so those of you with a supercharged miata...
 

would you do it again or would you go turbo?

yeah yeah can get a bit more out of a turbo, but for those just wanting a fun daily is the extra 20 horsepower really worth it?

I have both and still prefer the turbo. Properly sized, turbo lag is not an issue and I like the power delivery. Moreover, I believe the turbo is a simpler and more reliable form of FI.

i actually kind of enjoy a bit of lag. i like the rubber band acceleration feeling associated with something that doesn't make boost until a bit higher in the rev range. yeah, i know that should probably put me in the turbo camp, but i've had 3 turbo cars so maybe i just want something a little different with the ability to keep my forced induction.

no doubt turbos are more efficient (that's just science, not opinion) as far as power production goes. reliability i think would have to come down to the build of either engine or setup i suppose.

i must say the crank problems on early cars do make me a little leery of a supercharger. overstated or not, it's a shitty problem to have to worry about.

20 hp! i daily drive my 250+ rwhp car. it's pretty solid. and lots of fun.

but have you ever driven a supercharged car? i haven't...i'm just curios as to why someone would go that route.

at this point if i was given a miata right now along with enough cash to add my perfect forced induction system i'd put on a supercharger. partly because there are tons of turbo cars going around and i guess partly to be different. that and with a supercharger i can still add some of the fun n/a power modifiers.

and can you honestly say a 230 or 240 hp car would be less fun? i see both sides here, i'm just playing devils advocate.

Ignoring all other factors, that a turbo serves as a muffler is one reason I'm so fond of them. My Miata, with only the turbine and one straight-through muffler acting to diffuse sound waves, is quieter than a lot of n/a cars which are much slower. The same exhaust on a supercharger would be near deafening!

that is something i have considered. i love the sound of a borla on these cars, but i figure when the time comes i can always tinker with the exhaust if it's a bit too loud.

My supercharged car is quieter than when it was N/A. I like the linear power delivery of the S/C.... makes it feel like a bigger engine across the board. My setup is 185 rwhp at about 6lbs of boost. No problems after 2 1/2 years and 15k miles.

I don't think I would switch my SC... would I do the purchase differently, probably. If still hotside, would have bought TDR (no it wasn't available when I bought my kit). Definately something 6-rib....

Would have probably gone with an MS as well.... 4 years makes a big changes in support, etc....

Might go coldside, but I'm not sure.

Driven a few turbos, and some of them, depending on how they spool are great to drive..... Make all those cool bov noises too.....

But I'm happy with what I gots.......

Dave,

I have both, and like both, so I'm not much help....

add a ls1 miata and your set!

GF already wants to get another lift (this one a 4 poster) for more storage, It was HER idea, couldn't believe it... Oh wait it's my money- why wouldn't she want to spend it... Damn the women that don't work and and damn the men even more for taking them in...

LS1...mmm...

I took rides in turbo and supercharged cars and drove both. My favourite was a nicely sorted FMII in a NB. But I went supercharged because I don't like the looks of all that heat blanket and shields that seem to end up filling the space over the exhaust.

I'd go turbo next time, but only because I've already had a charger, not because I don't like anything about it.

which would you prefer as a daily then?

I much prefer the turbo, I built my 'kit' four or five years ago, and it has never left me stranded... The turbo is pretty small but I get good mileage, there's plenty of power when I need to pass or play. It sounds cool, even with the Recirc BOV.

I originally bought the S/C one with plans to twincharge (I built a manifold, have a couple of extra turbo's kickin around and all the hardware) But my kids seem to take up more time than I have right now.

I will add I drive the S/C daily, and she drives the Turbo. I had some S/C issues w/ the original 4 rib belt setup, a few hours and some re-engineering fixed that. The S/C does 'go into boost' pretty early but the car doesn't really go any faster, Miata's don't make enough power down low til the cams wake up. The S/C has the MS, and I like playing with that.

Both of us think the turbo car is quicker, but it maybe just the 'rush' of torque the turbo hits you with over the gradual feeling of the S/C power delivery. One thing I have noticed, I frequent a two lane road where passing is only available in a few spots, the turbo car delivers it's power to the wheels much quicker than the S/C (and results in a lot quicker pass time)

Neither car has more than 200HP, Neither the S/C or Turbo are capable of it (even at 12psi)...

I like the potential of the Turbo cars more, but I have found on track for the 150-190 HP range I like the S/C more. The linear deliver of the power makes throttle moderation easier exiting out of the corner.

