Found the engine is not getting enough air.

[TransAmDan]

Dring my various tuning sessions, I seem to loose power around 5500rpm. Spark timing is close to 5000rpm, fuel is spot on.
I know my 4inch air intake is a large upgrade, cant be a restriction there. The air box dosn't quite seal to the hood yet, but soon will do.

The top nostrils with even the mesh removed will increase flow a little. I was hoping to relay on this entirly for the breathing of the engine. however looking at calculations its not going to be enough.

At present its not toally sealed, so is getting little air from the sides of the airbox. However when it is totally seal for the full effect of ram air. These figures above show that not enough air is available, the engine will be consuming around 700cfm. My CFM will increase with speed, however will be suffocated when giving it beans at lower speeds.

So I need to cosider using the bottom air intakes. I will need to gut hold in the underside of the hood.

I will also need to add some scoop type bits to guide the flow.

I need to avoice the bonnet catch and bonnet release.

Scanned in the parts to start working things out.

 

[TransAmDan]

If I use the bottom holes i should be fine.
Going to be in interesting challenge. Looks to be flowing enough air through the holes now when incorporating the bottom scoops.

Can certainly flow enough now to supply the engine when giving i some beans. Should cure the issue i was seeing at 5500rpm.

 

[TransAmDan]

Ofcouse with the seal box, the air pressure on the 4 air scoops will help force air into the engine. This will also result in HP gains, not huge, but its a free gain.

Going to be a fun challenge getting all this in. Got to do all I can if I am to race Darren at Santapod.

 

[TransAmDan]

By decreasing the density of the mesh we can improve air flow. The original was looking aroynd 40% of the air flow. Would bve great to get that down a lot lower.

Made a 3D scan of the original

Wanted to check fitment, so just drew up the out edge for now.printed the outer edge.

Then printed for a test fit.

The back is smaller than the front so needed to model that in too.

Drew a bit more to the model.

Brought it into the 3D package and added some colour.

Printed out pretty good.

Fits great

Not sure if I'll keep the yellow. I do have Purple(not in ABS, its in PLD so likely to deform at 50c), it may be an option, Only cost 74p in material to print the pair.
I do need to work on the air cavity begind this grills, this is what joins to the 3D printed air box. Add some air directional stuff, and will involve some fibreglass cutting on the under side.

 

[saleen 192]

Make hexs a tad smaller
. As you say not sure on yellow . But apart from really good idea looks smart for 1st design.

 

[TransAmDan]

Got my saw thingy took out. Attached the bonnet. The air comes through a letterbox hole. This can be extended to the top. Of the hood. Air box now designed for that.

Hole far bigger now. That saw was awesome, cut through fiber glass too easy.

Air flow improvements are progressing.

 

[TransAmDan]

Little more trimming one each side. Lines up perfectly with the seal on the sides.
Needs a little ramp on the inside of the hood which will line up with the air box seal along the front.