Next week I plan on getting some ER rockers and NGK TR55 Iriduim plugs. I need to have Ryan @ GM Tuners make a new chip, and I was thinking that I might as well port the throttle body. I am considering having it ceramic or powder coated too. So, im thinking of getting a used TB and opening it up. Any tips for porting the TB?? The Do'* and dont'*... much appreciated

BTW, I installed my Magnaflow cat today. The bonnie has a nice tone to it, even with a Walker Quietflow2 muffler (no resonator). Im hoping to see an improvment in mpg too. Got almost 170K on the original cat. It survived an engine hydrolock and burning coolant and was still working good when I put the magnaflow on.

If you port a TB it will throw off the MAF calibration curve, and only an iterative tune with a tuner can figure out what the new curve will be.

As you are getting a chip burned remotely, I would suggest you get a stock TB with a bigger bore and a known MAF calibration curve. For example, a 99+ L67 TB and MAF sensor.

if you got a MAF and TB from the same year, would it be easy for GMtuners to burn the chip to work fine with that combo? no other hard parts needed?

So long as you get a Series 2 L67 stock unmodified TB and it'* MAF sensor, and you run with the MAF screen in place, the MAF calibration table will be known and can be written no problem.

As you are Series 2, you will need no other hard parts to install an L67 TB; you will have to fill part of the baclk with epoxy and you may have to modify the mounting holes to line up the TB outlet with your UIM inlet, though:
http://www.bonnevilleclub.com/forum/...ic.php?t=77710

(Ignore the hp estimates in that thread; I afterwards learned more about the PCM'* VE table and it'* lack of relation to actual volumetric efficiency ):
http://www.bonnevilleclub.com/forum/...ic.php?t=78557

I've been running this modded L67 TB on my L36 for nearly a year now, and still see no reason to mod the TB outlet to match the "butterfly" shape of the L36 UIM inlet.

Bear in mind also that the greatest benefit I saw on my lightly modded L36 was in initial throttle response, not so much at WOT:
http://www.bonnevilleclub.com/forum/...t=l67+throttle

(Actually, now that I remind myself of that, I think you should get in touch with GMTuners and see if they have access to a MAF-limiting table like I mention in the thread above on a '95 PCM...heck, that table may not even exist on a '95 PCM, I don't know.)

There are similar maf tables in the 95 pcm.

It would probably work and if it doesn't, gmtuners could would be able to get the tune on point.

As for matching the butterfly shape, I see no reason not to smooth it out. It can only help and there is nothing saying it dosen't.

you can save yourself some money by getting the delco iridiums. they are made by ngk. if you look at the delco 41-101s, you will notice the ngk part number stamped in the steel.

Ryan from GM Tuners recommended going with a ported L36 TB rather than a L67 TB because he said the L67 TB doesnt seal properly. I have access to a Snap-on scanner so I can give Ryan the scan tool data and he said it may take a couple of burns but he can tune it. Why a 99+ L67 TB??? Whats different with the 98 and older? Also, Is delco 41-101 the part number for the Iridiums? Am I gonna see any improvment running these over my stock Delcos?

i believe the 41-101s(iridium) to be the oe. maybe 41-140(platinum version of same plug).

have to check, ill get back to you.

edit* http://198.208.187.182/internet/Vehi...e=25&part=7212

Cool. My plugs are only a few month old. But, I planed on pulling them out and checking them when I do the rockers anyway. And since I have them out, I mine as well put some colder Iridiums in.

Don't forget to post the pics of those plugs once you get them out! Several of us are waiting to see if the mod on your runners has had any effect on them.