Corten-Miller Rotrex kit (for NC Miata) preliminary results are out!
#1
Corten-Miller Rotrex kit (for NC Miata) preliminary results are out!
I've been waiting for a Rotrex kit for my '13 Miata Club for about 3-4 months now, and it seems results from at least one of the kits is out. I am looking for an FI solution which would be most reliable at the track, and Rotrex kits seem to be very promising since they don't harass the engine much at lower RPMs, and they do promise to provide very linear throttle response and minimal lag, if any, which are both crucial for track duty.
This is from their facebook page.
Both before and after cars seems to have full exhaust and CAI; at least that's what I assumed "breathing mods" meant. They used UK pump gas.
What do you guys think? At least, this graph does not start from an atmospheric RPM :P
Looking forward to seeing what KraftWerks kit makes in comparison to this one.
This is from their facebook page.
Both before and after cars seems to have full exhaust and CAI; at least that's what I assumed "breathing mods" meant. They used UK pump gas.
What do you guys think? At least, this graph does not start from an atmospheric RPM :P
Looking forward to seeing what KraftWerks kit makes in comparison to this one.
#2
And here is a little comparison of C-M and KraftWerks kits I made originally at Miata.net today. Admins, I am hoping that copying a post is allowed; apologies if it's not!
MX-5 Miata Forum - View Single Post - [Supercharging] KraftWerks Rotrex Supercharger / Sneak Peek
--------
I've been comparing KraftWerks and C-M kits, and there are a few issues that pop up in both kits:
KraftWerks:
(1) The oil reservoir seems to be higher than the supercharger. Rotrex now recommends that both the oil cooler and the canister should be below the supercharger's height to avoid possible oil leak from some of the seals:
(2)The air filter location for this kit has always been in question since we saw the first pics. The reasoning given to us is that the intercooler pipes are using the opening by the front of the car, leaving no space for the air filter. C-M's kit doesn't seem to have much longer piping, yet they were able to reserve the front opening for the air filter. Wouldn't this be a better solution? (Brian's car seen below).
Corten-Miller
(1)C-M seems to have placed the MAF right after the air filter, BEFORE the supercharger and the intercooler. I don't think what MAF reads in terms of amount of air, and more importantly the air temp will be exactly same as what enters the engine anymore, since the air charge will have to go through the supercharger and the intercooler first. Kraftwerks has kept the MAF location at right before intake manifold, which I think is the best location.
(2)C-M's intercooler looks substantially bigger to me. I am not sure if this is a good or bad thing, considering it comes before all other radiators (like A/C condenser, coolant radiator, etc.). I don't know full dimensions including thickness, so I might also be wrong.
MX-5 Miata Forum - View Single Post - [Supercharging] KraftWerks Rotrex Supercharger / Sneak Peek
--------
I've been comparing KraftWerks and C-M kits, and there are a few issues that pop up in both kits:
KraftWerks:
(1) The oil reservoir seems to be higher than the supercharger. Rotrex now recommends that both the oil cooler and the canister should be below the supercharger's height to avoid possible oil leak from some of the seals:
(2)The air filter location for this kit has always been in question since we saw the first pics. The reasoning given to us is that the intercooler pipes are using the opening by the front of the car, leaving no space for the air filter. C-M's kit doesn't seem to have much longer piping, yet they were able to reserve the front opening for the air filter. Wouldn't this be a better solution? (Brian's car seen below).
Corten-Miller
(1)C-M seems to have placed the MAF right after the air filter, BEFORE the supercharger and the intercooler. I don't think what MAF reads in terms of amount of air, and more importantly the air temp will be exactly same as what enters the engine anymore, since the air charge will have to go through the supercharger and the intercooler first. Kraftwerks has kept the MAF location at right before intake manifold, which I think is the best location.
(2)C-M's intercooler looks substantially bigger to me. I am not sure if this is a good or bad thing, considering it comes before all other radiators (like A/C condenser, coolant radiator, etc.). I don't know full dimensions including thickness, so I might also be wrong.
#3
Moderator
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,645
Total Cats: 3,009
A MAF after the compressor will not read compressed air volumes correctly, but may read the temperature more accurately. The MAF before the compressor will have the opposite problem. Ideally, one should either separate the two or use a different measuring device (or algorithm) entirely.
#6
Pricing is not yet announced, but historically such kits are priced around $4K with $600 initial pricing discount. That's what I would guess the pricing would be around.
The dyno graph above is said to be at the flywheel. I was very excited thinking it might be at the wheels, but well, I guess it's still not too bad. I wonder how the KraftWerk kit's numbers will turn out now...
The dyno graph above is said to be at the flywheel. I was very excited thinking it might be at the wheels, but well, I guess it's still not too bad. I wonder how the KraftWerk kit's numbers will turn out now...
