Throttle Body P&P instructions

[jonny985]

I just posted some instructions that I wrote up on my site.

http://www.glue.umd.edu/~kraeuter/video.html

I'd appreciate any feedback especially from John D. or Magnus who have done this mod.

I hope this helps out some folks

[xjarayax]

Thanks! I'll probably be doing that this weekend [img]smile.gif[/img]

[MrCoffee]

any 98+ instructions? those were nice and detailed jonny. Anyone trying to mimmick them 98+ style?

[Magnus]

98+ doesn't need it really.

Ok I looked at the PDF.. very nice presentation and pics look good.. however I don't recomend people P&P their TB's like this. ESPECIALLY cam'd cars or power adder cars..

The MAF sensor is now VERY uncalibrated and the car will start goofy and will idle VERY rich... cold starts will also be HORRIBLE.

What you need to do to have a decent P&P'd tb is completely remove the entire post and open up the hole and insert a 99+ MAF sensor in there so its calibrated right.. basicaly almost converting a old school TB to flow like a new school one.

I did what you did but i had so many problems and the car ran so rich I eventually upgraded to a 99+ MAF sensor. Mike Huff is doing the same.

[DEE97GTP]

I would also question how it runs. I did this to a spare TB a couple of years ago and it didn't run that great because of the what Magnus said.

You will find that the MAF is very picky....

DEE

[jersey]

did upgrading to a 99+ sesor fix your running rich problem also was there a noticeable increase in performance

[jonny985]

Thanks for the feedback.

I experiance MINOR cold start issues as well but its not as bad as some cars. At start up it slightly rough and disappears almost entirly once warm. When I'm idling on the street when warm, I sometimes see a little play in the RPMs but it is hardly noticible. I also have the MAF screen removed.

Like Magnus said, my MAF is very uncalibrated but hasn't affected my drivability, although I have leaned my base out 5% with my MAFT.

I plan on eventually proceeding with the 99+ sensor to steady the readings, but for now, I am happy with the results.

[CamaroRob97]

so you just open the tb all the way and just replace the old maft with a 99 plus one?

[ChillPhatCat]

What about dropping in a 99+ TB assy?

[sped214]

<blockquote>quote:</font><hr>Originally posted by ChillPhatCat:
What about dropping in a 99+ TB assy?<hr></blockquote>
I believe the 99+ are throttle by wire, not cable driven. It would take a lot of work to get that to function on a 98-.

[jonny985]

<blockquote>quote:</font><hr>Originally posted by sped214:

I believe the 99+ are throttle by wire, not cable driven. It would take a lot of work to get that to function on a 98-.<hr></blockquote>

This is true, the 99+ TBs are electronic

Regarding just dropping in the 99+ sensor, you have to be very carful taking out the top half of the post or you will break through the side of the TB. This was discussed in the advanced tech forum a while back.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by jonny985:
I just posted some instructions that I wrote up on my site.

I'd appreciate any feedback especially from John D. or Magnus who have done this mod.<hr></blockquote>

Jonny,

The write-up and the pics look great. This kind of detail makes it a lot easier for someone else to follow. I know it takes some effort to do the write-up too. So thanks for following through with that.

I did the full post removal, and I was the one that broke through when I did the top half. Not when I did the post, but when I tried to make a better transition near the opening of the tb.

I can't comment on the difference between only the bottom half or the entire post, because I did the whole thing. (I started out with just the bottom, but ended up taking it all out before I put it back on the car.)

I had a poor idle (hunting up and down, nearly stalling). It surged at light throttle. Upgrading to the 99 maf sensor helped that a whole lot. The idle stabilized, and the surging almost never happens now, and is barely noticeable when it does.

I played with base settings on the maft, and finally found that zero on the base was best for me. I ran 2% lean on the wot setting, before the porting. Afterwards, I ran 6% rich on wot. Until I upgraded injectors to 24's, then I went with a 6% lean setting. It still runs rich on cold start, but that is probably injectors more than tb.

As far as performance gains, well... I did headers and a 3" exhaust all at the same time as the tb porting, plus I blocked off the coolant passage too, and disabled the egr, so I have no idea what the tb port by itself would have done. Mainly I was preparing for nitrous and a supercharger by porting the tb... I know I definitely had to leave the screen in. All this is on a '98.

Putting the '99 maf sensor in, required drilling out a bigger hole to drop the sensor into. It was $100 plus for the sensor, I got mine from gmpartsdirect.com. A salvage unit would be cheaper. Several cars come with 3.8's that have the same sensor. Also required some work on the topside to get a big enough and flat enough surface for the sensor to drop in all the way since it has a bigger outer base.

[Loochy88]

10hp? Really? very tempting

im confused, is this the sensor youre talkin about adding in:
http://cgi.ebay.com/ebaymotors/ws/eB...category=33557
i thought it wouldnt work

[ January 29, 2003: Message edited by: Loochy88 ]</p>

[jonny985]

10 hp was just my estimation from my experiance with this procedure. It hasn't been dynoed.

That MAF is for a V8, it is inline and you need one that goes directly into the TB