515whp EFR6758 build
 

Just a data point, thought I'd share.

We no longer offer built engines. This one we shipped to a customer back in 2015.
TSE EFR6758
E85
84.0mm 9.0:1 pistons
Moldex billet crank
Tomei cams
Supermiata CNC BP6D head, +1 stainless intake, +2 Inconel exhaust
Carrillo H beams
Billet oil pump gears
Supermiata damper
ACL bearings
Oil pan baffle plate
Supertech heavy double valve springs
Supermiata SUBs

I think this motor still has more on tap with additional tuning. For reference, we made around 440whp with a 6258 and stock cams on a similar build.https://cimg8.ibsrv.net/gimg/www.mia...500eb7d1ba.jpg

Thats a lot of power, thats awesome. But has a Garrett guy I have to wonder why these EFR turbos arent spooling faster. I thought they were the best spooling turbos ever? I must say though thats a nice looking curve inspite of the slower than expected spool.

The graph might look mis leading. That’s 300hp by 4250rpm, stock cams, less boost, and that curve would flatten out nicely I’m sure.

As mentioned in the post, that plot is by no means the maximum that particular hardware combo is capable of. As Josh mentioned, stock cams will spool faster. I just posted because I haven't seen any 6758 plots here. My 420whp 6258 plot with stock cams and a few others around the same on stock NB cams is all.
Based on what we have done in our shop, I think this hardware should be capable of another 100whp from 2500-4000, pull to 8,000 and peak at 560whp or so. We once briefly touched 440whp at around 5500 with stock cams with our 6258 before blowing the spark out. I'm convinced we could have hit 450~460whp with IGN1A coils, but we stopped development there. Thus, I think the 6758 with cams has a more in it.

Yarp. Tomei BP6D cams are asleep until 4500 even N/A. Stock cams will spool faster as you said.

Ahhhh, I missed the fact that it has Tomei cams. That makes a lot of sense now. I mean at 500whp a miata is stupid fast, I can only imagine how this car must feel.

I remember your allofit 6258 plot at 25-26psi you were making really good power on that as well.

Having tuned the new gtx2863 and efr6258 personally just recently I can say they are similar in spoolup. When compared to the old stuff, it's no contest, efr wins.

Cool man thats good to hear. Transients probably still a nod to the efr however with its gamma Ti turbine.

Talking to owner, they had ECU set to cut fuel and spark for rev limiter. They did a routine scoping and notice a tiny bit of det damage to one piston so they're pulling it down to put new pistons in.
I could be wrong but I suspect that fuel cut at rev limit (8400rpm) might be the culprit. Personally I always do hard spark cut on our race engines, leave fuel on. Better to have that latent heat of the fuel mass doing some work cooling bits off on overrun IMO.
Made a few other suggestions on tune WRT to spark, VVT and a few other tables. Curious to see how much more they can get out of it.

Yea, I agree 100% on the spark cut and leave fuel on. Just seems much easier on the engine and also possible fireballs from the exhaust. Let's be honest we all love fireballs.

How much damage on the piston? Probably slightly deformed on the intake side I'm guessing.

Just a tiny dot on one piston. But the owner is playing it safe.

Yah, more fireballs.

what boost level are you running to get that? Can you share a spark map?

I'm finding that I can't get above 400hp at 27psi on my 6758. But I don't have larger valves or cams. Also, I'm at 5200ft.

400whp uncorrected in Colorado out of a BP is a BIG challenge. I haven't been able to get there yet either.

Not mine to share. Its a customers build who wishes to remain anonymous.

If you haven't already, I'd start a new thread on your tuning questions. I'd want to see screen caps of VVT table, VVT settings, Ignition, boost duty, fuel, AFR targets, injection timing, rev limiter settings and pic of intake... in a new thread.

Nice numbers :likecat: I'm trying to get same power leves with EFR7163 and stock BP6D head

What transmission are they using?

Don't recall. Not an AZ6 though. When we built this engine for them we let them know a stock AZ6 would frag at half the power this motor would be capable of. So they did some sort of trans swap from the get go.

If 4th gear was stronger the AZ6 would be probably alright until 400ftlb. Ive already broken one 4th gear, is that typically all that breaks on them? I too would like to see more info on this setup if the owner is willing.

What transmission did you use to handle that much power?

What's holding it back up top? Even if revved to 8000, horsepower has already peaked and started falling off at ~6000. I don't mean that as a slight to the setup at all, just curious.

Excellent question. As mentioned in an earlier post, I asked the owner to send the tune file. Saw several things that would affect the power adversely. Made some suggestions. They'll retune after Keegan Engineering (that built it originally) puts new pistons in it.
Tune is not mine to share. But yeah, on paper, this combo should make a bunch more up top and spool faster as well.