Is EFR right for me?
 

I just removed a cheap unknown (ebay or rx7store) turbo kit from my new to me fd. Manifold is trash, turbo unknown, junk synapse wastegate, etc, etc. Have talked back and forth with Glease about options, and done tons of reasearch, almost gone blind reading many posts by turblown, bluetII and coleman over the last few weeks. Got it narrowed down to BW EFR for sure, but dont know which one (7670, 8374, iwg or ewg). This car will be rarely driven, mostly twisties in the mountains. Probably try auto-x, maybe even a VIR track day eventually. 350 or so whp would be good with good quick resonse. Pump gas only. I have fuel system mods, ic and water meth already. All opinions appreciated.

EFR is right for everyone, just can you afford EFR and a good manifold is most people's question.

For sub 400 hp the EFR 7670 is the turbo to go with if you're looking for more than 400 hp the 8374 would be a better fit, Elliot and John both make good manifolds for the EFR, Ihor at IR Performance is now making an EFR manifold and kit as well seeing that you mention VIR

I suppose, but if you look at the "good" gt35 kits they are $3,xxx. Compared to say, turblown's own current EFR gb which *might* reach the mid 3s eventually, it doesn't seem so out of reach.

I thought so too, I like the idea of the response of the 7670, I'm just not sure I'd want to run the higher boost pressures to make those power levels on pump gas?

I vote EFR 8374 for your goals.

^Agreed. Always go a bit larger to give room to grow and so you're not running the turbo out of it's efficiency range.

I'm rocking a Precision 6466 ball bearing unit and love it. It's been bulletproof and isn't even breaking a sweat at 15 psi....... have tuned it as high as 1.35 kg on the PFC commander, so about 20 psi.

The new EFR line seem awesome, if the boost control issues can be sorted with them they seem like the perfect street turbo :icon_tup:

If you only want 350rwhp the 7670 is the way to go. To be clear there 7670 iwg NEVER ever has had a boost creep issue, and will hold low boost regardless of any variables. There is zero reason to run the 7670 in ewg form unless you like the noise.

What if you are right on that ~400whp line? Like you want that low end, but maybe you want to run a high(er) boost tune that nets you around 450 to the wheels at some point?

I know OP said 350 but I feel like there are a lot of people around all of these numbers (350-450), or looking to make at least. Just adding to convo, not really trying to threadjack, so sorry if I detract at all, heh....

I was hoping you would chime in, with your experience with the 7670. Care to elaborate?

Why do you think it is that only the 8374 has creep issues? Just moves too much air for a small internal wastegate? Manifold design aside, cast or a good fabricated one, for someone wanting 15 psi on pump with an 8374, large or dual ewg's are more ideal for this turbo, no?

Very few 8374s will boost creep past 13 psi, I mean 1 in every 100 that I have seen. I already sorted out that porting the 8374 and larger housings will fix any cars with creep. Personally I would just leave it. One can run more than 15 psi on pump, you just have to run it rich(sub 10.5 afr).

aplscrambles

Originally Posted by BLUE TII View Post
I vote EFR 8374 for your goals.
I was hoping you would chime in, with your experience with the 7670. Care to elaborate?

I have found pump gas is only reliable to ~12psi depending on your compression ratio and turbo set-up (larger exhaust housing and 8.5:1CR could run 14psi).

EFR 7670 will need a friendly dyno and a really good engine/turbo/etc set-up to make 350rwhp on 12psi.

EFR 8374 will make 350rwhp at 12psi without much effort.

8374 with ewg 1.05 still spools beautiful. Mine with ebc turned off on 7psi springs has rock-solid boost control and response at 7-8psi, just for a stupid example. May not be able to do that with the IWG. I used the light springs for run-in purposes but they work well and are great in the wet so they stay. EBC has no prob with 18psi. (maybe more? car is tuned to 18)
Went with ewg for packaging concerns more than anything else (tight engine bay/ existing twin gate mani) but glad i did.

EDIT, but if you need new manifold anyway and already have water inj, it would be mad not to consider turblown iwg kit. Those cast manifolds are sexy.

Has anybody compared the spool (using the same porting) between the EWG 8374 and EWG 9174, along with tq/hp curves?

I plan on tying up my (long) rebuild process this fall/winter and I'm on the fence between those two turbos... The spool of the 8374 is very appealing, but I'm also keen on the potential to hit 500whp if needed to squash an exotic's ego..

I've got FULL supporting mods and will be running a Life Racing F88 ECU (motorsports version of the Syvecs S8) so I'm not concerned about a weak link outside of the turbo..

I like the 8374 as what seems as the best all around turbo for the 13b. It has excellent spool and flow. Drive it on the street or track. I would go with the internal gate. It fits without issues with accessories. I also like the 9174 as it fits between the 8374 and 9180 so for those who also street the car but want 500+ it may be the right turbo. I don't think I would consider the 9180 unless it's an all out track car.

I've been seriously considering these turbos also and trying to read everything I can. Looking at dyno sheets for power under the curve for street ability and see who is making that power on stock ports.
I'm leaning towards the 8374. Pump gas and water meth, plan on keeping the stock driveline with just upgrading the clutch. I run an ACT and a aspec GT35R but want more low end and overall a bit more power.
As much as I like the sound of 500+ hp I just don't want to have to go to a different trans or rear. That means I also don't want to be constantly repairing my trans and diff.

