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Nice Job getting all of that fixed / repaired in a relatively short period of time. You keep improving the car every time.
BTW...Awesome job on that oil pan. Most professionals wouldn't have tried welding it after it's seen oil. (or at least that's what they said to me when I tried to get mine done.)
The gearing(4.3+6spd) make this car a rocket though. Spins first, second, and chirps third on cold tires. Lots and lots of shifting is the obvious downside.
Don't even think about a 4.7/4.8 diff then. I put a 4.77 in my racecar, because I wasn't using 6th anywhere with the 4.3 - mistake! It was just so busy shifting that I ended up making mistakes. After I went back to the 4.3 I was told the secret of those low ratios is to short shift as much as you can, the corollary being that you build the engine for torque/wide power band rather than peak power. I don't think it would have made much difference as my engine was already built with a flat power curve (as far as these go), but maybe the short shifting would have worked but there are some tricks this old dog has trouble with, and it seems that is one of them.
Good work on the oil pan, I have wondered about the vulnerability of those and whether there was scope to do that, so thanks for posting.
I'm going with the 4.3 and 6 speed as well. When I did most of my calcs for the tracks that I run on, I found that either it didn't change the amount I was shifting or it actually reduced the amount I would need to shift. It probably feels like a lot of shifting on the street but with that combo you will pretty much never use 2nd gear on track anymore. On my local tracks it will just live in 3rd/4th most of the time and touch 5th on the main straights, where with a taller rear end it would be using 3/4 a lot but also have to touch 2nd in slow corners as well as using 5th on some straights. The big big tracks will get into 6th but that's like Road Atlanta and Road America type stuff.
Good job on modding the oil pan, I've wanted to do that to mine as well ever since I saw it, no idea why they would hang the damn pan so low when there is that much clearance inside.
We seem to have very similar setups now with similar feedback
I maaay have taken a small amount of inspiration from your setup.
Originally Posted by Gee Emm
Don't even think about a 4.7/4.8 diff then. I put a 4.77 in my racecar, because I wasn't using 6th anywhere with the 4.3 - mistake! It was just so busy shifting that I ended up making mistakes. After I went back to the 4.3 I was told the secret of those low ratios is to short shift as much as you can, the corollary being that you build the engine for torque/wide power band rather than peak power. I don't think it would have made much difference as my engine was already built with a flat power curve (as far as these go), but maybe the short shifting would have worked but there are some tricks this old dog has trouble with, and it seems that is one of them.
That method would seem counter intuitive to me, would think for tight gears you would "want" a peaky powerband, since every shift isnt dropping you out of said powerband. Definitely no thoughts of a 4.7. If anything I'd go to a 3.9, but I wanna keep the tighter lower gears for hillclimbs.
Originally Posted by Arca_ex
The big big tracks will get into 6th but that's like Road Atlanta and Road America type stuff.
Good job on modding the oil pan, I've wanted to do that to mine as well ever since I saw it, no idea why they would hang the damn pan so low when there is that much clearance inside.
Road Atlanta is my home track so I'll definitely be using 6th there. Will probably be a 3-4-5-6 track with only a brief touch of 3rd in T7, if at all. I might be closeish to limiter on the back straight. Should be able to test that theory out in December.
The only reason I can think of for the extra deep front sump is additional oil capacity. But the damn thing already holds 6qts and takes forever to get the oil up to temp, so loosing even a half quart of that isn't concerning to me.
That method would seem counter intuitive to me, would think for tight gears you would "want" a peaky powerband, since every shift isnt dropping you out of said powerband. Definitely no thoughts of a 4.7. If anything I'd go to a 3.9, but I wanna keep the tighter lower gears for hillclimbs.
Road Atlanta is my home track so I'll definitely be using 6th there. Will probably be a 3-4-5-6 track with only a brief touch of 3rd in T7, if at all. I might be closeish to limiter on the back straight. Should be able to test that theory out in December.
6spd/4.3 combo works great with the K IMO. It worked REALLY great with the BP, keeping the poor little engine in the better part of the power band .
With the K having so much more head-room of RPMs it's very unlikely for you to end up with more shifting over a 5spd. Road Atlanta does benefit from 3rd gear in T7, it's ~5500rpm with a 50mph min speed there. The other turn that benefits from 3rd is T10A/B. The down-shifting from 6th to 3rd into it can take some getting used to, but I think 3rd was worth it to continue up the crest after 10b. Though..... I've only done it with 170rwhp @ 2600lbs so you're setup might be juuusssttt fine in 4th with the extra 50hp/40tq(**** lol I just mathed that) and more importantly way less weight(300lbs less?)...... Man I wanna go back to RA in TT4 trim after typing this out .
