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AFR worry after new inlet manifold
bi22le - 18/12/16 at 10:43 PM

Im coming to the end of completing my new inlet manifold ( ill do a full build blog and pics once completed) and Im still worried about varying AFR across the different cylinders.

Im using a pulsar plenum with a flat backing plate that fits straight to my ITBs. There will be minimal trumpet radius at the ends to save space as I want to fit it under the bonnet. This also means that the cylinder furthest from the air feed has just under the diameter of the ITB clearance / height. It is tapered but I am worried that the closest cylinder may run lean and last rich as the amount of air decreases as it passes each ITB mouth to get to the next cylinder.

I have a closed loop Omex 710 management system and the plenum is quite tappered but Im still worried.

Has anyone experienced this as an issue? Running a small capacity plenum with inline air feed?

Conmments and thoughts welcome.

[Edited on 18/12/16 by bi22le]

Ugg10 - 18/12/16 at 10:48 PM

Slightly off topic, you say you have omex 710 in closed loop, can you u2u me details of this setup as I was not aware it could do that. I have an innovate lc2 plumbed into it so think I have the kit to do it.

mark chandler - 18/12/16 at 10:57 PM

Point a digital thermometer at the exhaust headers, if they are all similar then you do not have a problem.

You also get some ghastly manifolds on older cars, these still managed 100,000 miles without issue.

bi22le - 18/12/16 at 11:12 PM

quote:
Originally posted by mark chandler
Point a digital thermometer at the exhaust headers, if they are all similar then you do not have a problem.

You also get some ghastly manifolds on older cars, these still managed 100,000 miles without issue.


That is a great shout. I have a thermal IR gun. Lean = hotter right?

theduck - 18/12/16 at 11:15 PM

The gtir plenums is considered a very good design so if anything should give you even distribution of air to each cylinder.

bi22le - 18/12/16 at 11:23 PM

quote:
Originally posted by Ugg10
Slightly off topic, you say you have omex 710 in closed loop, can you u2u me details of this setup as I was not aware it could do that. I have an innovate lc2 plumbed into it so think I have the kit to do it.


U2U me what you need to know and I'll try to find out. I don't have the software to read the ECU. All I know is the lamda sensor is wired directly into the 710 and I was told it is running closed loop when I bought the car years ago. If its possible then the previous owner would of nailed it. He was a long term contributer on here and has got the VVT also working c from the 710.

bi22le - 18/12/16 at 11:26 PM

quote:
Originally posted by theduck
The gtir plenums is considered a very good design so if anything should give you even distribution of air to each cylinder.


I would tend to agree but a lot of the magic is in the back plate which adds volume and has contours that feed air in. It's also for aforced induction engine and im running NA for now.

Ugg10 - 19/12/16 at 08:49 AM

quote:
Originally posted by bi22le
quote:
Originally posted by Ugg10
Slightly off topic, you say you have omex 710 in closed loop, can you u2u me details of this setup as I was not aware it could do that. I have an innovate lc2 plumbed into it so think I have the kit to do it.


U2U me what you need to know and I'll try to find out. I don't have the software to read the ECU. All I know is the lamda sensor is wired directly into the 710 and I was told it is running closed loop when I bought the car years ago. If its possible then the previous owner would of nailed it. He was a long term contributer on here and has got the VVT also working c from the 710.


Many thanks, will do later tonight, will have a read of the manual first, it may be that you can run closed loop but not the self learning type as used by Emerald.