About a month ago I bought BigMikeGXP's new throttle body off ebay. I emailed New Era Performance and asked if they would port it for me, since I see they offer ported throttle bodies for most ls motors. They replied, and said you bet. So I sent if off to them to port. I just got it back today, they did a great job.

Stock:


Stock 2:


New Era Port Job:




As you can see the stock TB has bumps in it, like steps. The port job eliminated(edit:smoothed) the steps.

I haven't put it on yet, since its 5 degrees out right now, but I'll keep you guys posted on the results. Has anyone taken a drive by wire TB off yet? Just wondering if I should do anything special, like disconnect the battery or anything.

 

I figure I will post this as well, since AREA47 brought up a good point on another site.


I figured the steps were for velocity. The steps are still there(can't see in the pics), but just not as much; smoother I guess I would call it. Will see how the ETC controls the idle, but guys on LS2's have been porting Throttle bodies, so will see what happens I guess. If isn't working I'll just take it off, I don't have too much money invested in it. Like you always say(area47), someone has to be the guinea pig.

 

I took the steps out of my L67 TB when i ported it and it didn't effect idle, can't vouch for the LS4 however.

 

Well, I finally put the Ported TB on today. I've been working on my snowmobile lately, so I haven't had much time for the car.

Install was a breeze, almost easier then flipping the motor mount.

Started up several times(hot and cold), nothing out of the ordinary. Had the exact same idle. Then I took it out for a spin and logged it. I reset the fuel trims and drove around for about 30minutes, and varied my speed. WOT felt a little better, but the throttle response felt a little more sluggish. By the way the log looks, it looks like it's running a little rich right now, so I'm hoping the rich condition was causing the more sluggish throttle. LTFT's were in the -4 to -9 at part throttle. WOT it was running right around 900mv on the narrowband. I'm going to mess with the tune a little later, to see if I can get the LTFT's up a little.

 

interesting, did you port match the manifold?

 

Not yet, but I see why you should. There's quite a lip on the backside of the stock TB, that’s gone now with the ported one. I'm sure if you port matched that, on the manifold, it would help out considerably. I'm going to go load a new tune into now and go log it again.

I found a log from Saturday night, and compared it to my log tonight, and noticed about a 10lb gain in the engine dlvd torque PID. Both logs had almost the exact same IAT's both nights. Only thing different was the TB.

 

if you don't port match, you gain nothing

 

So everyone with a ported LS1 TB port match's their intake manifold? I understand that port matching would help, but to say you gain nothing, I would disagree. It's not like I added a 75mm TB on a car that has a 65mm TB. Tomorrow I'll see If I can't get a picture with the throttle blade open, so we'll see how much I'll have to port match.

Well, I got the LTFT's back up to around zero. The sluggish throttle response went away, and WOT felt a little better too. The car pulls a consistent 380 - 390lb. tq at WOT now, and seems to pull it higher in the RPM band as well.

 

port matching the manifold gives you the benefit of having a bigger tb. if not, you are only getting the stock amount of air flow the stock tb would give you. i learned this along time ago when i started porting stuff

 

Well I took a quick look today with the butterfly open, and the TB on the intake. What a supid design. It looks as if the TB should have been mounted higher on the intake manifold. The TB and intake don't line up. The only place you would need to port match is on the bottom on the manifold. The TB has no obstruction at the top or sides of intake, only on the bottom where the lip was originally on the TB. GM should have moved the TB up so it lines up better on the intake. Area47, you probably already have noticed this if you have had yours off.

 

i haven't ported it yet, im going to when it warms up, or i get off my lazy ***, which ever occurs first. but i do know what you're talking about

 

odd question, do you still have your stock TB

wanna sell it???