Going single...need some advice on a setup
 

We're still not 100% sure but I think I have a bad coolant seal which means it's time for a rebuild. While the engine is out (and it needs to be retuned anyway) it's a great time to go single and do things right.

I'm aiming for no more than 450whp but want a turbo that can support about 500. Reason being is that I know power is addictive and if I start with 400 I'll end up going higher later and I'd hate to completely replace the setup later. So a LITTLE headroom is desired. Steve Kan will be tuning the car and likely doing the rebuild. I also want this thing to spool like a monster. I have 290whp on stock sequential twins right now and like the spool time. :nod:

Current Mods

• Peter Farrell Supercars SMIC
• ID2000 secondaries and stock primaries
• Apexi PowerFC
• 3" exhaust all the way back
• Rotary Performance high flow fuel pump
• Cooling Stuff (Fluidyne rad, stock dual oil coolers, Pettit AST)
• Street/strip clutch (not sure what kind, it was on the car when I bought it)

When we do the rebuild I'm also planning to do a streetport. So far I'm liking the way the BorgWarner setups look. Having everything contained on the turbo itself seems like a neat idea but I'd like to hear how that works in reality from someone who has been running one for a while.

What should I be looking at and what else will I need to support my desired ~450whp goal?

Bw efr.

That's what I'm looking at right now. The 8374 seems to support the ultimate power level I'm wanting but I'm worried about spool time. The 7670 will spool quicker but their site says the 7670 will only support 400whp on the 13b. Is that true? Seems beefy for only 400...

And thank you mods for moving this thread to the appropriate section. I basically live in the 3rd gen section and didn't realize this single specific section existed. :)

Italyn I am using the 8374 and the car is a rocket! I made 27lbs boost at 3200 rpms... Full TQ at 3600 rpms. When I am on the track and I hit the gas there is no delay pretty much instant spool. Its interesting you don't feel that punch of power of a late spooling car it just goes. I will be retuning the car for 35PSI on september 4th should be fun :). I would go with Turblown full kit as it fits well and produces great power/response!

Here is a video of me rolling racing at the local track in my area... If you are not interested in the IWG check out Mannykiller's build thread his 8374 External WG setup is pretty wicked as well.

^ I actually watched your video earlier today. I saw your mods list at the end but I didn't see how much power you were making. Mind sharing?

PS: Nice save near the end!

I made 486hp 408tq on the first dyno of the year @ 26lbs boost. I had my fuel pump jumper for 1/2 speed so at the top end I was loosing fuel pressure. I wired the pump to my adaptronic 440 Ecu so that at 3lbs boost the pump would go from 1/2 to full. We attempted to redyno the car again but the place I had went to was not able to produce the boost I could on the street for some reason. So in the video I am not sure what my hp is... we assume over 500... So that is why I am going back on the dyno on the 4th to hopefully get an official number.

what fuel are you planning on running? shawnm565 mod list says e85, I would set your goals with the fuel your going to use. I would find out how much power that fuel pump is good to. And remember if you run e85, you need even more fuel to hit that hp. 450whp I would consider changing all the fuel line on the pressure side to -6, and you will probably want bigger primary injectors . Basically I'm saying fuel, fuel, fuel!

Ditto on that!
If you are wanting headroom you'll need to address the fuel supply.

I'm coming to terms with the fact that I'll likely need to upgrade primaries but we'll see. Honestly, I want to run pump gas (93 here in TX) for the most part but dump some race fuel in on occasion. I really can't anything over 93 except at local race tracks. Sure E85 is able to make great power but I drive my RX7 a lot (10k miles last year :) ) and I want to be able to enjoy it without worrying about where my next tank is coming from.

But I may have just answered my own question then. Nearing 450 I'll have to be running more than 93 so maybe the 7670 is a better option? What else is out there that I should be considering? Anything from the GTX line or similar?

An ecu that supports flex fuel allows one to use both fuels(pump gas and e85). 7670 will hard stretched to make 450rwhp.

Turblown, what's the RPM difference in spool for the 7670 and the 8374? Is it a huge difference?

If you want something in the 450-500 range, the efr7670 is probably too small a turbo. The EFR8374 is what you want.

^That's what I'm thinking.

Also, since we're on the topic of e85 and flex fuel ECUs. What all needs to be replaced with regards to fuel lines and such to ensure it doesn't rot out? I know the older fuel systems weren't built for it.

the 7670 is not appropriate for your 450/500 power objective.

