Just finished the TB on my XJ!

[nolimits]

I was inspired by the threads on the topic, so seeing as I was bored today, I yanked the TB off my XJ and started to get to work.
I kept it a 60mm bore, as I don't have access to the machinery to fab a new plate, and I needed to have it back together to drive for work tomorrow.

I did the same kind of Dremel job as I have done in the past with the 5.9/5.2 TB...takes forever, but the end result has always been great.

I started out on the botom of the TB and started grinding excess material away after marking where the gasket was, as not to go beyond that point. The "pseudo venturi" area directly under the throttle plate was almost completely eliminated, giving substantially more airflow right at tip-in. I blended that into the very bottom of the TB, thus creating a virtually straight line from the plate to the bottom. The bottom of the TB was also enlarged to nearly match the size of the intake manifold...not quite, but close...I didn't want to go quite that radical yet. I always can at a later date, but after careful observation, didn't think it would really make that much of a difference. I'm probably ~1mm shy of matching the manifold, but that's OK.
On the top side of the throttle plate, I didn't do a whole lot...only got rid of the rough edges, and completely polished everything to a mirror finish. Whether that did anything at all is hard to say...It looks bad ass though!

Today, it's too friggin' hot to really tell if my work actually paid off, or if I just wasted 5 hours in my basement, covering myself in aluminum dust. It does seem a little smoother right off the line, and maybe a little more power in the higher revs, but with this temperature and humidity (98-100*F and 70* dewpoints), I can't really feel a huge difference. That, and to drive a black vehicle with the A/C off on a day like this is just stupid.
It does whistle considerably louder now than it did before at about 1/2 to 2/3 throttle. That doesn't really bother me, though...someone driving beside me will hear it and wonder what's going on under my hood. As if the FIPK honk isn't intimidating enough.

Once it cools off a little, I'll take it back up to the track, and see if it made a difference. My goal is to get out of the 16s without cheating (removing weight). A 15.999 would thrill me.

I'll keep y'all posted.

[nolimits]

Update:

After it cooled off, I took it for a longer road test and it really does feel a lot stronger, especially in the higher revs. It hits 3rd gear at ~68 MPH, and just pulls! 4-3 kickdown at freeway speeds really came alive, too!
I may have lost a teeny bit of low end, though.

Wonder what 62mm would be like?

[catnip]

I told ya its a good mod. Im still extrememly happy with mine. The only downside is that my gas mileage has been worse cause I find myself pushing it a lot with the new mod. I'm hoping my foot will calm down and I'll be able to truly judge what sort of mileage increase (if any) I get.

[nolimits]

Heh heh, me too. I burned up 1/4 tank on the way to work this morning, 'cuz I couldn't stay out of the loud pedal.