Edit- Confirmed NOT on shootout mode

KNONFS

Hey man, do you have a comparable dyno of your setup? I am probably wrong, but I thought your setup was not able to maintain boost up top.

You are exactly right.
Even on low boost setting my 7670 boost dropped in the higher rpms, which I have attributed to exhaust manifold pressure pushing my high priority wastegates open. I never printed the low boost EFR runs.

If I put the 7670 set-up on the FD I would try dual port wastegate set-up to keep them under control.

7670 was 270rwhp DD with boost set to pump gas setting of 12psi and dropping to 8 or 9psi.
My 60-1 did 295rhwp DD on 10psi creeping to 11psi which also dynoed at 343rwhp Dynojet and 345rwhp Dynapack.

This DD consistently dynoed 16% lower than Dynojet, so the EFR 7670 was 313rwhp Dynojet at 8psi or 9psi on my pump gas setting.

Remember we are talking about PEAK hp (and boost).
I was perfectly happy on the pump gas tune to lose 25-30hp peak and gain much more under the curve and gain power everywhere on race gas tune.

James2u

EFR 7670 IWG dyno result, car is a 94 FD built for autocross. The car was tuned for high boost with 110 race gas. Boost at 17psi, it bled to 15 psi at high RPM.

-Turblown EFR 7670 IWG kit with 3" downpipe, new cast shorty turbo manifold

Beast! I am loving it.

That is animal power levels.

You are missing a lot of response down low when using the OEM medium canister with no controller. The OEM BW actuator cracks at 11.2 psi, so the response from 11 to 17 psi is going to be sluggish with no controller( assuming you guys did 3 turns of preload). Even at 7 turns of preload it will still crack at 14psi.

This also explains the higher rpm boost fade to 15psi( no controller).

See the chart in our blog;

BorgWarner EFR Installation Guide | TurboSource

So if one wants 17 psi, the controller should be used, or move to a turbosmart actuator with a 17psi spring.

Again you might start fighting wheel spin even at your current power levels so it might not be necessary at all.
TurboSmart Dual Port EFR IWG Actuator Upgrade

Did you look at the same graph I looked at? :scratch: Stock twins maxed out would never make 300 ftlbs at 3k rpms even sequentially. James2U dyno graph is the most impressive Ive ever seen on a 2 rotor for power/torque where it matters on a 400hp setup.

Uhhh....

What are you talking about? The curve may look like a similar shape, but the amount of power is double. Stock twins cannot make this power for long at all, and I don't they really make this much power ever as they are no longer efficient,

edited because forum not letting me link pics from itself? Will try again later.

Impressive, if optimistic.

I'm looking not at a particular peak torque rate at whatever RPM. If someone want to have high torque at minimal RPM, I would recommend to get you a Diesel, not a rotary.

My statement is related to the power you can make on particular turbo. Money and power vise, it dos not make any sense for me to exchange stock twins against this little turbo.

Best ,
Iwan

Iwan
I'm looking not at a particular peak torque rate at whatever RPM. If someone want to have high torque at minimal RPM, I would recommend to get you a Diesel, not a rotary.

My statement is related to the power you can make on particular turbo. Money and power vise, it dos not make any sense for me to exchange stock twins against this little turbo.

Best ,
Iwan

I'm not trying to talk you out of stock twins, I have those on my FD and I like them and the lower racing class I get to be in because of them.

My 7670 was on my FC.

The EFR 7670 is pretty nice as a single at the same boost the stock twins can do because it doesn't sacrifice response for the simplicity of a single upgrade and can make a little more power under the curve as well as peak power.

But, for low boost on the street, I think the EFR 8374 is the way to go. Nearly stock twin response and way more power than stock twins at the same boost.

At high boost when racing like I used the EFR 7670 for the stock twins can't come close to comparing.

You have never seen stock twins come even close to this kind of power.

Why would you want torque to go with your horsepower in racing?

So you get the same pull at any rpm in any gear as you do at peak power on the stock twins.

