Tbird

Hey guys, I am brand new to rotary. pickup up an 87 in decent shape and plan to do a few things to it..... I have done a few v8 turbo's and 4 banger turbos... So I beleive I am very informative when it comes to boost ect..... anyways I dont know where to begin asking about this engine..

I am seeing some guys saying the 13b can spool a turbo with an exhaust a/r of .80 and bigger without a problem.... wow to me this is a big turbo for a piston motor.. to me it would be very laggy on alittle rotary motor thats why I am asking for an explanation on...... what is to big or to small for these..... say for a stock 13b turbo engine what would be a good upgrade??? I was thinking about doing a T70 setup at low boost but would like to learn alittle more before going out and blowing money. thanks

J-Rat

iTrader: (2)

Well, I have spooled a .96 AR on my stock port using a t-61 blowzilla. Made about 437 wheel. Now I am ported on the same turbo and running 490 wheel.

Reason for the large ARs is because the rotary exhaust volume is much bigger then on a piston. There is no wasted movement, and each face of the rotor is performing one section of the compression cycle. On a piston, there is one wasted stroke.

Tbird

wow thats cool.... you did this on a stock 13b turbo2 motor??? what would be a good size to spool at around 3k ish

Tbird

Also what needs to be upgraded in the engine to be able to hold up to some good power

J-Rat

iTrader: (2)

I was in positive pressure by 3k, but full boost wasnt until around 4200-45000. If you want faster spool, you could probably back down the AR a bit.

Define "good" power..

Tbird

really would like to see over 400hp or enough to take out some 600cc bikes on the highway

nik

You probably should consider a different compressor if you want to run low boost. If you just want 15 psi or so there are better choices in terms of response/powerband. What exactly do you mean by low boost?

Tbird

18-20 i pretty low... depending on what these engines can do Id like to see 25+ on race gas, meth injection

nik

Ok, then you are in the right direction with the T70

RETed

It's also because you're dealing with just two exhaust pulse per "RPM".
4-cylinder has 4 of them.
8-cylinder has 8 of them, or 4 per bank.
The more pulses you have, the more "diluted" the exhaust pulses get in the exhaust.
Since the 13B runs just 2, you get two really hard "hits" from those two exhaust pulses.


-Ted

13b4me

And with porting the hits just keep getting harder. A good peripheral port is like a punch to the chest.

J-Rat

iTrader: (2)

Presently, I run 25 PSI with Race gas and Alchy injection.

Patman07

how much power you making s4 or s5 stock internals i assume?

cpubugs

Thats easy no major horse power needed. Just open your door, or slam on your brakes, you can take out motor cycles all day... At least here in FL, most of the kids riding crotch rockets are morons. they drive like idiots and they wear shorts, tshirts and no helmets.. My favs are the ones that is ee wearing the above and flip flops... Or shirtless... really how dumb do you have to be... Sorry, i love crotch rockets but some of these guys are morons... lol

HAILERS

I was in positive pressure by 3k, but full boost wasnt until around 4200-45000. If you want faster spool, you could probably back down the AR a bit.
************************************************** ****JRAT'S WORDS ABOVE

I've a suggestion. Either fix that slipping clutch or keep your foot off the clutch so it'll release better. Forty five grand. My, my. humor