Premix with blocked OMP, OMP with external reservoir or OEM OMP for trackcar?
#1
Full Member
Thread Starter
Premix with blocked OMP, OMP with external reservoir or OEM OMP for trackcar?
Hi,
I'm planning on using my FD primarily as a trackcar, only some drives to and from the racetrack at cruising speeds and some weekend journeys.
The engine is out at the moment for a rebuild and I had plans to modify the OMP for an external oil reservoir for 2 stroke oil and use fully synthetic for the engine and turbos. I thought that would be the best solution lubrication wise and in terms of carbon buildup.
But now I'm reading more and more that modern synthetics are absolutely fine when burning them in the engine and that some even produce less carbon buildup than the "highly praised" mineral oils or dino oils.
So I'm totally confused now what to do. I want the absolute best solution for my engine, it doesn't matter if its complicated to handle (e.g. frequently filling the external reservoir) or to build.
Maybe here is someone who has inspected different engines from inside that ran different methods and can say which is best?
- Premixing, OMP untouched (What would be the best ratio?)
- Premixing OMP blocked off (What would be the best ratio?)
- OMP modified for external 2 stroke reservoir
- none of the above, just doing it as Mazda intended
I'm planning on using my FD primarily as a trackcar, only some drives to and from the racetrack at cruising speeds and some weekend journeys.
The engine is out at the moment for a rebuild and I had plans to modify the OMP for an external oil reservoir for 2 stroke oil and use fully synthetic for the engine and turbos. I thought that would be the best solution lubrication wise and in terms of carbon buildup.
But now I'm reading more and more that modern synthetics are absolutely fine when burning them in the engine and that some even produce less carbon buildup than the "highly praised" mineral oils or dino oils.
So I'm totally confused now what to do. I want the absolute best solution for my engine, it doesn't matter if its complicated to handle (e.g. frequently filling the external reservoir) or to build.
Maybe here is someone who has inspected different engines from inside that ran different methods and can say which is best?
- Premixing, OMP untouched (What would be the best ratio?)
- Premixing OMP blocked off (What would be the best ratio?)
- OMP modified for external 2 stroke reservoir
- none of the above, just doing it as Mazda intended
#2
It Just Feels Right
iTrader: (11)
IMO "the best" is premixing + external OMP. That said, it may only be marginally better than premixing alone with the stock OMP or even any OMP for that matter.
First, the OMP only drips oil at the nozzle. This doesn't fully spread across the rotor face.
Second, the benefits of an external OMP vs stock are minor IMO. Yes you are not burning cruddy engine oil but is that a big deal, probably not (and more so if you change your oil frequently which you should be doing anyway on a track car). The other touted benefit is you can run synthetic with an external OMP because synthetic doesn't burn. That's pretty much rubbish.
Third, running an external OMP is both complicated and expensive (you need an RA OMP adaptor (if they even make them any more), a Mikuni OMP, and an external tank). And don't forget to keep the tank filled.
All that said, I run an external OMP because it's "the best"
First, the OMP only drips oil at the nozzle. This doesn't fully spread across the rotor face.
Second, the benefits of an external OMP vs stock are minor IMO. Yes you are not burning cruddy engine oil but is that a big deal, probably not (and more so if you change your oil frequently which you should be doing anyway on a track car). The other touted benefit is you can run synthetic with an external OMP because synthetic doesn't burn. That's pretty much rubbish.
Third, running an external OMP is both complicated and expensive (you need an RA OMP adaptor (if they even make them any more), a Mikuni OMP, and an external tank). And don't forget to keep the tank filled.
All that said, I run an external OMP because it's "the best"
Last edited by TomU; 07-25-17 at 09:14 PM.
#4
Full Member
Thread Starter
I would have modified the OMP myself, like one user on here did:
Thread can be found here: https://www.rx7club.com/3rd-generati...ection-585049/
But yeah, since I will change my oil very frequently (With my last track car I changed it yearly or after 2000-3000 miles and I think I will shorten that with the FD) going stock OMP plus premixing should work just fine.
Thread can be found here: https://www.rx7club.com/3rd-generati...ection-585049/
But yeah, since I will change my oil very frequently (With my last track car I changed it yearly or after 2000-3000 miles and I think I will shorten that with the FD) going stock OMP plus premixing should work just fine.
