Major flat spot in mid range... Help needed!

[J-1]

Problem solved... Vacuum pipe

[Edophus]

Have you got the stock intake setup? i've tried all sorts of setups now and nothing comes close to the stock airbox with all the snorkels removed, anything else just leans the crap out of it.

[RST]

Sounds strange Jay, my AFR is pretty reasonable with the SARD kit fitted. Did lean it out -but nothing like that. Did you do the run with the rubber bung in the front -or a completely open gauze? What was the comparison against your stock set-up -mine was stupidly rich originally.

[J-1]

Originally Posted by Edophus

Have you got the stock intake setup? i've tried all sorts of setups now and nothing comes close to the stock airbox with all the snorkels removed, anything else just leans the crap out of it.

What do you mean snorkels? Can you show me a picture of your setup?

Im thinking about taking it back to standard.

[J-1]

Originally Posted by RST

Sounds strange Jay, my AFR is pretty reasonable with the SARD kit fitted. Did lean it out -but nothing like that. Did you do the run with the rubber bung in the front -or a completely open gauze? What was the comparison against your stock set-up -mine was stupidly rich originally.

Hi Richard. In the front of the SARD?

Not got anything to compare it to because i never dyno'd it when it was standard.

[J-1]

Heres the graphs.

[RST]

Yea, I mean the rubber cap which sits in the mddle of the filter at the front -covers the little meshed grill. Just wondering.

...BTW, I was never convinced that a set-up with sports exhaust, de-cat and induction kit didn't need some fettling on the ECU side of things to make it all tie-in properly, it seems like almost there on the stock ECU -but not quite.

[Roman]

Well put it this way, you've got the same symptoms as everyone else who had a pod filter setup, who didnt have those symptoms anymore after going back to the stock airbox.

There's no way that your car is running lean on account of running out of fuel pressure, or your injectors being too small.
If that were the case then you'd get leaner as your RPMs increased, instead of a mid range dip. Standard fueling is definitely more than adequate for a mildly modded engine.

My reccomendation is to dyno it again with the stock airbox, and see if that makes a difference. This is what I did, and I gained power EVERYWHERE over an apexi pod filter setup.
And that was going back to a $5 panel filter.

The great thing about the airflow meter setup, is that the engine CAN account for differences in volumetric efficiency... So it wont need a retune after things like adding an exhaust etc.
The downside though, is that it's stupidly fussy about changes to the intake tract, and it seems hit or miss whether or not it makes your engine lean right out or not. If there's one thing that you DONT want to fiddle with (when running standard ECU at least) It's the standard airbox/intake setup. In my opinion.

[RST]

I agree with Roman in as much as it's a bit dificult to draw conclusions without seeing stock air box results as well -regardless of what exhaust's on it.

Richard

[mopwer]

Originally Posted by J-1

Problem solved... Vacuum pipe

Which vacuum pipe. My graph looked the same.

Greg