Gonna well the **** out of the old engine when I’m done scavving it. Lol

 

Sell, not well, goddamn autocorrect.

 

MBT is minimum timing for best torque. Basically you put the car on the dyno, set it to run straight across a single row, and advance the timing until the power stops increasing (or it pings). That's MBT. Then you back it off from there by a bit for safety.

What the actual MBT value will be depends on a whole bunch of things (backpressure, cams, cam timing, boost level, RPM, etc), so you pretty much have to determine it experimentally for each engine config. That's basically what 80-90% of power dyno tuning is all about.

--Ian

 

100kpa row should generally be 29-30 ish between 5000-6500. Taper down towards lower RPMs.

Cruise cells at low load can be 40 or more for fuel economy (not so important for a track car).

 

Yup

 

18psi sure is a good number aint it?

 

Everything looks super solid to me. The ziptie between the oil feed line and the crankcase breather is going to last about 45 seconds on track There should be enough length in the oil feed line to route it around the outside of everything and around the forward edge of the heat shield.

Aside from that, there are a ton of nice details here. Well done.

 

Thanks. That zip tie was temporary while the heat shield was built. I've since re-clocked the oil line so no support is necessary. Do you have a pic of the routing you usually use? Mine is still going backwards towards the firewall

 

Nice build. I should post pictures of my EFR build too. I am lazy.

How are you feeding air to the oil cooler in that location? I was thinking about placing mine there to have better flow for radiator but I am giving my set up a try first. Oil temps are great on hard canyon runs, no track yet.

 

 

Your build looks really cool. I am curious to know on your setup with as much air going in and going out of the skunk2 .5L plenum spacer would yield any gains.

 

Looks fantastic.

 

LOTs of great ducting work there which I'm going to borrow for my eventual ducting work.

I do have a couple of suggestions though which may or may not be beneficial so please respond accordingly guys, I tend to be paranoid and over-analyse things:

1. The intercooler bounces around a bit due to its horizontal supports being silicone hoses.

In some of those photos, it looks like the intercooler touches your intercooler or is very close to it.
This means that the intercooler will be constantly banging against the ducting (this may damage the ducting and enlarge the bolt holes).
You could either add a rubber edge to the ducting where it contacts the intercooler or, on the base of the ducting, add 2-3 U-shaped brackets that the intercooler can sit between to limit its horizontal motion (or match the ducting's horizontal motion).



2. The gap above your intercooler will mean that more air will flow into that gap to the radiator, over the intercooler, and you'll end up with positive pressure between the intercooler and radiator.
With positive pressure, even less air will flow through the intercooler so it will be less effective.

You can minimise this by adding a "roof" on top of the intercooler that angles downward to the bottom 3rd (or lower) of the radiator, creating 2 chambers between the intercooler and radiator.
The top chamber will flow fresh air to radiator - that's good and the high pressure generated will not affect the lower intercooler chamber..
The lower chamber will flow pre-heated air that has passed through the intercooler to the radiator but the lower chamber will be less pressurised than your existing solution so more air will flow through the intercooler.
If you vent this chamber straight under the car, or to your brake ducts, you'll get even more air flow through the intercooler.

 

Whoops, ... stupid double-post!

 

There's a lot of rings in that room. Who's shooting the wand?

--Ian

 

While reading this post I was eaten by a grue.

 

The intercooler is rigidly mounted to the chassis it's not being supported by the intercooler piping. The ducting is also rigidly mounted to the chassis as well if you look at the photos. Could the entire design be further optimized? Yes. Is it necessary for the 250-300hp range? Unlikely. I appreciate the feedback though

 

Thanks Andrew.

 

Gotcha regarding the intercooler - I didn't notice the intercooler brackets above its barbs that bolt onto the chassis and assumed it was being suspended from above (which it can't be now since you've removed those sections that are used when mounting an intercooler this way).

Regarding air flow/pressure, it may not be an issue but keep it at the back of your mind if you start noticing heat-soak issues (ie. lack of power in one track session vs the previous one, most likely to occur on hot days).
This was one of the issues that was pointed out to me when I installed my BEGi air scoop which funnelled fresh air from under the intercooler to the radiator - it made sense to me that less air would flow through the intercooler due to the positive pressure between the intercooler and radiator so I removed it (another reason was that it hung quite low so was prone to being ripped off every time I went over a speed hump).

Also, what thickness is the aluminium that you're using?
I'm guessing 2.5mm (0.0984252") or 3.0mm (0.11811") - (sorry, I don't know how to express small measurements in inches, Australia moved on from the antiquated UK imperial system in 1974).
In the past I've used 3.0mm aluminium when I need wall rigidity but these days find I can get away with 2.5mm which is a lot easier to bend, weighs less and is cheaper.
With 2.0mm (0.0787402") aluminium, I find I need additional bracing to eliminate flexing.

 

Almost done here. Opted to use the splitter mounts from Racebred with an adapter plate to the chassis and they work great. Splitter mounts shown backwards in photo.

Splitter still had a bit too much flex so a small supporting aluminum frame was made.


New overflow tank almost done.