mount upgrades to stop power from being lost in vibrations before they make it to your wheels?

CrawlerXJ

I did, but went cheap. Drivers side was shot. I mean shot. Since I live in a condo and have to take my car some where, the guy asked if I wanted it done since he was right there. No extra charge for labor. So, I went to auto parts store and spent the $17 and replaced it. Labor for swap was $150. Seem fair. Took him 4hrs.

Anyway, I think brown dog makes some. I heard they were good.