7670

at 14.7 psi boost max (rotary rw) power 354
at 20 psi 392
at max output (41 psi) 471

8374

at 14.7 psi 459
at 20 psi 527
at 40 psi 580

the 7670 is a small (but very efficient and well designed) turbo

compressor wheel has 5.5 sq inches average area, compares to GT35 at 6.38...

the 8374 has a 6.6 sq inch compressor and is a mid range power turbo.

given your objective of 500 hp you are looking for a mid size turbo.

two other options (both BW) are the

S300 63 (P/N 177283) inexpensive, excellent with a rotary friendly hotside

S300 64 FMW same size but w a stronger more efficient billet compressor wheel and upgraded bearing assembly, slightly more $ but significantly less exp than the 8374

as to spool... there are a million factors BESIDES the turbo that influence spool significantly. i find FD owners that are contemplating going single worry about losing midrange power. a properly engineered single makes so much midrange power that your primary concern will be finding any traction in the midrange.

for instance, my 2013 setup w a larger GT4094r (8.1 sq inch compressor) made over 400 SAE rwhp at 5000 rpm! a great deal of the reason for good midrange relates to factors other than the turbo.

my recommendation to you is if you have the $ go for the EFR 8374 as it is a clean sheet of paper high performance turbo. if you are more budget minded either of the other turbos will make you a very happy camper.

good luck,

howard

Wow, thank you for the extremely detailed response Howard. I've read a number of your posts and you definitely take a lot of time to give a proper explanation.

I'm aware that spool is related to a lot of things but I think there are still a few generalizations we can make when comparing two turbos on a similar/equal setup. I'm just trying to get an idea of what midrange power band I'd be giving up by going with a larger setup. But I agree with you, my current stock twins are already enough to render first gear useless even with 275s on the rear. :D

I'm not opposed to the idea of the 8374 (in fact I think it's in the lead right now for me). I'm very interested in the flex fuel ECUs though. Does that change the tune on the fly depending on what's in the tank? Meaning, I roll up to the gas station with an almost empty tank of 93 and the engine has been making let's say 350whp and then I fill it up with E85. Is the ECU smart enough to up the boost and change the map such that when I drive away it starts making 400+ or whatever the E85 tune is?

I will have some data by end of this year beginning of next year. I will be tuning or at the minimum riding in the following cars that are all local here to COS (6300FT above sea level).

I own a GT3574R, I am tuning very soon a GT3574, One guy is running a S300? or S360. Speedjunkie runs the EFR 7670, Jason is swapping to a EFR 8374. We have all the turbo's you are contemplating....the only thing is we need to tune all these cars and get everything installed which is happening right now.

My GT3574R spools fine, has power everywhere, and does great. I can cruise without much boost, get good MPG, and its got good midrange power and top end.

the EFR7670 is a low end to mid range powerhouse, spools like a beast, runs balls out fast, might give a little up top but man does it get there fast for an awesome street car. The downside is you are boosting some in low rpms when cruising, eats a little more fuel, but you can boost like made cruising in 5th gear to pass someone.

I will get you more info on the others as I ride or tune them.

I don't think any ecu will recognize a fuel without you telling it even though it has a small learning curve. You would have a completely different map for the 2 fuels.

LOOKatme i have a question, at what rpm does the 7670 runout of steam 7K ? And also the 8374 thanks

Running out of steam is based off of many variables.

I don't think anyone on this forum has dyno tuned a 7670( if so no one is sharing so far).

In theory it should start fading around 6500rpms just like the GT35R.

It should also " spool " around 400rpms faster than the 8374.

We have sent a ton more 8374 kits out and I know of at least 3 that are very close to be tuned. We've got one more engine build to finish and I will be tuning a 7670 to 20+psi on E85. I've attached a picture of another 8374 kit that is being I will be tuning by the end of next month if all goes to plan...

We are also wrapping up another 7670 IWG kit( and 2 EWG kits also).

In addition we are delivering a few more 9180 EWG kits too...

I intend to do back to back dyno tests this winter with our latest shop car addition for both IWG VS EWG, long vs short runner and 7670 vs 8374 vs 9180, low and high boost etc...

Thanks for the reply turblown! Ill keep an eye out for your thread, cant wait to see what you guys find

Agreed! Can't wait to see some comparison results! :nod:

Just drove the EFR 7670 in my FC the first time today, should get it tuned this week- though it will be lower Dyno Dynamics #s.