Last edited by X25; 02-11-2014 at 02:40 PM.
#8
I don't know what C-M uses, but KraftWerks uses C30-84. I don't work for any of these companies, but I want to have a seamless FI solution good for track duty, and these seem to fit the bill. I've suffered quite a bit with turbo kits in my former cars before switching to Corvettes, and I really don't want to go through that again
#9
Elite Member
iTrader: (1)
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 406
A MAF after the compressor will not read compressed air volumes correctly, but may read the temperature more accurately. The MAF before the compressor will have the opposite problem. Ideally, one should either separate the two or use a different measuring device (or algorithm) entirely.
#11
Elite Member
iTrader: (37)
Join Date: Apr 2010
Location: Very NorCal
Posts: 10,441
Total Cats: 1,899
Make sure the company has the product tested and there are a buttload of them on the road before you buy. A "$500 discount" is not enough to get me to effectively "beta test" a $3.5k product for a company.
I'm no stranger to the Rotrex: https://www.miataturbo.net/random-su...th-fail-62346/
#14
If you want reliability my only advice is this: DO NOT BE AN EARLY ADOPTER.
Make sure the company has the product tested and there are a buttload of them on the road before you buy. A "$500 discount" is not enough to get me to effectively "beta test" a $3.5k product for a company.
I'm no stranger to the Rotrex: https://www.miataturbo.net/random-su...th-fail-62346/
Make sure the company has the product tested and there are a buttload of them on the road before you buy. A "$500 discount" is not enough to get me to effectively "beta test" a $3.5k product for a company.
I'm no stranger to the Rotrex: https://www.miataturbo.net/random-su...th-fail-62346/
I have actually read your thread before. I'm not sure if it was fun for you to go through that all, but it was fun to read
#15
Elite Member
iTrader: (1)
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 406
Great, so this means KraftWerks' location is much better. I wonder why C-M would even choose to put the MAF location there. Perhaps they don't know any better? That would put serious doubt in my mind in terms of their credibility. EO2K, there goes your theory of me being a C-M salesman.
If the MAF has a IAT sensor then I would put it downstream so that it can use those readings, but it doesnt have to have an IAT sensor at all. Its measuring the mass airflow and because of gas laws you dont have to know IAT, pressure or volume if you know the mass airflow.
In practice, I think that a "blow through" MAF is better because you dont have to recirculate the bypass/BOV and because you can put the sensor closer to the throttle, decreasing its latency (if it even matters).
What is really important is that the MAF is on a good smooth piece of tubing where there is laminar airflow and that it is properly calibrated in the MAF table. If you have that, the car pretty much tunes itself.
#16
Theoretically, neither is really better than the other.
If the MAF has a IAT sensor then I would put it downstream so that it can use those readings, but it doesnt have to have an IAT sensor at all. Its measuring the mass airflow and because of gas laws you dont have to know IAT, pressure or volume if you know the mass airflow.
In practice, I think that a "blow through" MAF is better because you dont have to recirculate the bypass/BOV and because you can put the sensor closer to the throttle, decreasing its latency (if it even matters).
What is really important is that the MAF is on a good smooth piece of tubing where there is laminar airflow and that it is properly calibrated in the MAF table. If you have that, the car pretty much tunes itself.
If the MAF has a IAT sensor then I would put it downstream so that it can use those readings, but it doesnt have to have an IAT sensor at all. Its measuring the mass airflow and because of gas laws you dont have to know IAT, pressure or volume if you know the mass airflow.
In practice, I think that a "blow through" MAF is better because you dont have to recirculate the bypass/BOV and because you can put the sensor closer to the throttle, decreasing its latency (if it even matters).
What is really important is that the MAF is on a good smooth piece of tubing where there is laminar airflow and that it is properly calibrated in the MAF table. If you have that, the car pretty much tunes itself.
Agreed on the importance of smooth piping before and after the MAF. Being right next to the air filter and the violent air flow (at high speeds) could also become a problem.
OK I'm probably blowing it out of proportion, but you get my idea
#17
I asked C-M about MAF location. Their response:
Thank you for the enquiry. We do not yet have a release date or any pricing information but are working hard to bring it to market ASAP!
As far as MAF placement goes there are pros and cons of both a pull through and blow through arrangement. Our new MAP sensor, unlike the original has an IAT sensor built in so this can now be moved into the inlet manifold to read charge temp and leave the MAF sensor where it is.
As far as MAF placement goes there are pros and cons of both a pull through and blow through arrangement. Our new MAP sensor, unlike the original has an IAT sensor built in so this can now be moved into the inlet manifold to read charge temp and leave the MAF sensor where it is.
Thread
Thread Starter
Forum
Replies
Last Post
Rudes333
Miata parts for sale/trade
17
11-05-2015 01:16 PM