91 Octane power limitation?

[mx54life]

Would a 275 HP be a realistic claim on a turbocharged 1.8 NB using 91 octane?

[horribleR]

Yes.

[BoBo]

It can be done! I had a couple of Mr2's pushing 350-455 at the wheels. A miata can do it. Cooling and reliability is the main issue. My old 1.6 miata had about 250hp, I quickly sold that car after buying a new diff & tranny hehehe. Next time I go 250hp, I will make sure to have Quaife parts.

[mx54life]

Thanks Guys.


BoBo that is a good warning........I might just as well stay on the safe side (200 HP) lol.

[Slampen]

I will make sure to have Quaife parts.

The NA8 diff should handle what stock internals manage to make. Quaife is cool though.

[BoBo]

Thanks Guys.


BoBo that is a good warning........I might just as well stay on the safe side (200 HP) lol.

OP, For me, 160-200hp is like the sweet spot. Your car is already supercharged right? You should be set. Right now I got a 96, at the moment I'm not sure what my plans are with the car, but I do know it could use another 50hp. I have to upgrade my radiator, last time I took my car at the track it overheated on me. It was a hot summer like triple digits.

The NA8 diff should handle what stock internals manage to make. Quaife is cool though.

^Yup the 1.8 NA's have stronger diffs. That's another reason why I sold my 92.

[mx54life]

[QUOTE=BoBo;183482]OP, For me, 160-200hp is like the sweet spot. Your car is already supercharged right? You should be set. Right now I got a 96, at the moment I'm not sure what my plans are with the car, but I do know it could use another 50hp. I have to upgrade my radiator, last time I took my car at the track it overheated on me. It was a hot summer like triple digits.


I am actually upgrading my 94's JRSC M45 to an FFS TVS-900. But I am also about to pick up a supercharged NB till this 1999 NB with FM1 Carb Legal Turbo and an FM built 1.9 liter motor showed up for sale. The later boast a claimed 275 HP which brings me to be a bit wary altho' it looks like it is a well sorted out car. I am really looking at this carefully as I already have a SC car so a turbocharged Miata is very welcome. I am just sold with the reliability of a SC.

[BoBo]

FM makes great kits! But I don't think they are CARB legal, I do know they pass the sniffer though. Speaking of an FM built motor, I would love to have one. However, I ended up buying other things at the time. The supercharged NB sounds promising. What kind of blower? MP62? FFS?

[— kung fu jesus —]

If you're sold on the reliability, I would take the turbo over the FFS S/C.

[mx54life]

FM makes great kits! But I don't think they are CARB legal, I do know they pass the sniffer though. Speaking of an FM built motor, I would love to have one. However, I ended up buying other things at the time. The supercharged NB sounds promising. What kind of blower? MP62? FFS?

It's the FM1 for 1999 cars "only" which is basically a BEGI kit. This is the one that Corky designed before the two companies split from what I gathered. This particular one seems to be well thought out and installed. Parts wise this has a boat load of valuable items which may or may not be a failure point but then it is a Miata not a Porsche. Having said that, a 275 HP Miata if it is as claimed then it will give some Porsche some grief. On the other hand the SC'd NB has a FSS and well sorted likewise. Both cars have been boosted w/o known issues for the last 6+ years but are really weekend cars so to speak. They are also 2K $$$$ apart. Investment wise the SC'd NB has some meat left in the bone but then again I am looking to keep one.

If you're sold on the reliability, I would take the turbo over the FFS S/C.

So the FM1 kit is more reliable than the FFS? I read the ARB EO on both applications and if I am understanding them right the FM1 has more possible/future restrictions than the FFS altho' both are limited to 10 psi to be Carb legal. And if that is strictly the basis, then FFS edges at around 200 WHP. But above 10 PSI it seems that the Turbo has easier flexibility. I am new to this but I am beginning to feel that it all comes down to engine management and/or kit component design. Either of this two kits have to be piggy back to the OEM ECU to be Carb Legal thus the question is which one is more reliable, the FM Links or the Pro Cards? Flying Miata has moved on to Voodoo or Hydra and BEGI has ventured to MS or Exede while FFS still maintains Pro Cards. So base on these situations I am made to think and believe that FFS as it may be hard to accept has timely hit the "sweet spot" (200WHP) and had the ARB's blessings and now time has proven its durability and simplistic design. Now apples to apples, at Miata's OEM component levels IMHO both kits are probably a toss up what will happen after this will be highly dependent on several factors i.e. Preparation, Installation and Maintenance. Depending on the power goal (if one has in mind) all of these three components multiplies cumulatively. With these two kits I am afraid that the FM1 seems to be the step child as FM does not make them no longer and BEGI did not make them neither but as far as ARB is concern they are Corky's while FFS still maintains one happy family. Please school me more I want to spend my wife's blessing wisely LOL also sorry to be so specific with these companies but really if they play we pay..............

[BoBo]

It's the FM1 for 1999 cars "only" which is basically a BEGI kit. This is the one that Corky designed before the two companies split from what I gathered. This particular one seems to be well thought out and installed. Parts wise this has a boat load of valuable items which may or may not be a failure point but then it is a Miata not a Porsche. Having said that, a 275 HP Miata if it is as claimed then it will give some Porsche some grief. On the other hand the SC'd NB has a FSS and well sorted likewise. Both cars have been boosted w/o known issues for the last 6+ years but are really weekend cars so to speak. They are also 2K $$$$ apart. Investment wise the SC'd NB has some meat left in the bone but then again I am looking to keep one.

Porsche definitely have issues with the earlier models like the 986/996 engines. The IMS bearing on those models tend to self destruct. However, there are aftermarket parts that will fix the problem easy.

