08-02-2014, 10:06 AM
Join Date: Dec 2007
Location: Texas Hill Country
Total Cats: 16
Aluminum tubes; as a should be well trained injuneer by now, I can't quite show why a steel tube sheds virtually the same heat as an aluminum tube. Best guess is the hurricane overwhelms the heat transfer coef. But, but, but, it can't. Or can it?
BIC has a grid we use to streamline the core entry when the need arises. The "need" comes from two sources; so much boost the core needs more strength, and/or the flow is so high that losses get a bit out of hand. For the Miata, cutting the flow loss by maybe 10% will prove nearly zip. Decidedly not worth the trouble.
We (BIC) does make an IC for a Lotus performance parts seller.
The remote gate is worth a noticeable amount of power. Plus, boost creeps go away. We've cured (?) boost creep with the stinking integral gate 27 times. Every time we change something for a tick more flow, we're right back in creep again. Phone calls regarding creepers are not the high point of the day.
Take a look at the flow paths through the system from head to dnpipe. Its all a nice even shot to both gate and turbo. The bends are generous and the path is smooth. This is not a gate welded at a right angle to the flow path atop the turbine housing, thus closely emulating the same old integral thing. Plus, the empty pocket at the original integral gate gets plugged and baffled so the exit flow is not screwed up.
The dnpipe has only two bends. I made the dnpipe first so it could lie in one plane. It is straighter and has a gob more clearance everywhere. Add a couple adjustments; it can swing 5 degrees at the turbo, lengthen/shorten two inches up/dn, and even change overall length. Of course, the tube tapers outward from whatever the turbine exit dictates to a larger section at the cat entry, just as any honorable dnpipe ought to do. Also made the w/g vent tube longer and arranged an easy, yet supported, dump to atmo if desired. Surprisingly, that atmo dump adds about 22% to the flow area. Then put a brace from pipe to tranny.
The turbo is raised up an inch or two. Its no longer necessary to cut the frame ledge for anything bigger than a 2554. No cutting even for 50108. That'll teach 'em to copy.
With the higher turbo position, a hood shield is provided, although not really needed. Its on the hood (naturally). There is also shield for the bake stuff.
Every time I calc fuel available and measure the actual fuel pressure, I come up with 234 hp a bsfc of .55. Would it not be reasonable to lower the boost with less octane? We will send a lighter spring for the gate and force its use with verbal coercion.
The reflash technique can use injectors up to 450 cc/min. We'll try that very soon.
The original four cars have weld el manifolds. In my view, these are not good enough and require too many lousy/difficult intersections. I've got the pattern and core box done for a pretty nifty little casting. Its the first time I've tried a specific feature in the collector, which a casting permits. This is taking the oval shaped ports coming out of the head and twisting the oval 90 degrees as it heads for the collector at which point it is much easier to merge into a nice shape. The runners also taper 10% over the distance to match what the turbine housing initially does to the velocities. Now, tell me that's not fun. Except, of course, for a sawdust allergy. Ductile iron, of course. The casting is only for the 1.8's, btw.
You need to see the cool air horn on the front of the turbo. We found a way to press it out of a 2.75 inch tube with the use of a hydraulic press. Different piece for a flow meter, of course, had to machine a half donut and stuff it into the filter.
Same old well anchored stainless braid oil/water lines.
I've probably forgotten the rest of it....... thanks for your indulgence.