Keith Tanner wrote:
Either our dyno reads low in the sub-200 range (there's some evidence of that, actually) or there's some real fudging out there.
I know you guys apply correction factors, but I still can't help wondering what the mile-high elevation does with your dyno readings vs what those of us experience at low altitudes.
ProDarwin wrote:
Liquidog wrote:
Couldn't agree more, Keith. I feel like hopping up the BP is sort of a vestigial tail for the miata community, at least in terms of N/A power. It's not that useful anymore, there are better ways to build a more powerful miata, and no one really thinks about it too much. People just sort of say "yeah go for the I/H/E/tune and you'll get 150whp from a 1.8" but really, it's the absolute least economical way to go in the long run, if you ever want more than 150whp, and even that 150 is suspect.
I would bet that a good portion building for NA power are doing so because of classing. The 150whp builds align nicely with CSP allowances. There are a LOT of Miatas running CSP.
I wouldn't argue that, but I would say that if you want to run a Miata in CSP, you should go to an event and start asking around about cars for sale. Much cheaper overall, better bang for buck. Trying to bring it back to the engine swap question, the whole reason that the J swap and the ecotec swap are being looked at is bang for buck. Or maybe I'm extrapolating too far and basing this too much on my own thought process. In my mind, non-V8 engine swaps for the Miata are about bang for buck. The hierarchy goes: N/A power (bad value), FI power (good value depending on build, almost always better value than N/A power), and V8 swaps (expensive but tremendous value in terms of huge reliable power.) Other swaps have always been the red-headed stepchild in the family. It would be cool if the J engine swap or GM LE5 could occupy the same level in that hierarchy that FI does. I don't really want a turbo car, I want N/A characteristics. Of course the devil's in the details with the new swaps.
nderwater wrote:
Keith Tanner wrote:
Either our dyno reads low in the sub-200 range (there's some evidence of that, actually) or there's some real fudging out there.
I know you guys apply correction factors, but I still can't help wondering what the mile-high elevation does with your dyno readings vs what those of us experience at low altitudes.
Naturally aspirated, the correction factors have shown themselves to be pretty good. Even compared to other high altitude dynos, though - I've seen my 148 rwhp engine run with others that were tested considerably higher, even at altitude. It's interesting.
We've had top-level CSP cars on our dyno. Man, if you want to swim in that pool, you have to be prepared to put in some serious time. A swap would be easier than chasing that last 10%.
It's going to be interesting to see what happens over the next few years. I think there are some good options being investigated and some dead ends. Time will tell, but not right away.
Could make for a very interesting GRM comparison once the various players mature into legit swaps. I'll be there
I think your Rototest spit out some really high numbers, but no idea how it handled low power cars. And of course, know nothing about your current unit.
I my be giving the 150whp BP a shot soon. If so, i'll document it.
Our Dynojet read high, our Rototest read high, our new one must read high too. Because we own it. We both know your car had some problems when it was at our shop.
I think the Rototest was skewed - low at low power, high-ish at high power. We're still working on the new one, learning how to best use the tool. You can't make customers happy with dyno testing, we're more interested in repeatability for testing purposes.
Keith Tanner wrote:
Our Dynojet read high, our Rototest read high, our new one must read high too. Because we own it. We both know your car had some problems when it was at our shop.
I think the Rototest was skewed - low at low power, high-ish at high power. We're still working on the new one, learning how to best use the tool. You can't make customers happy with dyno testing, we're more interested in repeatability for testing purposes.
Well yeah, but it still spat out 245whp on the Rototest. Doesn't bother me, it's just numbers. I know the dyno i had it on later is notorious for reading low. (I somewhat doubt an MSM actually making 194whp would run 12.7@108 mph.) But this is why numbers are just numbers. I'm with you, dynos are a tool, not a race.
I still think a legit 150whp can be had fairly easily.
Jaynen
Dork
1/13/15 11:26 p.m.
I was just thinking, I wonder if you can retain the cylinder deactivation if you do this swap as an option. Get even better mpgs putting it into a lighter car
unk577
HalfDork
1/25/15 8:27 p.m.
Think about this mounting solution. That's a lot of stress on the adaptor and motormounts
666csi
New Reader
1/26/15 12:31 a.m.
The sub frame & tabs welded to it look like the minimum required, but the poly mounts themselves and that monster adapter plate could probably hold up the whole bloody car!