That's right! Back then it was a Bellengineering kit. I like their CARB legal turbo's, especially the S3. Both car's you mentioned seemed to be well set, so I'm not gonna pick a side. I had two supercharged cars and 3 turboe'd cars if I remember, and both setup have their ups and downs. Post a pic if you can.

[— kung fu jesus —]

So, the FFS is a bear to work on being a cold side. The FM/Bell kit is going to have better customer support and availability for replacement parts and upgrades.

I think, too, that you are passing CARB every other year. If you wanted to change tunes from extra mods, it is far easier with a programmable piggyback than a pre-programmed card. With the FFS, you may run into more heat issues then with a turbo because of the configuration. FFS uses a fifth injector or ethanol cooling IIRC. That is a far less reliable system than a/a cooling of the intake charge.

I think, too, trying to perform maintenance to other systems on the car, like fueling, a/c, and emissions would be considerably more difficult.

If you want Porsche performance, buy a Porsche. 996/7 pricing is very good and the IMS retrofit/repair is not too much if you perform it before it becomes an issue.

[mx54life]

So, the FFS is a bear to work on being a cold side. The FM/Bell kit is going to have better customer support and availability for replacement parts and upgrades.

I think, too, that you are passing CARB every other year. If you wanted to change tunes from extra mods, it is far easier with a programmable piggyback than a pre-programmed card. With the FFS, you may run into more heat issues then with a turbo because of the configuration. FFS uses a fifth injector or ethanol cooling IIRC. That is a far less reliable system than a/a cooling of the intake charge.

I think, too, trying to perform maintenance to other systems on the car, like fueling, a/c, and emissions would be considerably more difficult.

If you want Porsche performance, buy a Porsche. 996/7 pricing is very good and the IMS retrofit/repair is not too much if you perform it before it becomes an issue.

First up is thanks for all the time you spend with us. I really appreciate your wisdom. Such made me learn more about my passion. More power to you KFJ. Now let me squeeze more on these power house option. Yes the FFS is a bear to work on I am installing one right now on my 94, but past the intake manifold nothing else to wrestle with. Funny you mention about customer report, from my own personal experience FM's support is limited to their "own" customer only at least that's how they made me feel. Emails were returned after a weeks time, they mark your calls and unless you're a first time homebuyer so to speak, there is an unwelcoming tone on the other end of the call. May be just because they don't know me yet. Now FFS is totally the opposite. The company is "Tom". He makes you feel he supports you but the bottom line is it's not really you it's his product. So for as long as you support FFS in any way shape or form, you got Tom on a leash. I guess the business approach of the these two companies are uniquely different but in the end they will equate as for FM you need to pay to get support (they actually have a "fee" for unlimited support lol). Well that make sense if you really come to think of it. FFS on the other hand will give you objective and proven support for free as long as it is about FFS. And the response time of Tom is unequal at least at the moment. Availability of replacement parts are probably equal especially on the kit specific parts. Now regarding upgrade, this will be relative to the question on how far you want to go. This is also where FFS and FM will vary greatly. In my observation, FFS will only objectively support as far as the OEM parts can handle. Most argument I've read is on issues where people wants more power than their budget can handle. Meaning you need twice the money you just spent on a power upgrade kit to make your engine viable for the unlimited power all of us crave for. FM seems to have the support for this but yet again it will cost you twice the money you spent on your turbo kit.

FM's kit is easer to tweak yes, but the cost of a slight mistake is high. So personally I think that is a scary advantage. Heat issue is a theory for both upgrades and proper cooling is a must and has been address effectively by many a users. The FFS design (staying within their limitations) has been proven for about what 10 year now? A personal friend has an FFS in his 92 NA for about 7 years and it is a daily car w/o any issues on the kit. Performing maintenance on both kits have their own challenges.

My own observations too is that there are more for sale turbo cars than supercharge cars. Understandably they are not FM kit cars but they are not FFS cars either. And the resale value of an FFS kit seems to hold better and doesn't seem to last long in the classifieds.

You are right about the Porsche's that is my ultimate car.................one of these up coming holidays................more power to you sir!

[— kung fu jesus —]

Thanks for the input. I have heard FMs support was falling off. Didn't know it was that bad. Shame.

I have been considering FI again, I am eyeing a Rotrex for my 1.6.

[mx54life]

Thanks for the input. I have heard FMs support was falling off. Didn't know it was that bad. Shame.

I have been considering FI again, I am eyeing a Rotrex for my 1.6.

They must have been burn several times already that is why but they should reevaluate their goals. As Tom said there are over a million NA's and NB's the potential for business is very much alive. FFS kit remains with a target advertised power of 200 WHP to date and Tom flaunts his car with over 270 WHP. Same engine management and same components. Major complaints remains the same and that is customers can't get what they think they want but they do get what they paid for. That is the kit is rock solid as advertised. No none fitting parts. Now I somehow understands why Tom is so close minded with things other than his, it's because the damn kit works. In my friend's case it made his Miata a true all around sports car. He told me just this year that it really took a good 4 years before he developed the right driving skills for his SC'd Miata. LOL a 60 yr old who knows how to drift and do donuts in an empty parking lot after a rainfall.

Rotrex is a very good contender or option, several companies I think is having good success. From what I have learned here in this forum and from people like you KFJ is that "the sum of all its part" is the key. Well engineered components, well thought out and researched fuel management and simple maintenance are a must. So a Miata that has double its factory WHP in the hands of skilled driver is a beast to beat.The inherent lightness of the almighty Miata plus a reliable FI is a blessing.............