#5
Urban Combat Vet
iTrader: (16)
Just running pre-mix, when injector duty goes to zero, so does your hard seal lubrication. Something that will happen frequently and from relatively high rpm on the track. If you have a PFC and a datalogger it is possible to compensate for that. Not certain about the other standalones.
The OMP is rpm and load dependent.
The OMP is rpm and load dependent.
Trending Topics
#8
endless build
iTrader: (15)
Another thing to add to the "best setup" from the gentleman up top ,
Later model (S8)
Not only came with the new Mikuni OMP
But also , the Holes in the rotor housing a slightly bigger .
Anyhow Mazda don't make the old ones anymore.
AND
The injector nozzles are also slightly bigger than the S6 models.
Later model (S8)
Not only came with the new Mikuni OMP
But also , the Holes in the rotor housing a slightly bigger .
Anyhow Mazda don't make the old ones anymore.
AND
The injector nozzles are also slightly bigger than the S6 models.
#9
Recovering Miataholic
TC-W3 2-Stroke Marine Premix OK?
Our '94 is running TC-W3 premix at 8 oz/tank fill (about 14 gals). This is during initial break-in of a new engine. Does this sound about right? OEM OMP with new lines, street use only. Roughly 100 miles on the engine at the moment.
Type of oil good? Amount about right? Or should I use more oil?
Comments appreciated!
Type of oil good? Amount about right? Or should I use more oil?
Comments appreciated!
#11
rotorhead
iTrader: (3)
Carbon buildup on a race engine? It's not nearly as big of a concern as all the other things like cooling and knock. I wouldn't sweat the details.
^^ I'm going to give a similar answer. It's a new engine. Your OMP is working. If it weren't working, the stock ECU is smart enough to go into limp mode (NO OTHER ECU is as smart as stock for running the OMP). Premix if it gives you peace of mind, but it is totally unnecessary. Your first engine lasted 24ish years and over 100k miles. Don't sweat the details.
i would tell your wife to drive it like a normal car at this point, or maybe be easy until 500 miles if it gives peace of mind. Giving her premix ratio formulas or you filling the fuel for her so it's done "correctly" is a needless hassle.
the stock oil change interval is 5000 miles for light duty use, and you'd be surprised how little oil an engine needs to run... that's why the idiot light only comes on when you are way down. The point is, you're not getting much benefit by doing extra things.
^^ I'm going to give a similar answer. It's a new engine. Your OMP is working. If it weren't working, the stock ECU is smart enough to go into limp mode (NO OTHER ECU is as smart as stock for running the OMP). Premix if it gives you peace of mind, but it is totally unnecessary. Your first engine lasted 24ish years and over 100k miles. Don't sweat the details.
i would tell your wife to drive it like a normal car at this point, or maybe be easy until 500 miles if it gives peace of mind. Giving her premix ratio formulas or you filling the fuel for her so it's done "correctly" is a needless hassle.
the stock oil change interval is 5000 miles for light duty use, and you'd be surprised how little oil an engine needs to run... that's why the idiot light only comes on when you are way down. The point is, you're not getting much benefit by doing extra things.
Last edited by arghx; 07-26-17 at 08:01 PM.
#12
Recovering Miataholic
Comments are indeed appreciated.
Yep, necessary for my peace of mind (I admit to being somewhat OC). Also Yoshiya recommended 2-stroke oil at about this concentration, even over the life of the engine. Although he personally uses engine oil (Castrol GTX 10W-30).
Our fill-ups are almost always close to 14 gallons. Car has never run until dry (20 gallons fuel capacity). I change oil at 3K miles, just from habit.
Premix if it gives you peace of mind, but it is totally unnecessary.
Our fill-ups are almost always close to 14 gallons. Car has never run until dry (20 gallons fuel capacity). I change oil at 3K miles, just from habit.
#14
It Just Feels Right
iTrader: (11)
FWIW, I use Legend ZX-2SR for both pre-mix and OMP
ZX-2SR | Legend Performance Inc.
Last edited by TomU; 07-27-17 at 10:12 AM.
#15
Long time on-looker
iTrader: (33)
I've tracked the same FD engine for 8 years now. Using stock OMP and supplement about 0.5 oz/gal Idemitsu premix when at the race track.
You're going to want to change your oil much more frequently than your past track cars and that will help ensure you're injecting good oil via the OMP. I change my oil every other track event. The car sees only about 10-20% street use.
