pdexta

iTrader: (17)

We could take bets on what piece of the drivetrain flys the farthest.

Leafy

iTrader: (1)

Lol, I'm leaning more towards the 4 speed options for straight cut gear, dog box awesomess. But I've got other needs before I need more power. But dont worry, when I get out to dyno again in the spring I will be over 300hp on the 5 speed. Until them I'll continue living vicariously through soviet.

soviet

iTrader: (10)

my wallet

I think I decided on what I want to do next with the car, and you all may be dissapointed

I want
- Rewire
- A nice interior
- Flex fuel (Megasquirt implementation has come a long way)
- To actually do track days

AbeFM

iTrader: (3)

-In full support
-Not unless it looks better in the videos
-SUPER curious how this works out. Not sure I'd build a car like that without it.
-Don't break pretty car.


Also very curious here. Hard to translate, I'm sure, but how are the transients? If the smaller turbo is ONLY putting down 350-400 hp, but spools even better.... Seems like a pretty viable option for some folks.

soviet

iTrader: (10)

Well.
The 6758 takes pretty much 30psi to max out
The 6258 maxes out at less boost, low 20s, like 22psi or so.

Yeah the 6758 gets full spool at 3700 but it still takes time to go from 0 to 30psi. More than a second, to be exact. I mean yes, if you're in right gear and right rpm its much faster but big boost is still big boost. Yes the car is hauling *** all the way to 30psi but its still a massive amount of boost to build.

Basically 6758 is exactly like 6258 but it goes to 30psi instead of falling off at past 20ish. At low boost they are almost the same.

Ian

iTrader: (2)

Great numbers, but what's really impressive is the AFR with a maxed fuel system. That **** is near perfect the whole way through. Nice

soviet

iTrader: (10)

Yeah, fuel system was problematic past months but I've figured it all out. Everything performed perfectly.

AbeFM

iTrader: (3)

Really jealous of it. What did you use for a return line? Oh! The OEM setup HAS a return line, no? Not so on the NB's, but I guess I could recycle some of the carbon canister stuff.

It seems like a waste to use an expensive pressure regulator - I just have no idea if the spendy ones are better or just spendy. I've never heard of someone having issues with a cheap one - only them having a good one and it working out. :-)

That pretty much parrot's BW.... Their basic philosophy (so different from my own, uneducated and gut feeling of "get the smallest turbo to achieve the HP you want") is "get the biggest turbo that meets your expectations for spool".

muoto

so if this thing made 458whp in real dyno and 435whp in virtual dyno.... there's a good change that I'm way over 400whp too with my 410-430whp virtual dyno pulls

And I still have an old .64 gt2871 same rocket fuel though
(well, my gt2871 is 56trimm version so basically its gt3071)

Corey

What makes me even more impressed is that I could point Leonid towards a different local dyno locally to us where he could probably post numbers showing 500whp.

18psi

iTrader: (76)

who cares at this point. the car is obviously bananas. I seriously hope to see some good action vids of this thing.
Kinda confused me with this statement: so it does spool faster or it doesn't? Like lets say both were targeted for 300whp, would the 6258 have faster reaction and recovery than the 6758 at that power level?

It'd be really neat if you had turbo speed logs of both, but oh wellz.

Braineack

iTrader: (62)

yeah and he could drive to AUS, strap his car upside on a Mainline dyno and produce 7345 ft-lb of TQ.

soviet

iTrader: (10)

you should be! 2871 and 3071 turbos both have 53.1mm compressor wheel, where mine is 53.9mm. I'm surprised you use the smaller AR, though. Small AR and 3.5" exhaust, lul

soviet

iTrader: (10)

yes, same boost, a 6258 would be faster both due to smaller compressor wheel. But who stops at 300whp? Really now.

Nagase

iTrader: (6)

I'm curious about transient response between the two as well. How's the difference in corner exit between the two turbos?

soviet

iTrader: (10)

If you're on track you will be always in boost, like 5-10 psi all the time. There is no noticeable delay in spool.

Here's a video from last year to refresh your memory. That was a 6258 on ~12 psi (like 250whp?)

18psi

iTrader: (76)

lol

us peasants

soviet

iTrader: (10)

What I mean is that 300whp is not a breaking point in any of the miata hardware. Either you get stuck at 250 because stock internals/5 speed or you go as high as the turbo allows, because built block/6 speed is good for more than 300whp.

Nagase

iTrader: (6)

The sound is really bad in that video, can't tell where boost starts or ends.

So, could you compare the two on the street? Or any situation where transient response matters?

How are you managing to stay 5-10 psi on track in the corners and under braking? I'm not seeing how the 'all the time' is managed. You LFB a lot?

Corey

Drive to Australia? Now that's a bit far-fetched, don't you think?

Wish you could have been at the meet, man.