I am sorting out my Turbo set up on the 20B at the moment i am looking at fitting a T51 (Kia/SPL).

What i would like to know with an Extended port 20b (Exhaust sleaves have also been done) what Turbine AR would you guys recomend? i was thinking somthing like 1.15-1.3?

I know this is a often asked question but what BHP would you expect?

Thanks.

 

Mine with a street port has a T-76 Q-trim and 1.32 turbine. I wanted to have boost come on later, around 4K, but have more total available power throughout the rest of the powerband. On the street hopefully I wouldn't be spinning out constantly when under the 4K mark and just have the motor powering me, like an NA. I'm assuming (big guess) that it should be in the mid 600 RWHP range. I was shooting for 800hp flywheel as my goal. If I actually hit it, great

I think the turbo you are looking at makes mine look really small. Probably stick with a smaller A/R like a 1.0-1.15 or thereabouts so it will make boost in a decent power range, not high into the 4-5k range before it starts coming on. Unless you have the same goals as I do.

 

I'm just curious, but why are you interested in that turbo if you don't know how much power it will make, or how well it will work with a 20B? Sorry, but I'm just interested in things like that.

Although I have never seen a compressor map, I hear that the T51 KAI flows about 80 lbs/min max, which is comparable to a Turbonetics T72. However, the 80 lbs/min rumor could be wrong, so if you know what the max flow rate actually is, then please post it.

 

I'm running my fresh 20b in on a very crudly piped up set of stock twins but i am looking to run 600rwhp with the right set up?, i have had a look at other 600bhp cars (Supra's,Skylines,300ZX's etc) and they all seem to be running T51's.

Basicly i havnt got the Experiance in Tuning 20B's and there for am Guessing to a point.

I guess i'm a bit of a BIG is good but BIGGEST is best kind of guy (Hence the 20B)

LOL

Chris

 

So you're obviously making an assumption based on no known cfm flow rates of both your motor nor the compression map of the turbo you want to use. Using those other motors are a generally uselss comparison because you need to know their flow rates at a given rpm before you can compare your motor. Tuning has nothing to do with it, you're looking at flow of air.

My best advice is to purchase a good turbo book (Corky Bell has written a great one) and learn how to calculate flow rates of your motor. Then get a compressor map of the desired turbo and see if it matches up or not. You could also ask a turbo supply company that has experience with 20B's for their recommendation or even 13B's and multiply that number by 50% (not the best solution but gets you somewhat close).

Or better yet, since your motor is running, disconnect the twins you have, and put a flow meter on your inlet to your throttle body. Rev the motor at given rpm values (in increments of 500 or 1000 rpms) and see what the flow rate is of the air it is pulling in. That's the easiest and best way to know what the engine is doing for air flow, actually measure it.

I believe I've heard that the T51 SPL will put you more into the 1000HP range and is more of a drag car turbo and hence, not very streetable (just 'net rumor). The Kai is smaller and will build pressure faster but is still very large.

Most of the 300ZX's and TT Supra's that I've seen are using T-60, T-66's and T-88's but I have only seen a handful.

 

Ok i've E-Mailed HKS for the Tech Data on the output of the T51 series.

Is there any write ups on the net about selecting Turbos?

Can somone explane Exactly how i compare the Information?

Chris.

 

OK, so you were basing it on the output of other engines using that turbo. That's logical. Thanks, I just like to know marketing trivia like that.

LOL, a surprising number of professional race drivers and mechanics simply ask the turbo manufacturer which turbo to use. This really shocked me at first, but I guess that's probably the best method.

Corky Bell's book is pretty good, although it doesn't cover the rotary engine. It is definitely worth getting.

http://www.gnttype.org/techarea/turbo/turboflow.html
http://www.opeltuners.com/turbo_efficiency/article.html
http://www.majesticturbo.com/compression.html
http://www.turbofast.com.au
http://www.rapidline.com/calc/turbo/pctcmap.htm

BTW, be sure to double the displacement of a rotary engine when entering data into formulas or charts designed for a 4-stroke piston engine. This is because a 4-stroke engine only fires half of its rated displacement per revolution, while a rotary fires all of its rated displacement per revolution.

 

Thanks Evil! I did my own calc's by hand before but that helped clear a few details for me...

 

OK, I've done a bit of reading.

What would i need to do to my Internals to handle 700bhp (flywheel)?

To date i have an uprated Oil Pump,Staitionry gears and 3mm apex's, i have also Extended ported it and changed the exhaust sleves?

What else would i need before i go with a big Single?

Thanks.

 

injectors, ECU, good intercooler.


The internals will be fine for 700bhp..


-Zach

 

... racing transmission, 2-disk clutch, custom driveshaft, upgraded rear end, large rear wheels/tires and appropirate flares or body kit, scattershield, driveshaft hoop, larger fuel lines, competition fuel pump(s), FPR, high-flow fuel filter(s), and a lot of other things that I can't think of at the moment. I hope you have a lot of cash to support putting all that hp to the ground.

 

Hey, he didn't say he wanted it to move, just get the engine to run

 

LOL, So the engine its self should run 700bhp (flywheel) ok?

I have noted the other mods and will be doing them whilst its off the road for winter.

What Diff/rear end do you recomend?

 

dont forget tranny cooler and especialy oil cooler,blow off valve, turbo timer, and you could always try runin avgas, it all depends on how diehard you are

 

Nothing that bolts on will hold the torque.. Your cheapest route would be a ford 9"


-Zach

 

The stock TII rearend is real strong. Plus you could always beef it up by going with a Kaaz or something comparable.

 

um, the stock TII rear end will not hold 700ft/lbs of torque for very long. but before that you are gonna snap your U-joints.. The stock tranny can only hold ~400ft/lbs of torque simi-reliable..


The other option would be a Kaaz and chromoly halfshafts, and a upgraded/custom driveshaft. but it is gonna be costly..

-Zach

 

Unless it is a drog only car, I wouldn't wanrt to put a straight axle in it. The ford 9" would definately NOT be the cheapest route. Stay independant. Kaaz rearend 700-900 bucks plus 250 to have a shop install it, if the rearend is already out of the car.

 

Umm, I don't think he said 700 ft lbs of torque, he said 700 hp at the flwheel which would be roughly 500 ft lbs of torque i'm guessing. Why put more money and work into it a straight axle and have a car that wont handle as well, unless you are only drag racing. BTW, Ford 9" also requires a custom drivshaft.

 

I agree that a 9" is not the best handling, but it is a cheap route. Like i said it should be well under $1K to get it in the car. but you will still need a beefed up tranny and driveshaft.

Anyone know the torque rating of a kaaz?

 

I got a little confused, i was thinking this was another thread where they guy wanted ~700-800RWHP, and that is why i recomended a 9"


If he only plans on running ~400-500ft/lbs of torque kaaz and chromoly half shafts and upgraded driveshaft would be the best route.



-Zach

 

Kaaz rearend is essentially bulletproof. The case would crack before the diff itself goes and this is more of a problem in 3rd gens than in 2nd gens. Chrome-moly halfshafts are roughly $800 a pair but you shouldn't need them or a custom driveshaft unless it is an all out drag car where a ford 9' would be best fort sure.