Trackspeed EFR6258 w/CNC Head
 

Power mods are finally complete! Build specs:

Trackspeed Stage 2 shortblock
-Supertech 8.6:1 pistons, 83.5mm, thermal coating on crown
-Manley Rods
-Boundary Engineering billet oil pump
-ACL race bearings
-Supermiata damper

Supermiata CNC-ported BP6D (VVT) Head
-Stainless Steel intake valves (+1)
-Inconel Exhaust Valves (+1)
-CNC porting
-Supertech Light Double valve springs
-Stock cams
-Stock lifters

Trackspeed EFR Turbo System
-Cast Stainless Steel manifold
-BorgWarner EFR6258
-Precision 350hp intercooler
-Medium wastegate canister

Other
-3" mandrel bent exhaust from turbo back
-Ceramic coating on manifold, turbine housing, downpipe, midpipe
-MS3Basic
-LS2 coils
-ID1050x injectors
-VICS Intake Manifold
-Skunk2 Throttle Body

Graph shows the runs from each iteration of my build, starting from bone stock. Red and blue lines are the current high power and wastegate tunes, respectively.


https://cimg4.ibsrv.net/gimg/www.mia...379ff596e9.png

Nice!
How does it feel?

Nice. :party:

And insane. Still on 205 tires, so I don't have full-throttle traction until 4th gear. Certainly gets up and goes though! Haven't had a ton of time driving it so far, been trying to track down a speed-based vibration. On new driveshaft #2, but still have issues above 80mph. Heading back to the shop for more diagnostics and possibly New Driveshaft 3: Carbon-fiber Boogaloo.

I love the comment at the bottom of the graph: "Turbo and other cool things. Nice story bro."

So what is going on here. What boost pressure are the two graphs coming in at. Wastegate is the 7psi? Or do you have something bigger?

Are you running a boost closed loop strategy to hit a certain psi?

Are you surprised that the torque curve tails off as much as it does? Would expect that higher flowing head and intake manifold to help prop that up.

He's still on a VICs manifold, square top or S2 would help with the fall off up top.

Wastegate was a hair under 9psi, high boost was 18psi.

Open loop boost control for now, I need to tune it at the very least to get a decent bias table, there are plenty of online writeups on how to dial in your closed loop boost control that Don doesn't need to pay an hourly rate for me to watch and follow the instructions.

Wastegate is right around 9psi, the higher power EBC-enabled graph is at around 18psi. @curly did the tuning, so he should be able to answer the rest of the questions. Timing was kept on the conservative side from what I understand, which may explain the drop off on top. Could have also been an intentional tuning decision to keep the 6-speed alive on track. I'm actually more surprised by the big torque peak, since I am running pump gas. A few other dyno charts I was looking at were 10-20 lb-ft lower.

EDIT: Josh beat me to the punch!

Looks like a blast!

looks good, makes a bunch of torque but does drop off faster than I would have expected. If the torque would hold longer thats an easy 330whp. Still though I bet it pulls hard.

Very nice :)

@curly, there's a bit more to be had in the low end. I have a local customer with a near-identical setup (Stage 2 8.6:1 bottom end, CNC +1/+1 head, VICS IM, E85) and we are seeing 200tq at ~3100rpm on that car. You may be able to add a tiny bit of wastegate preload to bring the cracking pressure up without inducing creep on the top end. With NA heads or stock NB heads you can overdo it with the preload and there's not much of a penalty, but with heavily ported NB heads it's a very fine balance between too little preload (low cracking pressure, lazy boost onset under 4000rpm) and too much preload (boost creep at higher RPM). It is possible to get the best of both worlds, though. I would do that before you start digging into the EBC too far.

Squaretop would be worth, oh, 40whp on this car with no other changes. :party:

Clearly I need more tire.


And aero.


And skill. :ugh:

Preload was one of the things I was going to adjust on the dyno, but we were worried power would be too high with the cnc head and built motor even on wastegate, especially while Don re-learns the car in forced induction mode on track. So when it made "only" 220, I decided to leave the preload as is for now.

It all depends on if it's creeping up top or not. If boost rises all the way through the run, then you don't have any wiggle room. If boost is stable, which it appears to be based on the dyno, you may have room to add preload and still hold that same boost level up top. The low-boost actuator and a CNC NB head at 8-9psi is pretty much the absolute limit of the EFR's IWG, so it takes small adjustments to find perfection (like 1/4 or 1/2 a turn a time of preload).

Using the medium canister, so might have a little preload to play with. Should have time to fine-tune things after the 15th and my work schedule slows down.

Send us a pm and we'll take care of the squaretop for you. Will be interesting to see a before and after.

Don, send me a full throttle pull to red line if/when you adjust preload, I can double check the fuel map looks adequate for the earlier boost that should create.

The fun budget is pretty much blown at this point, but when/if I get the itch for more power I’ll drop you a line!

Can do. Won’t be for a while though, got to get through tax season first.

Looking good.

Your timing is likely pretty conservative, as i made 309whp and 273tq on 17psi. but with a rods only motor, 94 pistons, and a 200k mile untouched vvt head.

On my Medium boost canister, wastegate only, the boost starts at 9psi and then jumps to 10-11psi and holds to redline. making 250hp, so its interesting to see yours actually holds 9psi to redline. maybe you have slightly less preload than me.

My setup is likely pretty maxed out, You have lots more power to unleash!

heres my dyno:
https://cimg2.ibsrv.net/gimg/www.mia...e1aa0717a9.jpg

Post your timing map, if you dont mind, i am curious to compare it to mine:
https://cimg5.ibsrv.net/gimg/www.mia...2bb99a91af.jpg

Kinda sounds like they want you to show everyone why they should buy a squaretop them. I think they are offering the manifold at no cost, you should pm them IMHO, I could be wrong. :dunno:

^^^this is how I read it too.