I might be able to get Dynojet #s on the 6th when a dyno rolls into town for the diesel guys.

I am running ~12psi now off wastegates and it hits full boost ~2,600rpm rolling on in 5th.

Its like 1-2psi @ 1,500rpm, 3-4psi @ 2,000rpm, 8psi @ 2,250rpm with a little wastegate noise and 12psi @ 2,600rpm.

Might get better with tuning as I wasn't seeing as much boost below 3,000rpm with my old turbo.

Its not as snappy as my FDs stock sequential twins, but its really good for a single turbo.

It feels like it will be a solid 350rwhp turbo on the rotary with the *possibility* of stretching it to 400rwhp.

Basically the same as stock twins, with more simplicity, less power 1,000-2,000rpm and the ability to run higher boost (but not really make more power so what does that matter really?).

and the ability to run higher boost (but not really make more power so what does that matter really?)

Actually, running higher boost should yield more low end to midrange power than the twins can muster- so it might be good for something. We shall see.

Great photos BLUE TII and thx for the info, keep us updated!

If you are using s4 t2 rotors it will not be as responsive as an engine with s5/6 rotors.

I don't have HARD data. this is all from personal opinion and from my experience at 6,300ft above sea level which effects spool times and what not.

Speedjunkies car is set up for spooling the turbo quickly outside of his monster exhaust ports which lead to his engine going out shortly due to damaged apex seals (from the ports). He has a short runner manifold and the turbo sits low next to the engine with dual external wastegates. He has a smaller sized V-mount intercooler with 2.5" piping, fitted with a larger filter on the intake right next to the V-mount. He runs water/meth and ran his turbo at 24-25PSI. His engine was spooling in the 2000's rpms and if he gets into it, he can spin the tires loose in the mid 3000rpms in 2nd gear from what I remember. His car pulled hard to redline, but the acceleration would lighten a little around low to mid 6000's rpms. It's not like a brick wall or anything like that, it just doesn't pull like my GT3574R does up there. mine comes on less harsh down low and slowly builds all the way to redline.

Whichever turbo set up you decide on just shifts power up and down based off the size of the turbo since most of the technology is the same except for maybe the EFR's lighter hot side which helps spool the turbo up.

Also, tuning makes a difference and people need to decide what they want from the car. I choose to have a little less spool down low with a tune that is leaner in the cruise cells for better mileage when doing long cruises. Others want more performance and worry less about MPG, run richer AFR's down low (say 13.5) in cruise cells and spool is much better at this AFR which drives more exhaust gases to spool the turbo. Speedjunkie had a lot more aggressive tune AFR wise than mine and spools like a beast. The downside is his turbo spools a ton cruising around going up and down the hills here and on the highway that he eats through his water/meth tank pretty quick. That is how much this turbo spools in the lower 2-4K rpm range.

In the end I like my turbo and I like his. Mine is great for hitting the mountain roads up here when the air gets super thin and the roads are wide open and fast. His is amazing for a street car and I love how you can catch a gear higher and drive through the corners....its smooth and the car responds so well, so quickly. I think both turbo's EFR7670 and EFR8374 would be great to run. I will be in a 8374 soon and see how it performs. I guess it all depends on what you want out of the car. Sometimes I personally wish I had a 7670, other times I am content on what I have cause I can cruise without boosting much, then bam hit it when I want to. On the other hand, coming around a slow corner and in 2nd gear in the EFR7670, you can just LEAP out of the corner like a boss going 15-20MPH, and if wanted lay a damn patch of tire marks just blipping the throttle down without clutching it.


Keep in mind that we are at altitude, those closer to sea level will probably be better off with a larger EFR8374.

Porting has the biggest affect on response and where the powerband is. Stock vs large ports generally shifts the response up to 1000rpms.

his rebuild will have stock ports.

Isn't there porting that helps spool? Sean at aspec said in a thread that opening up the exhaust a little bit can help increase spool. I think that's what he said, I wish I could find it now.

The short answer to that is yes, but it can be somewhat complicated.

Most porting is done to help peak HP. This is not particularly conducive to helping spool.

If, however you work the porting with the strategy of increasing spool, then it can definitely help,

Think of porting more like a cam in a 4 stroke piston engine. You can get a cam that has lots of lift and duration for peak HP which isn't very good for a turbo. But if you get a cam designed to work with a turbo you can get the most out of your turbo.