NOHOME
UltraDork
1/26/15 10:05 a.m.
unk577 wrote:
Think about this mounting solution. That's a lot of stress on the adaptor and motormounts
I thought this was a cool swap until I saw that
I see what they are doing by using the Miata PPF as a huge lever to offset the weight of the engine. In effect the two engine mount tabs would see minimal torsional loads due to the long lever length and the weight of the engine SHOULD be trivial mounted to such a solid face on the backside of the engine. But I would need to be convinced. The gearbox in particular would be carrying a strong bending lever from where the PPF mounts up to the face of the mount. I have a feeling the gearbox designer did not factor that in to the equation when doodling up the transmission case.
I am not a structural engineer, but I can't see that working. What I see does not give me confidence that any of the rest of the kit is going to be better designed.
Look at it this way - if you need more ground clearance under the oil pan, you can just push down hard on the shifter
kb58
Dork
1/26/15 2:58 p.m.
Dynos are for comparative tuning, before/after sort of tunes.
I had my car dynoed on a well-known DynaPack dyno and was very happy with the results. Some months later I had the same car on a drum-type dyno and it read a good 20% (no kidding) lower. Asking around, apparently DynaPack dynos - especially the one I used - are known to be absurdly optimistic. That said - it doesn't matter.
If you go in with X hp and leave with X + Y power, the results are the same regardless of dyno type. However, I admit it IS a little misrepresentative - like finding out that your date was wearing a miracle bra*, but I digress.
- I'm going to develop "Miracle Briefs" to make guys look like they're packing... a lot. Seems only fair. Now, where were we?
Keith Tanner wrote:
Look at it this way - if you need more ground clearance under the oil pan, you can just push down hard on the shifter
Yeah, like starter clearance? Is that what's bottom and center?
Vigo
PowerDork
1/27/15 5:12 p.m.
I think it will work fine, but i'm the kind of person that will build something even worse for 1/10th the price and be happy. For whatever reason i've done a lot of experimentation with how 'crappily' you can build something and still have it work so i think i just have an innate sense of how badly you can build something and get away with it.
On the other hand, i've personally seen a miata get mad air bashing over a berm after sliding off a road course. Maybe that would break it. If you're trying to build stupid-proof, maybe this wouldnt be my first choice, but in any event i doubt this mounting would be THE smoking gun if you managed to break something. It would probably be something like you accidentally went through a ditch at high speed and because of defensive blame displacement you are more annoyed at your broken trans case then you are at yourself for crashing your car.
wheelsmithy wrote:
Keith Tanner wrote:
Look at it this way - if you need more ground clearance under the oil pan, you can just push down hard on the shifter
Yeah, like starter clearance? Is that what's bottom and center?
Special sacrificial starter for racing.
Once the motor is running, first bump sheds the starter off to save weight for the race.
Since this thread has also talked about the Ecotec swap I got them to reply on facebook and they said their 200whp dyno post was only with some head work
"MT Motorsport The 200whp had nothing but a lightly ported cylinder head. Everything else was completely stock. Weight between motors is approx the same. Going on scales soon."
I was happy to see the vtec Miata in the new issue of GRM. In the article you say: "We ran a teaser in the magazine, and our message board erupted. Tell us more."
Unfortunately, there's not much in the article that I hadn't gleaned from reading this thread and visiting the vendor's web site. Pretty pictures. Breezy content.
Some questions that didn't get answered: How's the build quality of the kit? Fit, finish, weld quality, hood clearance? How tight is the front of the engine bay? This build uses an aftermarket ECU. How was the tune? How was the drivability?
How's well does the supplied exhaust fit? How loud is supplied exhaust? How much time did you spend in the car? What did the temp gauge say? Overall solidity of the install? Squeaks? rattles? What, if anything else did it need?
Jaynen
Dork
2/13/15 10:11 a.m.
The kit is not done so I think all that is not data that we have yet
How about an all-in price for the swap as-built for MiniTec's NA and NB demo cars?
Jaynen wrote:
The kit is not done so I think all that is not data that we have yet
If you go to the vendor's web site, There's an "add to cart" button. It's for sale.
Hard hitting evaluation like that isn't GRM's strong point, Lux. Some data on things like ground clearance would be pretty useful, though. How does it change relative to stock?
Keith Tanner wrote:
Hard hitting evaluation like that isn't GRM's strong point, Lux.
I don't need "hard hitting". But, it would be nice to get some info that can start to inform a decision to build-it-or-not. To move beyond the brochure.
You could expect some info on fit and clearance, but not on temperature gauge misbehavior, squeaks, rattles or ECU tunung.
Jaynen
Dork
2/13/15 11:15 a.m.
I saw the add to cart also but also noted no "hey its done" or anything like that updated on their facebook or website. Which if the product is complete would seem really weird.