If only I could get Kmiata to be on board sponsor a kit for my twin scroll *allofit* before and after experiment :rofl:
(but they definitely deserve every bit of return for their R&D, addressing a market gap that was in dire need...plus Made in America)

Not giving away for free haha, but he might be able to talk us into a discount once he gets it back on the dyno with the squaretop and show the results ;)

I would love to see this setup with a squaretop as well. It would be interesting to see the gains past 5500 rpm since that seems to be where the squaretop really shines.

"Conservative" were my instructions, since this is more of a streetable track car than a trackable street car. Wanted to make sure the tune would be safe on pump gas (including CA91) while heatsoaking everything under track conditions. When I fiddle with things over the summer I may even work on flattening out the torque curve a little to make 3rd gear easier to manage.

I'm interested too! However, I already have more power than I can realistically use right now based on my setup and my (limited) skill. Power-adders are going to be pretty far down my list of things to do for the foreseeable future. My next set of tires will be 225s, we'll see how much that helps putting the power down. Next frontier will probably be aero, but I have a lot of learning to do before I can make good use of the additional capability.

You are reasonable. You will live a long and prosperous life.

Really similar. About 4 degrees less at 160, at 220 I'm at 14 degrees, but only drop to 13 at 240 vs. your 11 a 250. Definitely splitting hairs at that point.

This looks like a nice graph! I am just surprised I can hit the same 175ftlbs at 3200 rpm with my stock 1.6 and TD04L-13T. But I get blown out of the water after that. Really drives home how well these things spin up for being such "big" turbos!

Thanks, my 250 kpa zone is really there only as a safe retarded buffer, so i dont blow up if i suddenly have a major boost spike.

My thread (https://www.miataturbo.net/dynos-tim...unk-2-a-99000/) already proves the gains found with a Flat Top. It then goes on to show the substantial improvement with a Skunk2 and the 0.5L spacer. Extrapolating from my results with a GT2560 turbo and FM hot side, This car should make 330hp all day long.

Very nice.

For Science, I would be willing to loan my port matched Squaretop (to Skunk2 TB) to see what happens to the dyno plot, if you want to do some more pulls and see what that investment will net you.

In your esteemed opinion how much midrange do you think you'd lose compared to the VICS, or would it be negligible compared to the gains up top? I've currently got a VICS inlet on, and a squaretop sat gathering dust in the garage - for primarily a street car which will sit at the midrange area not way up top is it worth swapping over?

Yeah Ken Hill already has this well documented guys. Look at his thread. Surrender your cats.

Ken's very helpful thread is VTCS vs. Squaretop, not VICS. Other threads have been a lot less conclusive - VICS seems to give a bit more midrange than a squaretop, but drops off a bit at the top end (but not as badly as the VTCS).

I know that Savington has built customer cars with both VICS and Squaretop manifolds - and in my hazy memory said that sometimes on a street car there are situations where the VICS may be preferable..

The only reason I use a VICS manifold in certain builds is to tamp down on high-RPM power for specific race classes (ST4 or Supermiata S1). In those classes, it is easy to select the "right" combination of parts and end up with a car that refuses to make less than 240-250whp, even at low boost. The EFR's turbine is so efficient (compared to the common Garrett T25/T28 turbine configs) that any decrease in intake restriction will result in a system flow increase, even without increasing the measured boost level. By using the "wrong" parts (VICS manifold), I can maintain similar mid-range torque and tamp down on top-end flow, effectively avoiding those issues.

In cars that jump between race classes, I can then just turn up the boost and blow 300whp through a VICS at 2-3psi more than it would take to make that power on a squaretop, because the EFR's high-PR compressor efficiency lets me do that too.

On my own 450whp street car, I used a Squaretop.

IOW, I use the VICS manifold as a built-in power restrictor. If you don't want to restrict power, don't use one ;)

Great explanation, thanks. Guess that's another job that needs to be added to the list then :)

So, about my offer ... :)

I call shenanigans

Sorry for the delayed reply, been neck-deep in work.

Mobius, thank you for your generous offer. However, at this point I'll have to pass in the name of marital harmony. Going to try and keep my time in the garage to a minimum this summer.

That being said, if I recall your motor is largely similar to mine (+1 CNC head, 8.6:1 pistons, etc.) save for the intake manifold. I'd be willing to share dyno time for science and we could do same-day runs once build v.3.0 is up and running.

We'll see what the future holds, but at this points I don't have any plans. Sure, there are lots of things I could do, but if I'm going to spend more time/money on more power I want to make sure I can use it. That means 1). driver mod and 2). aero come first.

Do you find that the VICS makes more torque down low or is that just poppycock?

I think Ken's test is the best one I've seen so far, and he showed the Squaretop picking up a bunch of mid-range over a VCTS. The VICS makes more midrange too, but not enough to be better.

If it is better, we're talking 3-5tq at most, and for that small gain, you give up power starting at 5500. It's a stupid tradeoff IMO. If you want the "best" manifold, full stop, you buy a Squaretop (or you deal with a Junk2 and its fitment/reliability issues and add plenum spacers).

If you have VTCS and are going through the trouble of changing manifolds, get a squaretop or S2 like Andrew said.

If you're fully broke and insist on changing the intake, VICS offers significant gains over VTCS. But with squaretops going for well under $300 these days, it's silly to spend $100 on a VICS.

Our setups are quite similar except you have vics and 8.6:1 pistons, while I have squaretop and 10:1 stock pistons. I don't yet have a full 3" exhaust either.

Not sure when I'm going to be running boost again, little things I want from Andrew like a radiator and an intercooler are out of stock with no ETA. There are workarounds I suppose if I get to where I'm ready to drop the engine in.