I had maxbore.com do my TB since he does 62mm and includes the butterfly for $99 shipped.

I installed it tonight. Reset the ECU. Took it for a spin. 15-20min or so.

Results?

Maybe more responsive off the line. I notice nothing else. Worth $99? Not sure.

I don't want to be a sheep and post I am now racing Mustangs or anything.

 

did you bore out the planum intake as well? from what ive read if you do this then you will feel the diff, other than that if you put a 62mm tb on a 58mm planum intake then the hole is still only 58mm at max

 

Planum intake? Educate me. You mean the intake manifold? If so, I read that's 62mm on the 99+ If not, please explain.

 

i would also like to know this. should the intake manifold be bored out aswell? im gearing up to swap in the 99 intake, is it already big enough or does it need to be bored out?

 

I emailed George and asked him. Will post back once I hear from him.

 

After reading/searching it looks like its not included. It's extra. According to another site, its double. But, I will wait until he replies before I say its true. Bummer, I never read any where anyone talk about this.

 

Pretty sure the stock bore on the 99+ intake is only 60mm, it needs to be opened up to match the throttle body.

 

Just measured a pre-'99 'log' manifold and it is 62mm.

 

Here was his reply.

The plenum opening is plenty big judging by the carbon build up ring the TB had on the back. If you compare the size of the TB to the plenum you'll see that they are almost the same.

 

Maybe try pulling out the measuring tape on the intake?

I've never heard of anyone needing to bore the intake manifold too though

 

Too much effort for me. lol

After reading the gain is 3-6hp. Something probably only noticed by dyno. Which makes sense on why I didn't really see any improvement but a snapper take off.

 

it wasnt the power i really noticed either. it was the throttle responce and the smoother acceleration. ive had a bored tb for alittle over 2 years and when i installed it, it drove alot smoother. like the engine could just breathe better. recently i did a whole ignition tune up and the throttle responce went through the roof. quicker smoother idle to 4500 rpms and almost no time delay if im in neutral. even on the trail if i bog down to 900 rpms or so on a medium hill climb and i setup on it alittle more it opens wide up with no problems.

 

I got a 01 xj and a 62 mm tb and i didnt have to bore it out at all

 

mine's in the mail. I'll have it installed monday, hopefully. I'll post my impressions. I've upgraded injectors, homebrew CAI, and 2.5" catback. I'll probably do a banks header, custom downpipe, and magnaflow soon. It's that or a tire carrier bumper. $70 ebay bore, butterfly replaced, as well.

 

Just my .02, But isn't 62mm to big? That is to say: Too much air for a stock motor?

I have taken the taper out of the stock TB and did notice better throttle response and more felt power on the low end.