"Ray's AKA demonfire's XR4Ti build up"

[Ray]

Fun day yesterday with 4(!!!!) local XR's showing to attack cones.

Dr. Anglin machined me some cone killing mods - any guesses as to what?

[DSPXR4ti]

NO! but your pissing me off by making me guess are you meaning the little spikes on your air dam.

Ben

[Ray]

Yes, of course. Those are little spikes that he custom CNC milled for me, for no other purpose than to intimidate cones to get out of my way. And, by that, the only cones hit yesterday were when i decided it would be a good idea to come thru the finish box... backwards... then put the car into reverse and drive out of the finish box (which included a 90 degree)... in reverse.

[DSPXR4ti]

Very good because it looks as though you have the Mad Max look, very cool. now you just need the turbo to stick out of the hood so you can see the blades turning, to be super cool.

Ben

[Ray]

I have not been good at keeping this thread up to date- sorry. I haven't been doing too too much to the car this season, just racing every other weekend. I have plans for winter, and given that mornings are now getting cooler here, i am starting to plan.

Having a spare motor on a stand for mock up will come in handy.
6061 aluminum 4" ID velocity stack.


Where is this going? here is an idea.




I am planning on doing a plenum around the the stack lower portion of the stack tig'd to a flange to bolt to, so it'd still be upper / lower. Plenum volume i'm targeting 2.3 liters, might be a little shy. Going to shape the lower to blend into the stack.

Thoughts?

[RatFink]

Thoughts?

I think you are on to something. I have always felt the XR's don't have enough, well, really no plenum volume. 2.3 liters may be on the big end of things, but I think you are heading in the right direction.

[michaelb]

Like this with your velocity stack?

[Ray]

Sort of, yes.

[Jon L.]

Ray, been a while.. I've got a question for you in my journal thread

In short, can you give me details on how you plumbed the side vent on your Esslinger valve cover?

Thank you sir

[Ray]

Sure, Jon:

Removed PCV, PCV hose goes to an aluminum 1 quart overflow i made with a filter attachment.
Valve cover vent comes out the side, does a 90 degree up (to keep liquid, non vaporized oil, in) then goes to the same overflow tank.

That's it.

[Ray]

After a few months of really not doing any car stuff, i decided to start the manifold. Dr. Anglin was kind enough to cut the flanges off of a spare upper intake manifold, cut out the inside, cleaned up, acetoned, and tacked in. Using a hammer and a dolly, shaped the stack to mimic the shape of the flange itself.

I'm really surprised at how well the stock cast aluminum welds to the 6061 velocity stack.

[John Brennan]

I hope you will radius, rather than knife-edge, the openings in the lower intake. Bo once schooled me over on TF as to why radiusing is so much better, but the short version is that you have to think of the air transitioning laterally from one hole to the next as the cylinders draw air in turn-- radiusing encorages a smooth flow, but knife-edging causes the air to trip over the edges and create turbulence-- the air doesn't flow straight down.

It was quite enlightening.

[wicked93gs]

Thats going to be one large manifold...will it fit under the hood? Even mine is close...the only reason it might fit is because its on a 45

This is a folvo conversion but oddly the stock valve cover and folvo valve cover sit at the same height...these ITBs have a 4" "mailbox"(by which I mean rounded top) sitting on top of them. It comes out to about 3.5" above the valve cover. It looks like it will barely fit...may even have to trim some hood bracing. My point is...watch that height over there...the "power bulge" tends to end where its most inconveinent to do so.

[hEaT]

Nice work Ray. Finally something to let that head flow.

I hope you will radius, rather than knife-edge, the openings in the lower intake. Bo once schooled me over on TF as to why radiusing is so much better, but the short version is that you have to think of the air transitioning laterally from one hole to the next as the cylinders draw air in turn-- radiusing encorages a smooth flow, but knife-edging causes the air to trip over the edges and create turbulence-- the air doesn't flow straight down.

It was quite enlightening.

Agreed John. Airplane wings are radiused and not knife edged for I'm ASSuming that same reason; laminar flow.

[Ray]

Yeah, radius leading edge, knife edge trailing edge. Will do. I'm going to use the lower manifold that is on the car.

And yes, it's going to be a fairly large manifold - if my measurements are correct, i will have about a 3.5" plenum, including the v-stack, which will give me about 1" to hood clearance. again, i'm still in the just starting to fabricate stage... Original thoughts were a desired final volume of about 2.3 liters - which is about 140 cubic inches...

The OD of the v-stack is 7" - if i step up 3" from there that is a 7x7x3, or 147 inches - so the idea is to have something that is basically only as big around as the outer dimensions of the stack itself - the volume of the radius of the stack will remove some, so i'm going to go to 3.5" - also to allow more flow into the plenum itself from the TB, as the TB will be somewhat low to allow for hood clearance.

It's all mapped out in my brain - just hard to put into words.


Also, i will have a 90 degree rotated intake for sale, so long as this fits.