STREETSLEEPER

iTrader: (6)

Man I ported and polished my throttle body some time ago and I am still fighting my tune. I have done all long term fuel trim data and got my afr back into line, but I have to decrease Base Running Airflow and start to back off on the throttle cracker also. Anybody had any dealing with this? I really havn't had a lot of time to really delve into the tunning. Last month right before track day I quickly got my AFR dialed in and all but havn't had a chance to mess with it. Just wondering if someone out there has had to tune for it and could give me some pointer before I start in with it again. What's happening is my idle is hanging when I clutch. I did lower the BRA quite a bit if I remember correctly. But if my thinking is correct since I removed all that material that the throttle cracker would need to be corrected as well.

rel3rd

iTrader: (43)

Was the car running right before porting the TB?

Reason I ask is that I did the one on my truck and have had absolutely zero tuning issues, although my engine itself is stock internally.

MY old car had a baby cam and it too had zero issues tuning after porting the throttle body.

STREETSLEEPER

iTrader: (6)

No my car is modded all the way from the lid to a good size cam and heads. It ran like a champ before. I expected to have to some adjustment but I have done some pretty radical changes to the Base running airflow. Sometimes to much BRA can cause throttle hanging. But this only hangs over a certain cruise rpm and it doesn't continue to hang at idle like to much BRA. So it leads me to believe it in the throttle cracker. This is an 85mm throttle body and I removed a **** ton of material, even sharpend the edges to remove any harsh transitions. I'll see if I can get a pic up. I really took a lot of metal out. There is a slight bump right before the throttle blade and I completely removed that as well. It is absolutley taken down as far as it can go. I did a stocker for a friends car and his tune was effected to. Seems I am taking a lot more metal out that others. He had a single cone filter instead of the original box and that car sounded like a old spread bore carb moaning. Really sounded ominus. I am gonna do few different file with some throttle cracker changes and I will report back. I thing that will fix it If I just get off my *** and do some tuning. I can do it but I don't care for it as much as I do engine building and modding.

Slowhawk

iTrader: (12)

With the throttle body ported correctly you should have no changes to the idle quality.Only adjustments you might need to do is the idle screw.If it's hanging the idle screw is too far out or the TB was ported into the closed position which is letting more air through.

Rhino79

iTrader: (7)

I have seen where it was ported too much around the blade and the hole in the blade needed to be filled in order to cut down on the closed throttle airflow.

STREETSLEEPER

iTrader: (6)

Idle quality did not change. It's only with clutch in and moving. The idle hangs a little around 1200 rpm's untill I stop. However I did take 3% out of the throttle cracker and it reduced the RPMs to 1000. So I took another 3% out and that should take it back. I am just taking in so much more air that I needed to shut the blade a little more when I clutch the car. Before the car would idle fine, accelerate fine and ran beautifull. It was just when I clutched the car after I had taken the engine past say 2500 rps it would hang a little. Didn't do it at lower rpms than 2500. It's only when I took the motor up over 2500 and held it there for a few seconds that when I clutched in and let the RPMs drop, that it would hang at 1200 and not return to 875. But this last adjustment made a hugh difference so the next one should do it. But thanks for the replys.

STREETSLEEPER

iTrader: (6)

The blade tollerances were not mollested. I made absolute sure that I didn't remove any material form the blade seat. I left the blade in and taped it so I had a little overhang of tape off of the blade onto the seat so I didn't hit atleast a 1/16 of inch anywhere close to the seat.

minytrker

iTrader: (13)

I have seen more people have to get new throttle body's because of bad porting jobs than I have seen good jobs. IMO its not worth all the trouble for 5hp.

Slowhawk

iTrader: (12)

What is the IAC count at hot idle?

STREETSLEEPER

iTrader: (6)

Old post but just relaying my info here. I finally got the problem solved. It was combo of throttle cracker and Follower decay and delay rates. Bigger opening needs less action to get same air.