Not sure if you were talking about someone else or not but my rebuild will be a street port rebuild.

Also, I'm leaning towards the GTX35R as my turbo of choice thus far. Been comparing a lot of different ones but I think this one is likely best for my power level and isn't as expensive as the BW turbos.

A gtx3582r with a t4 1.06 housing is more than an 8374 efr http://www.turbosource.com/Borg-Warner-EFR-8374-p/ts1-03-83740.htm.

Isn't there porting that helps spool? Sean at aspec said in a thread that opening up the exhaust a little bit can help increase spool. I think that's what he said, I wish I could find it now.

Yes, opening the intake port earlier for more overlap (air and fuel into the exhaust) and opening the exhaust earlier (increases manifold burn) both increase turbo spool.

For instance the Alpha 4C production car uses "reverse V-tec" where it is on a high overlap cam down low for spooling the turbo and then switches to a low overlap turbo cam up top to keep from losing its boost out the exhaust for more turbo power on boost.

Granted, its easy to screw this up as any increase in runner volumes is going to lose you low end power from lower velocity.

Late closing intake and exhaust and huge ports is what kills low end power in the rotary.

i've had several single turbo setups over the years, and the EFR 8374 turbo (internal wastegate) setup is by far the best one possible for what i'm doing.

^more on what *i'm* doing:
my car is a weekend/track car running low boost (~11-12psi) and making ~350whp (it was 338whp on a dyno dynamics, ~380whp dynojet). it would easily do over 400 with the boost raised a few psi.

the car has seen 5 track days and i have absolutely flogged it at all 5 events. i've been to 3 track days with this turbo setup, including one in 95*F+ 45% humidity weather in alabama and the turbo and internal wastegate have had no issues. these track days are over 100miles on track and ~2 hours of tracking.

i am using a turblown shorty (IWG) manifold and i made all the hard lines and have a custom downpipe and oil feed and drain. (it's similar to the full turblown kit). i'm also doing some changes to make a cold air intake and new intercooler setup, which you can check out in my build thread if you're interested.

i would much rather have this turbo setup than a GTX35R, and i'd recommend getting the internal wastegate due to its simplicity and reliability, unless you really like the chainsaw 2-rotor wastegate vent sound, which i find horrifying (and don't even think about plumbing both wastegates back into the downpipe).


also, i saw a post on the previous page of you mentioning *first gear being useless*. isn't first gear useless in a stock FD at 10psi? maybe you haven't driven a 400whp FD. you can easily spin 3rd if you're coming out of any kind of turn, and almost spin 3rd in a straight line. of course this is dependent on your tires, and you'll spin 5th if you're running on plastic 165s.

Basically the same as stock twins, with more simplicity, less power 1,000-2,000rpm and the ability to run higher boost (but not really make more power so what does that matter really?).


Actually, running higher boost should yield more low end to midrange power than the twins can muster- so it might be good for something. We shall see.

Well, I melted a dyno strap so I didn't get my full tune yet, but I will say that the EFR 7670 will be THE monster midrange turbo.

I did make 369 FT/Lbs at 3,200rpm @ 28psi boost.

As predicted the full pulls we did on low boost levels were pretty low HP. 275rwhp on 11psi wastegate and 308rwhp on 14psi. It feels even slower than that driving as power never "comes on".

We will try to get full high boost pulls this weekend. It looks like it will make great low/midrange torque and then take a dump between 5-6,000rpm.

Why is that..? because its just fiddly to do, or other reasons?

Same results as speedjunkies. Massive power in that 3000's rpm. It is a complete midrange turbo and spools like a beast giving up some top end.

HP at 28psi ?

That is good to know you are having good results with that turbo. I was afraid rotaries would have issues with the internal wastegate not being big enough. No boost spikes or anything?

I have a hookup on garrett turbos. I'm wondering if any of the garrett internal wastegates would also work on a rotary. I don't even think they offer an internal wastegate for a gt35r with a t4 exhaust flange

Keep in mind that comparing peak hp is not apples to apples.

An efr or any small to medium frame turbo run at high boost will make a ton of torque but relatively low peak hp.

I built a stock twin turbo car that made 289rwtq/300rwhp and it ran 11.9 in the quater. It also beat a single turbo fd making 350rwhp.

Peak hp does not necessarily indicate how fast a car is.

