EFR Internal Waste-Gate Discussion

[jacobcartmill]

i just got back from some street testing with the low boost actuator set to very little preload (2mm). so the wastegate pressure is ~5psi, and it creeps up to about 15psi and stabilizes.

i used the haltech boost control to set the boost straight to 15, but i had to run 100% wastegate duty, so i'm going to replace the low boost canister with the original medium boost canister and preload it to run 15 psi and do some fine tuning with the boost control solenoid.

the turbo response is great. had 15psi by ~3300rpms, and this turbo is physically bigger (comp wheel, turbine wheel, and turbine A/R) than the previous Precision 6262 setup and has better response.


i am not happy that i can't run less than 15psi. i am going to see if i can do anything about it.

[88turboii]

thats disappointing. do you have any pics of the wastegate ports? how big are they?

[RICE RACING]

meh............. while I understand the frustration, 15psi is like the lowest boost ever anyway? you run that in 1st gear, then 20psi second, 30psi 3rd, 45psi onwards in 4th and back down to 30psi in 5th so you don't break the gearbox.

I am different though, 15psi is very low power setting regardless of porting type.

[speedjunkie]

15psi by 3300rpm...Good info. Glad to see the larger frame still responds well with a short runner manifold.

[jacobcartmill]

hey guys, i did a little more tinkering and decided to swap out the wastegate actuators, swapping back to the "medium boost" actuator, and the overboost problem is completely fixed.

i have no idea why the problem existed with only the low boost actuator, but swapping it out completely fixed the problem.

and sorry, i've been on an emotional rollercoaster over this the last 2 days



so i dyno tuned today, and the short story is that this turbo is awesome. running the same boost as my previous 6262 setup, it made 12psi 1500rpms sooner, and made the exact same power. here are the graphs below (scales are different, and different software, but you can see the difference in response)

so the result was 338whp @ 12psi with very good boost response. enjoy the pics and videos.






previous 6262 setup


previous 6262 setup boost response



new EFR 8374 setup


new EFR 8374 setup with power and boost plot (notice the boost is in ~1500 rpms SOONER)


hot exhaust




RX7 dyno, EFR 8374 IWG turbo, 338whp@12psi - YouTube

RX7 BW IWG EFR8374 dyno hot exhaust - YouTube

RX7 BW IWG EFR8374 In Car 2 of 2 - YouTube

[88turboii]

the EFR made 30-40 less hp than the precision almost everywhere else than peak

[jacobcartmill]

Originally Posted by 88turboii

the EFR made 30-40 less hp than the precision almost everywhere else than peak

edit: i think you were looking at the wrong axis.

[FerociousP]

Originally Posted by 88turboii

the EFR made 30-40 less hp than the precision almost everywhere else than peak

3500rpm = 180hp/260tq on the 8374 > 110hp/170tq on the 6262

5640rpm = 300hp/280tq on the 8374 > 280hp/265tq on the 6262

did you mean to say more?

[RICE RACING]

How many milliseconds do you have in your map in vacum to get it to throw flames like that? are you retarding the spark as well or just dumping in a shit load of fuel on heavy decel?

Looks good, all rotaries need to throw flames like that !

[RICE RACING]

................................................

[grantrx4]

That bumper is going to melt! Awesome

[88turboii]

Originally Posted by jacobcartmill

edit: i think you were looking at the wrong axis.

oh snap my bad, awesome results. very interesting

[jacobcartmill]

Originally Posted by RICE RACING

How many milliseconds do you have in your map in vacum to get it to throw flames like that? are you retarding the spark as well or just dumping in a shit load of fuel on heavy decel?

Looks good, all rotaries need to throw flames like that !

RICE, i am using the deceleration fuel-cut with a "fuel restore" value of 10% (which is a little too much) when going from decel to back on the throttle. there is also an ignition retard setting to go with this, which i think is at -5* retard (i will have to look again).

the fuel "restore" should probably be closer to 2-3%, but it's just so damn cool, and it may help to cool off the exhaust slightly (any input on this? i have heard this can have a slight cooling effect on the exhaust).

[PSI]

Great result! IWG is so much easier! What is the IWG area vs the original external WG area? Looking at how much earlier and how sharply power falls over with the EFR you'd have to assume something is choking?
It would be interesting to see what the compressor could do at 22psi where it's right in it's efficiency range.

[Turblown]

Probably too rich and not enough advance up top based on video. The turbine wheel and a/r are even bigger than the PTE. We have many to Dyno including one to 30 psi in a few weeks..