18-19 psi on a stock port 13brew is prob as far as I want to take this car. I see a lot of ported motor sheets with these turbos so I can't gauge where that puts the power level for an 8374 for me but I figure around 450-470rwhp.
More than enough for me. Now I just have to wait until tax time next year.

^^^ Agreed.

The 9180 is a little big for my desires (street car with occasional auto-x and rare track time), but I also don't want to *need* to push the turbo to hit that peak power..

As I've become older an "wiser" I realize that I neither need, nor really want, a 500whp+ monster during 95% of my projected use... Truthfully I'll likely want no more than 350-375whp more often than not. HOWEVER, it would also behoove me to have those power levels (looking at a cal switch with 350-370whp, 415-430whp and ~500whp) will less work from the turbo. I figure less work = less heat, and less heat = happier motor.

I've got a decent sized street port (I almost wish I had kept it closer to stock, oh well..) so I'm also interested in the sheets for motors with smaller ports.

I guess it's all a balancing act between response, useable power, heat generated, and physical space required..

It's obviously difficult to forecast the characteristics with a stock port, when all the graphs shared are from larger/bridge/Peri ported motors, as they are apples (stock) to oranges (not-stock), but I guess you *can* estimate some things about apple characteristics if you can compare oranges to oranges...

I'll take any reliable info I can get!!

Fair enough. Suffice to say, a rich,15psi tune with your setup (cast manifold, iwg 8374) on a car with stock ports (or maybe street port, not sure if previous owner knew what the car had) and water meth should safely and reliably (minimal boost creep) do 350-400 @ the wheels and spool noticeably quicker than a gt35r? That is the basis of what I'm looking for. My gt35 not significantly spooling until 3500+ does not cut it for me.

Interesting. If your "safety threshold" is 12psi on pump, in your opinion how much more wiggle room would water meth add to this equation. 3-4 psi? Im still surprised at your recommendation on a 8374 after you've tasted the resonse of the 7670. Any chance you have ridden or driven a comparable 8374 equipped car back to back with your 7670 to see the response difference on the street or in the twisties?

15 psi on pump gas with a rich tune will make anywhere from 380 to 430rwhp depending upon porting( stock to large street port).

I ran 29 psi for 3 straight years and 4 drivetrains later on pump with meth. I have tuned multiple cars on the above at 600rwhp with zero blown engines.

aplscrambles

Interesting. If your "safety threshold" is 12psi on pump, in your opinion how much more wiggle room would water meth add to this equation. 3-4 psi?

I personally wouldn't do water meth for a several reasons.
A) It isn't allowed in any racing class with the organization I race with.
B) I don't consider something else that can fail a good safety net.
C) I don't need the power on the street. I can use race gas at the race track

I consider 12psi safe on pump gas because I have had several engines let go immediately after getting gas on 14psi on my 8.5:1 rotors and 10:1AFRs - leading me to think the premium tank was empty and I got all 87 octane or the pump wasn't switching or the gas station was crooked.

12psi is safe for those times you get 87 octane when you pay for 91.

Im still surprised at your recommendation on a 8374 after you've tasted the resonse of the 7670. Any chance you have ridden or driven a comparable 8374 equipped car back to back with your 7670 to see the response difference on the street or in the twisties?

I haven't experienced an 8374 yet, but it is the turbo I would get for low boost on the street. The videos show great response and the dynos show spool very nearly as good as the 7670.

I bought the 7670 for high boost/race gas on the autox course, that doesn't sound like what you want.

I can't see much point in fitting the 7670 . It must make a lot of hot air at any boost level you run it at and spoolup is only marginally better than the 8374 . Just doesn't make sense to me to use it in any situation where you want better than stock performance.
I think if there was something like an 8070 .... where the compressor is half way between the 76 and the 83 ............. That turbo might be worth considering over the 8374 .Then again how good to you need spoolup to be ? Doesn't the 8374 do everything you want as far as spoolup goes ?

Point of 7670 would be when you don't think you can use any more than ~450rwhp and you want the best turbo response.

Stock sequential turbos can't touch the low/midrange torque of the 7670 on high boost.

Well, I might try the stock twins in serial (compound) mode switching to parallel to get the low/midrange torque of the EFR though high boost- but no one has done this yet.

So the 7670 would shine in racing (with race gas) in a parking lot in 2nd gear, on a kart track or a single lane road (European hillclimbs).

Even with the 7670 I would have welcomed faster boost response.
It still takes half a second to hit 26psi at which point you are getting off the throttle and setting up for the next turn or grabbing the next gear on these kinds of really tight courses.
It only takes about 2 to 3/10ths of a second to get the throttle to 100% so you can definitely still feel the lag. Its not quite like driving a big displacement V8 yet.

Im wondering if 1.05EWG 7670 would be a fix for the strained top end performance i'm seeing on the dynographs getting posted..? On paper a compressor that size - especially extended tip - should cheerfully do its job to redline at moderate pump fuel friendly boost levels without dropping off. Would probably be the most likely to fit to a conventional aftermarket manifold in a tight engine bay too (not everyone has an FD, lol).

I see your point .... where you aren't revving the engine out to redline for any sustained period ..it makse sense.