Just look at how fast the efr roll racing video car is. It only makes around 500rwhp.

HP at 28psi ?

369ft/lbs at 3,200rpm = 240rwhp at 3,200rpm

3,200rpm is where we stopped the pulls as the car was climbing the rollers badly (due to the burnt/broken strap as we discovered). Have I mentioned how much I hate roller dynos?

The EFR 7670 flows 64lbs/min peak- I would imagine that will be ~366rwhp on this dyno/engine as my 60-1 HiFi (~57lbs/min) maxed out at 334rwhp.

I am hoping to get on a dynojet on the 7th where it should just touch 400rwp *if* we are able to get ~360rwhp out of it on the dyno dynamics.

I feel this turbo is likely to make more torque than hp as torque will drop before 5,200rpm.

The car IS fast, but no longer drives like a rotary- I am not sure how I feel about that. I will decide after I auto-x race it some.

Does your turbo manifold allow enough clearance for the bigger 8374, or is it placed like this;

FD3S Short Runner Manifold

If all goes to plan we are tuning an 8374 on the 4th to as high as the turbo will go...

As a base manifold I used an old HKS SS tubular. It is what was in the HKS T04Z kits before they went to V-band flanges.

Attachment 639011

Yes, it appears the 8374 and 9180 will clear in the FC with this manifold.

At most I would have to grind a flat spot on the front lower intake manifold runner where the compressor cover v-band is.

it's quite complex (and thus expensive) and i could never get my vband connections to seal perfectly. it also made the removal of the downpipe (in general) much more difficult. i can now remove my IWG style simple downpipe in 5 minutes (no joke).

i have no boost spikes. i did have some issues at first with possibly having the wrong actuator, but now i've switched to the "medium boost" actuator and the boost shoots straight to 11-12psi. it did bleed off slightly (~2psi) by redline, but i'm using my haltech electronic boost control (and the EFR included boost control solenoid) to control the boost. i simply made a slight increase in the wastegate duty for the higher RPMs and the boost is totally solid right between 11-12psi.

here is a pic of the dyno (the dyno was reading about 1psi higher than my Haltech FWIW):

https://www.rx7club.com/attachments/...g-me-dyno6-jpg

here's a graph with the axes matching:
https://fbcdn-sphotos-g-a.akamaihd.n...50843906_n.jpg


here's more info (and a link to the post # in my thread) with more info comparing my EFR turbo to my previous Precision 6262 external-dual-wastegate setup:
(watch the videos to get an idea of the responsiveness). i can't imagine why you'd need the boost any more responsive than this 8374 .92 setup is.
https://www.rx7club.com/build-thread.../#post11704677

Great fd
 

That's your user name so I can add you to my YouTube channel

Both
 

You would need to open up both intake and exhaust ports
I would suggest going
street port!
That's what I'll be doing over the winter..
Now reading this am thinking of going with The 8374
The plan was gt35r but not to sure now..

8374 is a superior tubro in terms of spool and response, the GT35R is not a bad turbo (I have it on my car) but the lightweight hot side and little better exhaust to compressor wheel ratio on the BW EFR makes it better.

thanks for the info... but with the gt35r i would need an external waste gate too

the GT35 and the EFR 8374 are very different turbos.

the GT35 is a small turbo.

the EFR 8374 is a middle size turbo

GT35

compressor size 6.38 average square inches area/ cast

turbine size is 5.17

EFR 8374

compressor size 6.62/ Billet

turbine 6.23......... plus 20.5% to the GT35

assuming both turbos can be driven to the 60% edge of their compressor maps...

at 14.7 psi boost

GT35 max power 420

EFR 8374 max power 460

at 20 psi

GT35 440

EFR 8374 527

EFR at 40 psi boost 580

one of the significant benefits of the EFR is the larger hotside turbine wheel. the more efficient the hotside is the lower the EGT which pays dividends both in and out of boost. less chance of warped apex seals.

the GT35 is a nice turbo but IMO the primary drawback is the smallish (80% of the cold side) hotside. since our motors require 30% more flow to make similar power to a piston engine and the exhaust is generally around 2-300 degrees hotter big hotsides work really well.

Borg Warner generally offers better hotside options. the garden variety BW equivalent to the GT35 has a 6.31 inch turbine. plus 22% to the GT35. OE build quality.

you won't go wrong w any of the aforementioned turbos but it will be important to pick a turbo that properly fits your objectives.

howard