If you want an inspiration on "Is 4.3/6spd the right combo?" you can watch TomO's lap at NCM in my car
The 6spd also took some getting used to.
The gearing(4.3+6spd) make this car a rocket though. Spins first, second, and chirps third on cold tires. Lots and lots of shifting is the obvious downside.
I've been 6/4.3 for years behind the BP and picked up a 4.77 to load my new-to-me OSG diff into.
Are you always running a wide open, full power, no de-tuning map?
What rev limit?
I've already sold myself on the 6/4.7 assuming a restricted sub-190whp power level and a ~7800rpm limit, but love to second guess myself.
Also, I think shorter gearing is 100% da way for hill-climb.
Hillclimb gearing and the additional cost of sourcing a 3.9 are the only reasons I don't have a torsen 3.9 ready to stuff in. Being able to stay in the powerband for 2nd gear hairpins is going to be critical for courses this year.
Originally Posted by doward
Are you always running a wide open, full power, no de-tuning map?
What rev limit?
Full power tuned to MBT on the dyno(210whp on 93, 230whp on E74) with a normal 8K redline. I've bumped it to 8300 for one event(due to gearing) but otherwise stick religiously to 8K. I think peak power was 75/76ish with a fairly flat torque curve.
93 I use for getting to/from events and a few sessions/laps for learning new courses, then I load up with ethanol for the rest of the weekend. No restrictions or detuning.
SOOO I've been sitting on this for awhile for... several reasons. But I don't think the people I don't want to know about this, read this thread(my hillclimb competition). If they do, welp, I've shown my hand a little early.
Originally Posted by Wingman703
4 Piston makes a set of billet cams for the R40 head. At $2400 they are pricey, but also comes with an adjustable exhaust gear and billet rockers. Advertised as being worth ~30whp on an otherwise stock engine.
4Piston's goodies *should* be worth ~50whp, which puts me in the ~280whp relm on E85, and probably ~220ft/lbs for torque.
I think I'll just do the cams+valve springs+CNC porting. Should be a nice ~50whp bump, have some additional overrev protection/valve control, and won't loose any reliability.
Yeah, this didn't happen. Literally THE DAY I went to hit "buy" on 4pistons cam setup, it went out of stock. They came back about a month later with updated parts and a prebuy, but by then I had already committed elsewhere.
I took the 4P cams going out of stock as a sign. so I went with my other option instead.
I've dropped a few background hints and clues in this thread, but...
G25-660, .92AR, Vband. Garrett's newest small frame turbo line and a step up from the GTX family, capable of 600+whp on pump gas, lightning spool, all in an incredibly compact package.
I've been sitting on this bad boy since early September.
Kpower's K24Z3 to Vband manifold. A nice piece for sure, but gawdam these are pricy($700!)
And, when combined, turbo no hit valve cover. Barely.
Obviously nothing off-the-shelf fits my not-off-the-shelf-exhaust, so I built a downpipe with way too many piecuts.
Painted, wrapped to help protect sensitive items in the engine bay, and O2 sensor moved to its new home in the wheelwell.
The turbo is so small, there was no room to fit a 10AN fitting between the housings, so I built what I affectionately call the ***** to drop the line down 3-4". Oil return is plumbed into the timing cover plate, I had my buddy JB, weld the aluminum fitting to the steel plate, and its held up so far.
Oil is fed from where the "VTEC pressure switch" used to be, I think it was an M10/1.25 threaded fitting, just adapt to 4AN and you're set for a nice short oil feed.
Plumbed some rubber water lines from the block-turbo-radiator and fired her up sans intercooler piping.
Drove it to work with the turbo venting to atmosphere and built intercooler lines.
Oh man, that first boost hit of a whopping 2psi... that was the biggest giggle session I've ever had. Screw your N/A throttle response, turbo noises are where it's at.
Currently have "low boost" set for 5-6psi in all gears, and "high boost" setup as boost by gear. First and second run 5psi, third is 7psi with 4/5/6 ramping up to 12PSI. I have absolutely no idea how much power its making as its not scheduled to be on a dyno till after Thanksgiving. It IS a rocket, 1-3 all spin, 4th slide if it's not dead straight, and 5/6 still attempt to relocate your guts while reaching illegal "you go to jail now" speeds at a freighting pace.
(Yes, that switch turns on the boost controller)
First start, quick 1-3 gear pull on low boost, and a loooooong spool down(modern ball bearing turbos are WILD)
So far I've had it running for about a month, with only a handful of turbo issues(some fluid leaks, studs snapping, exhaust leaks, the normal new turbo stuff).
