Would the new EFR 8370 be a good match for stock port REW?
Back when the EFR came out they were saying the same or worse then about a Garrett GTX3076, but fast boost response results were just as possible with it too. Which resulted in zoom-zoom-boom when not accounted for properly, the same as is being pointed out here. Not saying they’d be identical due to the ceramic impeller difference, just that the claim in itself lacks context here.
but looking forward to seeing some results.
.
the boring dyno video, believe he upgraded to the 8374 long since then.
https://www.instagram.com/mazdasoforangecounty/
.
and I did forget about this one 7670 0.92 thread from way back in the early EFR days, the highest 7670 result I can recall, but pretty sure it’s either E85 or race gas
https://www.rx7club.com/time-slips-d...-fc3s-1090723/
.
but looking forward to seeing some results.
.
the boring dyno video, believe he upgraded to the 8374 long since then.
https://www.instagram.com/mazdasoforangecounty/
.
and I did forget about this one 7670 0.92 thread from way back in the early EFR days, the highest 7670 result I can recall, but pretty sure it’s either E85 or race gas
https://www.rx7club.com/time-slips-d...-fc3s-1090723/
.
Last edited by TeamRX8; Nov 24, 2023 at 04:07 PM.
Joined: Aug 2004
Posts: 4,772
Likes: 144
From: Colorado Springs, CO
Going by butt dyno I understand what you are saying. You never dynoed your car, right?
We feel the torque drop off in the higher rpms with EFR 7670 and feel torque surge up again when you shift (weird feeling for a rotary).
To some degree I guess it depends on the rest of your engine/peripherals set-up and how high you set the rev limiter over stock redline.
My EFR 7670 maintained horsepower past FC's 7,000rpm redline to the 8,000rpm rev limit even as boost dropped from a peak of 26psi (4,000rpm) to 21psi (6,500rpm to 8,000rpm).
Boost dropped because of high priority dual 44mm external wastegates being pushed further open by exhaust flow at all boost pressures I tried. Would have had to run top WG ports to hold boost.
And here is a half bridge internal wastegate EFR 7670 at 13psi on E85
But I understand wanting to retain the rotary feel of horsepower INCREASING all the way to redline.
So, my next EFR set-up for my FD is going to be IWG 8374 on short manifold with low boost (plus boost creep) with big ports and 9,000rpm rev limit.
Torque at wheels from 5.8:1 differential ratio instead of high boost.
I will probably have to put a plenum on the LIM to shorten the runners and pitch the HP toward the high rpms.
We feel the torque drop off in the higher rpms with EFR 7670 and feel torque surge up again when you shift (weird feeling for a rotary).
To some degree I guess it depends on the rest of your engine/peripherals set-up and how high you set the rev limiter over stock redline.
My EFR 7670 maintained horsepower past FC's 7,000rpm redline to the 8,000rpm rev limit even as boost dropped from a peak of 26psi (4,000rpm) to 21psi (6,500rpm to 8,000rpm).
Boost dropped because of high priority dual 44mm external wastegates being pushed further open by exhaust flow at all boost pressures I tried. Would have had to run top WG ports to hold boost.
And here is a half bridge internal wastegate EFR 7670 at 13psi on E85
But I understand wanting to retain the rotary feel of horsepower INCREASING all the way to redline.
So, my next EFR set-up for my FD is going to be IWG 8374 on short manifold with low boost (plus boost creep) with big ports and 9,000rpm rev limit.
Torque at wheels from 5.8:1 differential ratio instead of high boost.
I will probably have to put a plenum on the LIM to shorten the runners and pitch the HP toward the high rpms.
Then when the oil seals failed, I swapped to the IWG 8374. I'm using the Turblown cast short runner manifold now, and I changed to a 3.5" downpipe on this one to assist with spool. The rest of the exhaust is still 3", at least for now. I've thought about doing 3.5" on the rest too. Everything else stayed the same though. I took the car to Porsche of Colorado Springs in 2016 after I swapped because I had a lean spot from 3500-4000. That was the only place that had someone that had ever tuned Syvecs but he'd never tuned a rotary, so he was very conservative and still didn't fully take care of the dead spot. I never got any documentation from that one either though.
I found the opening in the end tank because I saw an oil mess on the engine only in a certain place and traced it back to that opening, and also realized my oil seals were bad.
Last edited by speedjunkie; Nov 24, 2023 at 04:32 PM.
