soviet

iTrader: (10)

I made 330whp on wastegate (like 15-16psi?) on my last dyno running ALLOFIT timing map and E85

Leafy

iTrader: (1)

What dyno was that on? Remember the DIYAT one reads like 16% lower than a dynojet (supposedly), so that wouldnt even crack 290 on their dyno.

shuiend

iTrader: (24)

Also need to account for e85 vs 93 octane gas difference.

soviet

iTrader: (10)

People keep thinking that 6758 is a big boy turbo - it isn't. It's a pretty small turbo that just HAPPENS to be able to flow ~53lb/min.
It has compressor and turbine wheel dimensions a little bit smaller than GT3071R but spools like a GT2560R.

Plus >dat transient which doesn't show up on dynos.

I always dynoed on calibrated dynojets with SAE correction.

Yeah its like more than 10* of timing difference.

Ryan_G

iTrader: (8)

I think soviet's overlay of the 6758 at 27psi shows what the efr series is designed to achieve. Spool like a 2560 or small t25 with a lot of extra room up top. You don't put the efr on to run the same psi. You put it on so you can maintain the driving characteristics of your small turbo and crank up the boost for more top end. That 2560 is maxed out in Ben's dyno. The efr is not even close.

I have also heard that the new 7163 is acl second gen design and should perform even better than the original b1 frame turbos. Mine should be up and running before the end of this year. I will max it out on gas and e85 (now that its available down here). My motor looks a lot like soviet's except it had vvt and has 83.5mm 8.6:1 instead of 84mm 9:1 pistons.

soviet

iTrader: (10)

fapping with both hands.

hrk

iTrader: (6)

Hello,

I am lurking away here now, Thanks shuiend for inviting me to the party.

Yes, the single most expensive part ever in my car appeared to have failed to improve the motor.
This 2560, which was for sale https://www.miataturbo.net/miata-par...ops-etc-69843/
Did make great results, both driving and in dyno. Links have been posted in this thread previously. Motor was just built, as thoroughly as I was able, some info here as well. And it ran great. Old log manifold included. Couple of 5-speeds can vouch for that. they last 54 minutes of running at speed.

Of course, the logical thing is to get more, and going from 110% loaded turbo to bigger one would make sense.

I was in contact with Borg and Warner after dyno and last Dragon Hillclimb and I was left with several issues to work on or check.
1. Wastegate actuator, getting high boost actuator from B&W. I am running with electronic boost control from MS3X.

2. Exhaust manifold. Same on both setups. Yeah yeah yeah, why it worked to the limit on old setup and now doesn't with new turbo makes me think this is not the reason.

3. Trying with higher boost. 6758 is said to respond well on 20+psi boost compared to Garrett, which should be kept below 20. Sizing, efficiency and exhaust flow may have something to do with this.

In addition I should do through check on the motor, for Garrett, everything was new, fresh and put together well. For Borg And Warner there is about 90 minutes of runtime (one and a half transmissions), and no obvious signs of issues.

The reason I asked not to tout about results in March when we did the test was that I wanted to know what is going on myself before blaming turbo, but I haven't found motivation to dig into it. Maybe this discussion gets me motivated.

hrk
Discuss.

Ben

iTrader: (33)

Do you have a plot that includes manifold pressure?

Leafy

iTrader: (1)

Right I keep forgetting that the EFRs have the waste gate blowing open issue. Going to a dual port IWGA and using a 4 port EBC should fix all of that and still allow you to run a really low spring in the IWGA to have better part throttle characteristics.

EO2K

iTrader: (37)

I'd be nice if someone made an adjustable dual port that would fit the B1 frame.

soviet

iTrader: (10)

I have a log somewhere but its flat to redline, I don't gain or lose manifold pressure, its flat. Just more timing to redline.

Leafy

iTrader: (1)

Turbosmart does, but you have to add the nipple for the 2nd port yourself. They just ship it with a set screw there. OR do you do what I did and get some actuator from south east power systems, make a 1/4-28 threaded extension and drill the holes out on the bracket a bit to get a 7psi dual port wastegate. It cost way too much money for what it was, but it was the only dual port option at the time and that was the direction I wanted to go with. It also doenst have enough stroke to fully stroke the EFR waste gate, which is why my car tapered to 10psi at peak power then tapered back off when I ran straight wastegate.

18psi

iTrader: (76)

nvm

concealer404

iTrader: (3)

Here's the link:

https://www.miataturbo.net/showthread.php?t=77361

I know we dont really have other 20psi dyno charts, but you think Soviet's stock head car is going to pick up 150whp by just adding 8psi over this?

Leafy

iTrader: (1)

4 port is on the too do list still. I'm waiting to do it for the next time I dyno the car.

soviet

iTrader: (10)

dude I made almost identical TQ and HP on same turbo (he is using 6258, and so was I, 2 years ago)

his:
http://i1084.photobucket.com/albums/...9.jpg~original

krissetsfire

iTrader: (1)

Seems about right. He's rockin' pump gas too. So ~8psi + e85 = 18.75hp per psi?

soviet

iTrader: (10)

past 20psi its like 5 hp per psi and 10 hp per 1* timing.

the key difference is that the 6758 can flow enough air to support >450whp where as a GT2560 does not, no matter how much timing you run.

shuiend

iTrader: (24)

I think this is the real thing. If you want more then 300hp at the wheels then and willing to run allofit then the EFR is a good choice. Otherwise the 2560 is still a pretty good choice.

I think the real comparison we need to have is my 2871 vs a 6758. Hopefully one day I will actually get my car back together, head down to DIY and run allofit.

Leafy

iTrader: (1)

I dont care what the dyno says. The 6758 is a better choice because its like a v8 swap, rather than adding a turbo.