Week after Thanksgiving it goes on the dyno to see how far over that 250tq transmission limit I am.
Few days after that I'll be at Road Atlanta with NASA for TT. If the weather is dry I'll take a crack at the overall miata lap record and try not to die doing 150mph in this rocketing deathtrap.
I haven't hit 150mph at RA in a Miata and don't think I want to. Going that fast on a big, open track like Daytona prompted me to put a full cage in my car. And there's a lot more room at Daytona.
No, the pull in the video was 6psi. And lots of tire spin.
Originally Posted by flier129
hell yes!
Yeah baby, its party time!
Originally Posted by sixshooter
I haven't hit 150mph at RA in a Miata and don't think I want to. Going that fast on a big, open track like Daytona prompted me to put a full cage in my car. And there's a lot more room at Daytona.
You be careful out there.
I'm under no illusion to my own mortality. While I have no intention of prematurely finding out what's afterwards, or what life as a quad is like, I definitely recognize the risk. This car probably needs more than just a rollbar, but I'm currently at a loss of trying to figure out how to keep it streetable(i.e, no 2" metal sticks next to my head and working windows) while obtaining a reasonable level of "safe".
But yeah. It's a little on the sketchy side now. Definitely something that's on my mind.
To satisfy my own curiosity, I did a few virtual dynos while out perfecting my fuel map tonight. Note, my "preferred spot" is not perfectly flat and ramps uphill towards the mid/end of a pull, and I don't think my car has the "normal" CD that virtual dyno calculates with. Big wing, airdam, and all that jazz. So take all numbers with a fistfull of salt.
Low boost(6psi, tapers down to 3psi near redline)
Annnnd "High" boost, 12psi and only dropping a pound or two near redline.
I haven't hit 150mph at RA in a Miata and don't think I want to. Going that fast on a big, open track like Daytona prompted me to put a full cage in my car. And there's a lot more room at Daytona.
You be careful out there.
I was going to suggest he be careful when at home and running the car in the garage for too long.
Even with my car's tailpipe facing the open garage door while Idle tuning I get quite nauseous so now hook this up to the tail pipe and lower the garage door as far as possible:
I was going to suggest he be careful when at home and running the car in the garage for too long.
Garage door is cracked 2-3ft and I have a fan to encourage exhaust gasses out when idling for extended periods. Just can't see it due to the hood/camera angle.
the amount of E85 fumes the exhaust spits out would make it... Difficult to idle for any amount of time with the garage closed.
The good thing about 150 down the back straight at Road Atlanta, it just ends in an interesting ride through a gravel pit. Its only if try to make 10a at 150mph that things get entertaining.
Damn does that go like crazy! Sounds the business to boot.
I agree about the ball-bearing spindown. I can turn off my Precision 6062 equipped E30 at idle. Then grab my laptop, my phone/wallet, roll the windows up, pop the hood, and can still hear the turbo spinning!
Mods, I request a thread title change
from: Wingman's "Low Power Time Attack" Build
to: Wingman's "Low Power" Time Attack Build.
Because yes, this is "Low Power" for everything involved except my transmission.
Yellow: 12PSI, 314whp, 315tq
Blue: 20PSI, 400whp, 370tq
E85, dynojet and all the normal stuff.
Motor and turbo had a ton of room to run yet, but I called it quits once I broke 400whp. I'm honestly not sure how my transmission is alive after 20+ pulls at/near 300ft/lbs. Injectors were at 82% DC at 20PSI with base 50PSI of fuel pressure. Would need 1300cc's or larger to max out the turbo on E85.
I did two street pulls at 400whp then turned the boost back down to 10psi. I'll only turn it up to full bore for special events in an effort to preserve the transmission. Even at full bore I'm limiting a ton of boost down low in an effort to have a prayer of traction.
I'll need a real transmission to feel safe running it consistently at 400whp or higher. I haven't really decided what trans/diff setup will work best for me, but I'm eyeing a few different options, none of which will be in for the 2023 season. I just blew all of next years budget on the turbo setup. For now I'll try to keep Miata 6spds alive with no clutch dumping, launches or other tomfoolery.
Oh, and shoutout to SuperMiata for under rating and over specing their clutches, the website says the organic disk is rated for 290ft/lbs but I've had zero slip at 350ft/lbs+ on the street or dyno. That could change once I slap on 245 A7's and load it up around a track, but for now... 10/10.
10-01-2022, 09:02 AM
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