BLUE TII

iTrader: (9)

Thanks!

Full-Race Geoff

In response to your question, from BW's #1 in command on the EFR engineering team:


"Hi Geoff,

Perhaps it's a nuance of rotary engine rotor/port/spark timing that I'm not familiar with. On 4 stroke piston engines both gas and diesel, it would be very unusual for light-load EGT's to be that high (1000C) unless timings were very atypical. In the case of this rotary, I'd imagine fuel is still burning as it leaves the port to cause such high cruising EGT.

Needless to say, application practices differ for aftermarket since ductile or HSM iron housings are never used above 780C in OE! But you see this all the time in the aftermarket. In the turbine design world, we limit Inconel EGT to 980-1000C. Higher than that gets MAR-247 as the TW material. "


so I have to ask, do other guys see 1000C at cruise? that seems unusually high especially at light load/cruise

Howard Coleman

iTrader: (6)

my cruise is 1250 F, 676 C. AFR 14.1. i prefer to be a bit richer than stoich as i find around 14.7 my pedal gets a bit on the weak side. timing is low to mid 30s w no split. rpm 3050 at 73 mph w my T56 in 5th. gasoline.

thewird

iTrader: (8)

I generally see 1300-1400*F highway cruise on a healthy engine for cars that have EGT's. 1000*C (1830*F) cruise means something is seriously wrong. Those temps should only ever be achieved under heavy load at high RPM on an aggressive tune.

thewird

Full-Race Geoff

thanks guys, those numbers are consistent with what Ive found on most of our engines.. no reason to be concerned if you arent melting/cracking the BorgWarner Airwerks turbine housings IMHO... spark ignition engines simply can not put the hurting on a turbo like a diesel with big fuel system. the stuff we've seen diesel tractor pull competitors do to those things is incredible.

Turblown

iTrader: (12)

Here are some initial 8374 results. I believe this car has a time attack event this week, and sooner or later will do some more 12 plus hour enduracing racing. It will be put to the test durability wise.
http://m.youtube.com/watch?v=RDRXa_A...ure%3Dyoutu.be

Enigmatic

That's my mechanic and his car! His dyno is known for being conservative, maybe 10%? *edit* I see it is mentioned in the comments at the end.

thewird

iTrader: (8)

348 rwhp at 17 PSI is pretty damn conservative.

thewird

Howard Coleman

iTrader: (6)

post 31 showing approx 340 rwhp is probably not at all representative of the 8374 output.

the turbo is a 6.6 sq inch compressor and according to BW's compressor map (see post one) and at 17 psi puts out 62 pounds per minute at SIXTY FIVE % efficiency...
which means it will do 8.3% more power than your typical compressor map that ends at 60%...

at 17 psi

504 SAE max assuming it can be driven to the compressor map edge.

something is probably not optimized here.... do not associate it with the turbo.

howard

PDF

I agree with Howard. There is something holding back hp in that particular video. I'm picking the exhaust is restrictive and choking the engine. a) because the car is too quiet, and b) because 16psi boost should be reached before 4000rpm. BW turbo's are all about turbine flow and need a larger exhaust than their Garrett based P trim counterparts, particularly when the wastegate is piped back into the exhaust like this one must be.

Turblown

iTrader: (12)

The car has a 3.5" exhaust system, and last I checked it was running an open TurboSmart waste-gate. The rest of the basics are done; street-ported, direct fire coils, Adaptronic E1280S( tuned by Andy), Vmount etc etc. Keep in mind this is an endurance race car, reliability is key. Its running in the WTAC in a few days;

World Time Attack Challenge | 18th – 19th October, Sydney Motorsport Park, Australia

I've always seen lower dyno hp numbers from across the pond...

rx72c

iTrader: (8)

Our HP numbers never seem to be as high as what you guys achieve. Didn't mention what fuel?

Also car is barely climbing the front roller so power figures are not going to recorded properly.
Straps are too tight.
16psi at 4000rpm is not bad but Boost response on the dyno does not show response.
On the road/track response is what counts.

BLUE TII

iTrader: (9)

Yes, my local dyno is DynoDynamics as well.

My EFR 7670 dynoed 369rwhp on the Dyno Dynamics (corrected).

Drove to dynojet a couple days later with zero changes and got 419rwhp uncorrected (.983 CF so should be 1.7% lower corrected).

We had to set the Ramp Rate on the DD to 85 which I believe is 8.5km/sec acceleration to get the spool the same as on the street (worked with my old turbo and EFR).

Our local dyno is not loading enough after 5,000rpm and boost drops faster than the street and Dynojet
You can actually hear the engine note go flat on the DD for a full second and then pick up again. IDK how we are going to fix the loading issue yet.

Warrior777

iTrader: (3)

Great info!

BLUE TII

iTrader: (9)

I learned I can write "scripts" or little dyno programs for the Dyno Dynamics. I will write one that alters the ramp rate every 500rpm to match a 4th gear pull on the road.

That should get the loading perfect.