Joined: Aug 2004
Posts: 4,772
Likes: 144
From: Colorado Springs, CO
Lucky 7 racing has one installed on a street port pump gas FD build. We should get real world results soon including 7670 comparison from the same dyno. Supposedly ready to dyno this week: https://www.instagram.com/p/Cz4h6hCO...RlODBiNWFlZA==
I’m buying sensors and such to instrument the install on mine. Shaft speed, egts, and emap. I’ve got just enough inputs left on the Adaptronic for those.
I’m buying sensors and such to instrument the install on mine. Shaft speed, egts, and emap. I’ve got just enough inputs left on the Adaptronic for those.
and I did forget about this one 7670 0.92 thread from way back in the early EFR days, the highest 7670 result I can recall, but pretty sure it’s either E85 or race gas
https://www.rx7club.com/time-slips-d...-fc3s-1090723/
.
https://www.rx7club.com/time-slips-d...-fc3s-1090723/
.
Joined: Mar 2001
Posts: 31,796
Likes: 3,210
From: https://www2.mazda.com/en/100th/
obviously less backpressure is better, it raises the PR on the turbine side. on the turbine side more PR is better
A note so people arent afraid if EFR reliabilty-
Speedjunkie's EFR 7670 oil seal failure was due to (instrmented) turbo overspeed while running with the boost leak. It is a testament to BW quality control the fragile TiAl exhaust wheel didnt come apart 1st.
Oil seal wear from turbo overspeed is an issue common to all turbos.
Speedjunkie's EFR 7670 oil seal failure was due to (instrmented) turbo overspeed while running with the boost leak. It is a testament to BW quality control the fragile TiAl exhaust wheel didnt come apart 1st.
Oil seal wear from turbo overspeed is an issue common to all turbos.
that’s maybe why they haven’t released a larger A/R turbine for it though … and also why the still in waiting EFR7163 I have with a hybrid 1.25A/R turbine has a speed sensor on it. A smaller diameter is better in that regard too and may have contributed as well.
.
.
Last edited by TeamRX8; Nov 25, 2023 at 04:34 PM.
Joined: Aug 2004
Posts: 4,772
Likes: 144
From: Colorado Springs, CO
i made a little pressure fitting and checked post turbo pressure with an old boost gauge. i mention it because i went 94mm exhaust and noise is a thing. its not so much the Db, but its more like the pitch dropped so you feel it more.
obviously less backpressure is better, it raises the PR on the turbine side. on the turbine side more PR is better
obviously less backpressure is better, it raises the PR on the turbine side. on the turbine side more PR is better
A note so people arent afraid if EFR reliabilty-
Speedjunkie's EFR 7670 oil seal failure was due to (instrmented) turbo overspeed while running with the boost leak. It is a testament to BW quality control the fragile TiAl exhaust wheel didnt come apart 1st.
Oil seal wear from turbo overspeed is an issue common to all turbos.
Speedjunkie's EFR 7670 oil seal failure was due to (instrmented) turbo overspeed while running with the boost leak. It is a testament to BW quality control the fragile TiAl exhaust wheel didnt come apart 1st.
Oil seal wear from turbo overspeed is an issue common to all turbos.
Just to add some information on this. I've got an IWG 8370 ready to go onto my stock port FD. The motor is a Mazda crate engine with no internal modifications, a 3 inch exhaust, Xcessive LIM, and DBW on the stock UIM. My power goals were at least 400 at the ground with as much low end grunt as the tires will hold. Once I get it dyno'd I can add the findings here.
Just to add some information on this. I've got an IWG 8370 ready to go onto my stock port FD. The motor is a Mazda crate engine with no internal modifications, a 3 inch exhaust, Xcessive LIM, and DBW on the stock UIM. My power goals were at least 400 at the ground with as much low end grunt as the tires will hold. Once I get it dyno'd I can add the findings here.
Lol no worries..I'm almost wishing I went EWG to get the larger A/R but we will see how it does. If nothing else, I'm helping to establish the knowledge base for this setup.if I fall short of my power goals, I may move up to the next larger turbo.
Did you ever get it tuned on pump? Would appreciate your learnings if available.
Just to add some information on this. I've got an IWG 8370 ready to go onto my stock port FD. The motor is a Mazda crate engine with no internal modifications, a 3 inch exhaust, Xcessive LIM, and DBW on the stock UIM. My power goals were at least 400 at the ground with as much low end grunt as the tires will hold. Once I get it dyno'd I can add the findings here.
Joined: Aug 2004
Posts: 4,772
Likes: 144
From: Colorado Springs, CO
Thread
Thread Starter
Forum
Replies
Last Post
Matty's first 1st Gen
1st Generation Specific (1979-1985)
15
Mar 28, 2006 05:12 PM
nocab72
3rd Generation Specific (1993-2002)
6
Oct 24, 2002 09:06 PM