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Hello,
I will be building a new buggy next winter(4 seater so grandkids can ride too) I am currently in the planning stages and looking for advice and knowledge.
The parts I currently have are:
Aluminum super case
Cima 94mm b p/c (a nos set from the 80's)
84mm Empi crank
5.5 Empi rods
AA 501 heads (42x37 valves)
Engle FK43 cam

I would like to make good torque and plan on 5800 rpm redline.
This will be used in the woods running trails and climbing hills in KY, WV and Ohio.
I am planning to limit boost to 10lbs, this motor will be EFI(microsquirt) and intercooled, would like to run at least 9to1 static compression and can run E85 if needed.
I am not opposed to different heads and cam.
Was considering a T3/T4 hybrid turbo.
Thanks
Kenric

Sounds like a lot of fun to me!

Any suggestions on what trim T3/T4? I am thinking about 57 trim but interested in hearing what has worked for others?
Kenric

I like to err on the large side so you land somewhere near the center of the turbo's max efficiency island. Outside that max efficiency, you just blow hotter and hotter air even though boost goes up. I noticed this with some of the smaller turbos I have ran, even though they spooled faster. Power seems to fall off on the upper end. I really liked my 62mm T3/T4 on my 2276 as far as upper end power levels and super flat torque.

So lets say your motor, conservatively NA, makes 165hp.

165hp + 10psi of boost on average will get you to say 275hp according to calculator below.

http://wallaceracing.com/hp-blower.php

Then take 275/165= 1.68 for your approx pressure ratio.

Then look at the map for 57 trim T04, go to 1.68 on Y axis, then your HP (which is roughly equal to flow) on X axis.



This gets you close to max efficiency, which is of course theoretical.. but in my experience really close to reality of how the turbo will perform at a given boost level and power level. Pair that with a stage3 turbine wheel and .63 exhaust housing and I think it would be plenty for that lightweight buggy.

Yes, the above turbo will make 400+ hp but it will be super hot air and not very efficient. So when shopping for a turbo or compressor wheel, the max HP does not mean much to me. I want to see where it is most efficient and therefore less hot air, then choose for that range if that makes sense.

Not sure if you are sticking with that cam, but I would suggest an fk7 for the rpm range you want. I was running a LBC2 cam which is very close to the fk7 (duration at 50 was 242 the fk7 is 244). I made 260 at 5800rpm with the lbc2 and it had torque down low to 1300rpm.