Example: When I plotted torque at the wheels for my EFR 7670 FC it make the same torque at the contact patch at 100mph in 3rd gear, 4th gear and 5th gear.

That means that this 420rwhp turbo pulls as hard at 100mph in 5th as it does at the top of 3rd gear...

https://cimg9.ibsrv.net/gimg/www.rx7...ddaa7966b3.jpg

https://cimg4.ibsrv.net/gimg/www.rx7...57a4df5f56.jpg

Except:

Stock twins will never reliably make this power.
Stock twins will have to be ran non sequential with all sorts of work to get close, and then will spool slower.
Stock twins are still a mass of weight and heat retention
Stock twins still have the entire rats nest to content with


This is a single turbo that gives response like sequential twins with longevity. So it all depends on goals.

If you want 500hp, not your turbo.
If you want more than stock twins but don't want to sacrifice response, this maybe the right turbo.

Also, take into account that this turbo has very well designed separate internal waste gates, built in blow off valve, and a solenoid for boost control.

The value goes up when you consider the simplicity of the install and the new simplicity of the entire system.

I say this because your blanket response is not very qualified. Many just want simple and more power than stock.

My sequential twins makes 250rwtq at 3500rpm, looks like the 7670 can do it at 2900rpm, so I don't know if they are really equal.

A lot of times I agree to having a difference of opinion. In this situation you are frankly wrong. This turbo will destroy the stock twins in peak torque, peak HP, torque under the curve, power under the curve, response, engine bay temps. Unless you want a near stock FD there is zero other reason to justify the twins over this setup. Its unfortunate the EFRs have just been out the last couple of years when the FD is no longer a mainstream option for auto enthusiasts. Those of us still messing with FDs realize how incredible the EFR development has been for this chassis and engine.

And the 7670 is still climbing where as the sequential twins hover until 4500 rpms and still dont compare at that RPM either.

The 7670 is making good numbers but it's being abused to do so. With the responsiveness of the 8374 being similar, I see no reason to run the 7670 and ask it to run outside of its efficiency range. The 8374 will do everything the 7670 will, and more, and be happier doing it.

If this car had the supporting components to hold steady boost, the results would have been even more impressive.

Well, the time will teach us. Have seen lots of cars aged 20 years plus with twins still running even on boost other than stock. BW will need to prove that with time, so nothing about reliability please.

I clearly disagree. I have made 400HP + on stock twins running sequential ....

For the money you need to spend on a single turbo to get maybe 20HP plus, I would simply keep the mass inside and be happy with $3K+ in my pockets

a well maintained car has no issues with rats nest IMHO. If someone have problems with it, simply shows how well someone is looking after his or her car.

Fully agree on that. All depends on what you try to get by the end of the day. If someone want more power without putting stress to the engine by running higher boost, the are many alternatives out there to reach that goal.

Best,
Iwan

Iwan
I clearly disagree. I have made 400HP + on stock twins running sequential ....

Yes and you claimed to make 500hp on a GT35R at 17psi and the dyno graph you posted showed less than 348RWHP (less than 260 KW) and a calculated 507 FLYWHEEL HP (372.5KW flywheel).

I understand that you are measuring with a different dyno.
People only understand/compare Dynojet #s.

My EFR 7670 did 369RWHP on a Dyno Dynamics I parked it in the garage and next weekend drove it to a Dynojet and put down that 420RWHP.

So did mine make 369RWHP or 420RWHP. The answer is "yes".

So, did your stock sequential twins put down 400hp on a Dynojet?

For the money you need to spend on a single turbo to get maybe 20HP plus, I would simply keep the mass inside and be happy with $3K+ in my pockets

Yes, only 20hp more than 400RWHP stock twins at peak power rpm.

But look- 100hp more at 4,000rpm and still 100hp more at 4,500rpm.

I love sequential twins, but the stock ones just can't boost high and make the midrange torque.

I think the obvious answer is sequential EFR twins!

Here is a really impressive stock sequential dyno chart (well BNR Stage III so GT28s).

