Now where have I seen that Green Corvette before........:D

UPDATE
Well,

I took the intake track apart to clean the MAF. Got some MAF cleaner.
The MAF was dirty, but I can't tell you how dirty as I've never seen one up close before. So I cleaned it. I assume the critical area is the little devices between the parallel posts. They shine now. I need to research what they actually are being the electronic nerd I am.

The MAF part number is 25168491 and has no screen. From a later LS1 I gather. I found this article that explains the fact that the 2 MAFs have different calibrations.
http://www.ls1howto.com/index.php?article=25
So if my car wasn't tuned for it.......

I just left it in the lid of the Vararam. Speaking of which must be an old one because the filter was a mess. Some sort of foam looking thing that I think would fall apart if washed. I'm not sure how they ever called that a filter. It was clearly letting unfiltered air pass by it. So I'll get a K&N to replace it with and RTV it in place as others have suggested.

The air bridge was hacked on and looked like it could have been letting air leak around the rubber coupler to the TB. I RTV'd it in place as well.

The TB is 78mm and has a home porting job done on it. It was filthy. So I removed it and cleaned it as well.

I noticed an oily residue in the intake manifold. No doubt from the crank case vent system. I can only imagine what the back of the intake valves look like. Caked with gunk I'm sure.

Anyway, I have to wait on the air filter, so the car will be down for a few days. I'll let you know what happens.

Ron

I know it's a little late to say this now and you might already know it but you must be very careful to not touch/bend the little wires in the MAF, they're quite critical.
The dirty MAF and dirty filter (and oil in the intake manifold) may very well be contributors to your below average ET/MPH, hopefully things will improve now. :yesnod:

Hi, don't get the k&n, it won't fit right. Call vararam and have them send you a green filter and lid. It is a little more, but at least it will fit.

I only sprayed, didn't touch a thing.

So I decided to put this back together this AM so I could drive the car.
Whoever put this setup together with the Vararam used smooth tubing for couplers and basically got the main one to the TB too short. In essence, the clamps were barely holding this setup together. So I need to find some 4" ID silicone hose and redo this.
There is a reason that GM uses bellows for couplers. It is adjustable!

As for the Vararam, maybe they work as advertised, but the old version implementation is really sad. I think they should give the updated filter and top for free. I'll make it work with the K&N.

Interesting that a larger MAF was installed, the TB was ported, and smooth tubing was used on a stock engine.

Ron

Its definitely in the MAF and/or tuning. Get it data logged by a tuner asap! The power is wayy down. Most likely because its running way to lean. I wish you were from around here because I could log it for you, I do alot of custom EfiLive tuning around this area. Hopefully you get it figured out soon!

A lot of people use the smooth couplers and on paper they should help smooth out the flow. But they can be a real pain to work with so even though I am all for extracting every ounce of power out of my set ups I still use the stock bellows on both of my cars.






I don't know why that MAF was chosen either but a ported throttle body (when done correctly) and smooth tubing do help (though ever so slightly), even on a stock internals NA motor.
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We did copy the tune into HP tuners.
Is that any help?
Should we compare the MAF table to a stock tune providing we can find that data?
We didn't do any logging though. My buds program and he was tweaking his procharged Z06.

Ron

Update 2

I bought HP tuners.
Downloaded a stock 2000 A4 tune.
Compared it to the tune we copied from my car. (A great HP tuners feature)

My car has not been tuned for the 5 pin MAF.

Yes!

HP tuners is paying for itself already.

So now I have 2 choices. Re-tune for the 5 pin, or install a stock MAF.

LS How To has the table for the 5 pin. Or I'm sure I could find it in a tune for a stock 2003 car.

Fun stuff. I'll let you know how the car runs after.

Ron

Many people run the Halltech and the 85mm 5 wire MAF from the later years on the older cars. It is said that you get better response from moving the MAF up near the TB, your stock MAF would have been on the opposite side of the air bridge. Once tuned appropriately for the new MAF, it should not be slowing you down any more. It's a good swap, but not tuning for it is a bad idea.

Yeah just copy and paste the all the MAF tables from an 03, and you should be golden!

I have a 98. Bone stock other then catback. My best time is 13.52 @106mph with 2.73s and A4. just for refernce too =D

Where are you from? Im down atco all the time(even though my c5 is mostly stock) I want to get it tuned to turn some better times

I will install a stock MAF this evening. Save the larger MAF for when mods are done.
If the MAF fixes the issue, it will be very noticable immediatley in the seat of the pants.
13.5 @ 106 is light years from 14.3 @ 97.

Is there a way to reset the fuel trims or should I just let it idle for a while and then drive it?

I just got the HPT hardware today. I don't know how to use it yet.

If it feels good, back to the track tomorrow eve.

Ron

Yes there is definitely a way to do it through HP Tuners but they will also reset over time from simply driving it and/or a few on/off cycles.

FIXED!

Thanks.

I made the VR power Duct work by putting the correct MAF in the stock location and getting the connection hose I had to work. I'd like VR to send me correct hose, if I can get hold of them. Their email bounces.

Anyway, it's a new car! Agressive where it was lazy. Improved throttle response. It actually stands up and marches on a 3-2 downshift on the freeway! I mean it goes. Shoot, it's almost fast now. :rock:

Drags next weekend weather permitting. It got too late today. And I want to let it learn more while I drive it.

Shoot, I got my HPT kit in the mail, I can even log it and see how it's doing.

I'm happy now!

Ron

Ron post up how it does!!

I broke my Z06 already..... tranny **** the bed..... $3k down the tubes....:ack:

I ALMOST made it 3 wks before breaking it...:crazy:

Congrats on the fix, always nice to see a solution to a problem in threads like this.

Bummer Alan. Hope you get it back together. Maybe upgrade the weak part? Whatever it was?

Ron

Thanks man. Not expecting eart shattering results, just back to what it should run. I'll smear my own egg on my face if it doesn't. :D

Ron