You're going to want to change your oil much more frequently than your past track cars and that will help ensure you're injecting good oil via the OMP. I change my oil every other track event. The car sees only about 10-20% street use.
#16
Eye In The Sky
iTrader: (2)
Join Date: Feb 2001
Location: In A Disfunctional World
Posts: 7,892
Likes: 0
Received 114 Likes
on
66 Posts
Cam at Pettit Racing has always recommended adding premix to the gas tank even with stock engines with working OMPs. He said it really extends the life of the engine.
For ease of use on a street and track car I suggest my setup: modify the OMP to use an external tank filled with either Idemitsu premix or other racing 2 cycle oil, and fill the tank with premix at a minimum of .5 oz per gallon. This way you can still drive the car on the street without gas tank premix if needed.
For ease of use on a street and track car I suggest my setup: modify the OMP to use an external tank filled with either Idemitsu premix or other racing 2 cycle oil, and fill the tank with premix at a minimum of .5 oz per gallon. This way you can still drive the car on the street without gas tank premix if needed.
#17
Recovering Miataholic
Cam at Pettit Racing has always recommended adding premix to the gas tank even with stock engines with working OMPs. He said it really extends the life of the engine.
#18
Urban Combat Vet
iTrader: (16)
...It's a new engine. Your OMP is working. If it weren't working, the stock ECU is smart enough to go into limp mode (NO OTHER ECU is as smart as stock for running the OMP). Premix if it gives you peace of mind, but it is totally unnecessary. Your first engine lasted 24ish years and over 100k miles. Don't sweat the details.
i would tell your wife to drive it like a normal car at this point, or maybe be easy until 500 miles if it gives peace of mind. Giving her premix ratio formulas or you filling the fuel for her so it's done "correctly" is a needless hassle.
the stock oil change interval is 5000 miles for light duty use, and you'd be surprised how little oil an engine needs to run... that's why the idiot light only comes on when you are way down. The point is, you're not getting much benefit by doing extra things.
i would tell your wife to drive it like a normal car at this point, or maybe be easy until 500 miles if it gives peace of mind. Giving her premix ratio formulas or you filling the fuel for her so it's done "correctly" is a needless hassle.
the stock oil change interval is 5000 miles for light duty use, and you'd be surprised how little oil an engine needs to run... that's why the idiot light only comes on when you are way down. The point is, you're not getting much benefit by doing extra things.
#19
Full Member
Thread Starter
I've tracked the same FD engine for 8 years now. Using stock OMP and supplement about 0.5 oz/gal Idemitsu premix when at the race track.
You're going to want to change your oil much more frequently than your past track cars and that will help ensure you're injecting good oil via the OMP. I change my oil every other track event. The car sees only about 10-20% street use.
You're going to want to change your oil much more frequently than your past track cars and that will help ensure you're injecting good oil via the OMP. I change my oil every other track event. The car sees only about 10-20% street use.
I thought it would be enough to change the oil every 2-3 events so after 4-6 hours of track driving.
#20
Long time on-looker
iTrader: (33)
How long are your track sessions? Mine will only be 1- max. 2 hours of driving, so changing the oil after every event seems a bit like overkill to me. Plus, in the past I've been doing 7 to 10 events a year, so this would be pretty pricey, assuming that I should change the oil filter every time too.
I thought it would be enough to change the oil every 2-3 events so after 4-6 hours of track driving.
I thought it would be enough to change the oil every 2-3 events so after 4-6 hours of track driving.
I run between 20-30 min sessions depending on the group I run with and between 8-15 sessions in an event.
The following users liked this post:
Namxi (08-01-17)
#21
Full Member
Thread Starter
Sorry for the confusion. My statement of "every other event" probably didn't translate well. That means I go 2 events on one oil change. I also go 2 oil changes on one filter since they're relatively short. So 2 track weekends on one oil change (end up adding from cat can loss during) and 4 weekends on a filter. Pretty cheap compared to other consumable costs. With heavy track use you'll find the oil gets so much fuel dilution you shouldn't go further on intervals anyway.
I run between 20-30 min sessions depending on the group I run with and between 8-15 sessions in an event.
I run between 20-30 min sessions depending on the group I run with and between 8-15 sessions in an event.
Wow, thats a lot of track time. How many events do you do over a year? Just curious.