The 7670 is able to run more boost 3,000rpm to 5,000rpm (and the same boost 6,500rpm on as my 7670 was) and it really shows by how much more midrange power the 7670 makes.

Like I said 7670 is able to make 100RWHP more at 4,000rpm, 100RWHP more at 4,500rpm and still 100RWHP more at 5,000rpm.


https://cimg5.ibsrv.net/gimg/www.rx7...58f2fa46c8.jpg

Well, what you guys are referring to as US RWHP has been proved time over times as corrected power over here in Europe but also in AUSY.

Generally speaking, if you like to compare dyno figures, you should have two different cars on the same dyno on the same day with same settings of the dyno and ppl. inside the car not cheating the dyno by pulling hand brakes or something like that. Not easy to achieve that over the distance, so there will be always some talks and experience based differences in what someone has achieved in regards to the dyno results.

Should not be a dyno thread here, so I will leave it up to every one else his opinion and conclusion.

We have multiple people who have had the stock twins and went to single turbo upgrades.


The list includes.


Speedjunkie
Myself
Geoff (local)
Jturton
15U


We all had the stock twins at one point and we blew them up at high elevation. All of us had issues with the twins working correctly. They do well at sea level. In order to get any power out of the rotary at altitude you must run a larger turbo that is in good working condition. It must also be properly sized (at least a 62ishMM compressor wheel). I tuned 15U with stock twins and a single turbo as well as Geoff's car. The single turbo's are so much better in all ways. simplier, more power, better power delivery, and 15U's turbo's only lasted 3 months before they gave up at 13PSI at high elevation.

Seems Mazda should just slap one of these on the larger 16x and call it a day.

i've said that for months now, i need to do some plotting ...
but i am thinking two 7670 on a 20b. if not two 8374
can two 8374 do 1200 hp? i guess 1100 would be enough... damn i can't afford to put that power down..


if two rotor i think two 7670 is too big.. what about two 7163.. they are also smaller frame turbos...

this the reason i put seq twins on my fc... to learn the manipulate the system and redesign it with new turbos... can i do a gofundme for this?

Sequential twin EFR 7670 definitely isn't too big on a 2 rotor.

We aren't getting the 7670 to its compressor surge line yet and torque/boost falls on its face at 5,000rpm so bringing a second 7670 online at 4,500rpm like stock would be perfect.

You can't stay out of boost on the 7670 on the freeway, the response is very twitchy and hairtrigger. My gas mileage sucked. I needed a more modern ECU that could keep it in closed loop or 02 trimmed open loop at 10psi boost.

It is twitchier on boost over 3,000rpm than driving a stock sequential twins FD with bolt-ons for spool. The 7670 never shuts up, its always whining away in low vacuum or whooshing into boost.

---------
I thought of the 7163 as well for sequential twins (and even the ex IRL 6758 when they were under $500 used).
The 7163 compressor surge line and efficiency islands are the best for sequential twin duty.

It would be insane, it would impact your vacuum on the freeway even on a flat with cruise control. Could not accelerate at all or climb a gentle rise without generous boost.

Could mix and match turbo sizes a bit too like the Cosmo twins.

glad we're on the same page, now i guess gotta convince the boss to let me build/dyno it here at the shop.

i can hear/feel the stock ht 12s on my fc spool from -10 vacuum to -5. i can hear the spooling all the time... sounds like an old radio without a condenser on the engine circuit ..
team rx8 pointed the efficency islands at lower rpm were like perfect i think...

Stock twin turbo capabilities are laughable when compared to the new EFR line and the BNR twins which have been around for a long time.

I distinctly remember the day a few years ago when I decided to go Balls-Out on my BB '95 car.

I was running stock twins at 13ish psi with all possible supporting mods and got smacked down by an SRT8 charger at highway speeds.

This after my old VR R1 at 500+ rwhp on an A-Spec 500R.

No thanks, the twins just don't move enough air for anyone who has tasted real power in one of these sexy ass cars :D

If you're happy with an honest ~400 crank hp (350rwhp?) at the most, then stick with the stock twins sequential.

Otherwise, upwards and onwards :icon_tup: