Turbo sizing question
 

So I'm going to be turboing my 13b eventually and was trying to get to the 500-700 range, I know the output of a rotary is more than a piston, atleast at higher rpm range, would a g30-770(2.0L to 3.5L) have too much lag. Any suggestions?

G30-770 looks like an alright turbo for 350-450rwhp on a rotary. Not what I would choose by any means.

It should spool amazing with the tiny exhaust side it has if it doesnt choke the rotary out. We have yet to see if the new tiny G series exhaust sides work as well as advertised on a rotary.

For 500-700rwhp on a rotary you are looking for a turbo with a compressor in the 90-95lbs/min flow range.

EFR 9180 is a popular 95lbs/min capable turbo currently that has little lag for its size and a generous size exhaust side.

If you're shooting for 500-700whp then I sincerely hope you've overbuilt the hell out of your motor.

Like blue said though, you'll need a BIG turbo for your goals, additionally you'll need lots of fuel, solid spark, e85 or WMI and a good computer if you want to make that power reliably. Plus you'll want to upgrade the rest of your vehicle to suit... it's not a matter of just slapping a turbo on an NA motor and sending it, you're probably looking at $20k plus on the low side to do mostly right.

If a built piston motor can expect 10hp per lb/min of turbo flow, than a well built rotary can expect roughly 7.8hp per lb/min. You may want to go back to the drawing board and adjust expectations.

Im aware 700 is a far stretch, and im going to dowel the irons and housing, etc. Im more so hoping for around 500 but I guess it doesn't hurt to hope for higher. besides the machining, everything else I'm going to do like the turbo piping, tuning, wiring, etc

500 vs 700 are 2 majorly different setups.

for 500(ish) i would probably shoot for an EFR 8374 even though the 8374 will probably be pushed to get those numbers. i havent seen the 8474 in action but the 9180 or 9280 is probably your best bet for a 500+ setup but expect some lag

You should speak with Skeese. He built and sold a 700rwp+ 2 rotor.

I agree that 500 and 700 are different animals though.

Thanks for all the responce, Ill probably go with the 8374 and stay to the 4-500 ish range, I'm just going to work on some of the drive train upgrades while I have it apart for now.

Trust me my guy, 8374 rotary with the right injectors, spark, IC, fueling, and ECU is A LOT to handle on the streets. It's about as far as I'd go on a street car. My car makes it reliably and I could not even imagine 700. I want no parts of that monster.

I have a G30-660 1.01 on my Renesis - they work well. Made 415whp at 15psi with ease . Emap was around 21psi at peak.

I would expect the smaller exhaust wheels to impact power less on a 13B-MSP Renesis because they dont have any intake to exhaust cycle overlap like the older peripheral exhaust port rotaries do.

That is good power for the boost and a lot of boost for 10:1CR Renesis

E85 for fuel I presume?

I see the thread.

E40 fuel.

So that is 360hp Mainline dyno corrected by 1.15 to get it to 415hp Dynojet equivalent?

The G30 AR 1.01 flows the same as the 8374 AR 0.92 and that turbo works pretty well .............It's also more efficient than the 8374 so I'd expect emap to be close to what you would see on the 8374 1.05. There are twin scroll T4 1.06 housings for the it now too....someone needs to try it on an REW !
Fuel was E40

No the correction is an SAE correction for temp/humidity/pressure and it's 1.15% not 115% . So this is a realistic number.

[QUOTE=Brettus;12492475]The G30 AR 1.01 flows the same as the 8374 AR 0.92 and that turbo works pretty well .............It's also more efficient than the 8374 so I'd expect emap to be close to what you would see on the 8374 1.05. There are twin scroll T4 1.06 housings for the it now too....someone needs to try it on an REW !
Fuel was E40

Do you know anything about the 1.01A/R GTX 3582R Gen II, and whether the V-band, or the twin-scroll is more effecient?

(Specs of it)

• Compressor Wheel Inducer: 62.5mm
• Compressor Wheel Exducer: 82.5mm
• Compressor Wheel Trim: 56
• Turbine Wheel Inducer: 68.0mm
• Turbine Wheel Exducer: 62.3mm
• Turbine Wheel Trim: 84

its 82 lb/min flow and 130,000k max turbine speed

[QUOTE=Doctor_25;12492511]Do you know anything about the 1.01A/R GTX 3582R Gen II, and whether the V-band, or the twin-scroll is more effecient?

(Specs of it)

• Compressor Wheel Inducer: 62.5mm
• Compressor Wheel Exducer: 82.5mm
• Compressor Wheel Trim: 56
• Turbine Wheel Inducer: 68.0mm
• Turbine Wheel Exducer: 62.3mm
• Turbine Wheel Trim: 84

its 82 lb/min flow and 130,000k max turbine speed

Edit: Disregard my last comment, I messed up the quote part, thought I edited it, ended up posting an entire new comment on accident

I'm pretty sure a twin scroll will be superior on a PP exhaust 13b for almost ANY turbo.
I'd go for a G35-900 over the GTX 3582R gen 2 though . It will spool better and have lower emap.

the G40-900 and 1150 are out now, looking good

the 80% center island has me rethinking a G35 purchase 🤔 wish it was a bit higher Pr though … the 70% efficiency width from 33 lb/min -73 lb/min @ 20 psig isn’t shabby though


https://cimg9.ibsrv.net/gimg/www.rx7...8ac3c3c34.jpeg




https://cimg4.ibsrv.net/gimg/www.rx7...063cbff64.jpeg



https://cimg8.ibsrv.net/gimg/www.rx7...b4cd34b25.jpeg

so you think the g-40 might be a better option with the bigger efficiency islands?

Well that depends on where you may be trying to fit it and also where you're real HP goal, overall mod,s and application goal is. Because you are still a bit vague on the details, and the details matter. Not a criticism, just that what you really are trying to achieve doesn't seem clear to me.

The G40 is about 2" longer overall than the G35, so there's that. Due to some inconsistency in how Garrett does the flange chart dimensions, it's not as easy to assess the width and height, but it seems they may be close though slightly larger than the G35 there as well.

In addition to the wide compressor efficiency range, the G40 turbine reaches as low or lower than the G35 turbines at the far left of the low Pr range (about 22 - 23 lb/min @ 1.3 Pr for the 0.85 AR T4, about equal with the G30 1.01 AR VB Brettus is using!), yet it also outflows sooner and greater than the G35 1.06 AR T4 turbine (the only G35 divided T4 choice) from there as well. The G40-900 looks like it has a lot of rotary potential for a 450 - 600 whp top end, but how responsive you want it to be on the low end, fuel type, porting, etc. etc. is all going to matter. Those are my thoughts any way, not really so much intended as specific advice for your situation. The G40 release just came out a day or two before I posted about it, so perhaps some people were not so aware of the choice.

Really interesting that Garrett thought they needed another series between the G35 and G42. Not only that ...but they went away from the single entry theme straight to twin scroll housings only. Would be interested to know what their thinking was .

They discussed releasing it a year ago as a G40-1000/1050

https://www.rx7club.com/single-turbo...150-a-1148267/


It’s also not the same -900 compressor assembly as the smaller G30/35; different compressor exducer, trim, and AR …


https://cimg2.ibsrv.net/gimg/www.rx7...2cdcf0bfe.jpeg
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G40-900 looks amazing for a 2 rotor.

Wish they would have thrown a 67-69mm comp inducer option in there too.

I doubt the response difference justifies that over the 71mm inducer of the G40-1150

It's not just the inertia of the wheel though, lower trim means more pressure at less shaft speed, should make a noticeable difference. I feel that flow rate (achieved on modern circa 68mm inducers ) would be a good balance for "I don't want to shred my factory case gearbox/aftermarket gearset the first time I go out" vs I put in a T56 may as well go to a G42 and 3 bar boost.

So then what's wrong with the G35-1050 with 68mm inducer and the 1.06 divided T4 housing?