I'm going to turbo my miata because I've never been impressed w/ S/C miatas and I just enjoy turbos (never actually driven a turbo miata, ridden in a few...driven 3-4 S/C ones)

But I'm going to try and custom SC a 2.0 ABA hybrid motor in a GTI once I sell my 16v GTI as a daily...

well if your going to do that you could just drop a g60 in the gti and call it a day.


i'm really curious to hear how opinions would change if more people had supercharged cars with a bit more power. something with maybe 10 or 15 horsepower less than a well-suited turbo car. i need to get my hands on a miata followed shortly by the money to supercharge it.

I'll keep you updated. My goal is 215rwhp with my mp62.

please do. that's around what i'd like to get out of a supercharged car.

I can't find my gtech right now, but before I switch pulleys out I want to get an approximate 1/4 and horsepower rating with the current set up. In the next month it should be pretty much the same + intercooler and new clutch. (currently at 5psi) I really think that with the right tune I could hit 165 at the wheels. With my bigger pulley, and the intercooler, I would like to be at 200. Some tuning, maybe a few random things (perhaps a bigger pulley maybe) and I should be able to hit my goal pretty easily. The thing I have really enjoyed about the super charger is the bigger engine feeling that it gives you. My MP62 puts torque out at every rpm level. It does not matter which rpm I am at, I still have 5+ psi when I step on the gas. It's really wonderful. I'll keep you posted. If you are curious and I haven't been on in a while, just bump me with at PM.

Kevin B (I can't remember his nick on here) has a setup very similar to yours with 212 ish at the wheels. You may want to talk to him.

212 with my current set up? Or the set up I'm going for?

The setup your going for. He has worked out a lot of the kinks.

Did he fix the a/c issue?

I'd go for exactly the same kit (MP62 hotside 125/65, TDR copy IC, WI).

If i did it again i wouldn't bother with the EMU though i'd go for the Adaptronic instead.
I'd also not bother with smaller crank pulleys, 125/65 is minimum i'd go for.

I'm chuffed to bollox with my SC, 3 years on and it's been great.
Had a couple of problems with the crank pulley bolts snapping but both were my fault.


Cheers
Mark

Yes, but I have no idea how.

please ask. i'm in an epic fail right now.

So I just finished my Jackson Racing Supercharger installation last night on my 92 Brilliant black special edition. I decided to go supercharger because I wanted to do something different. I have had three turbo miatas, my last one being a 10 psi greddy setup that I was very pleased with. To be honest I was under the impression that a supercharger would be less invasive and would require less molestation under the hood. After installing the setup I would say that the supercharger actually involves more disruption of under the hood systems than a turbo install does. As for power, I was disappointed. I thought that the supercharger would be better having a more broad power band, but actually find myself really missing the sling shot feeling you get when the the turbo hits full boost. I haven't installed my boost gauge yet, so don't know how much boost I am running, but the setup I have is just the basic jackson racing kit. I bought it used on ebay for $1265 shipped(about the same price as a new greddy kit). After having this setup I would definately advise anyone to go turbo over supercharger. The turbo is much easier and cheaper to modify. In order to get more power out of my supercharger kit I have to get a big boost kit. Unless anyone knows where I can source a pulley that would be the same size as the one that comes in the big boost kit, I believe it is a 62.5mm. Otherwise I will just wait to find a used big boost kit. I already have the larger fuel pump, larger injectors and tuneable fuel management. It is also much easier to find a intercooler kit for the turbo kit. I still do not regret doing the supercharger. I consider it a learning experience and enjoyed the installation as I am sure I will enjoy figuring out ways to modify the system. I should not that I also have the goodwin racing roadster sport exhaust on the car and a ETD racing polished stainless header which I installed before doing the supercharger. I felt that the header gave a good increase in power and was $100 well spent. I also put on a cheap($65) polished stainiless radiator air diversion panel, which I would say looks nice, but fitment was poor. So overall my opinion on the supercharger is this: At $2400, its not even close to being worth it. At $1200 I'd probably still order a new greddy kit instead.

when I decided to go the sc route, I knew I would be sacrificing power compared to a turbo system with the same level of work and $.

I was hoping I could achieve the same level of power most turbos attain, and still get the instant on power that is an advantage for the tighter autocross courses that are run up here in Canada.

I'm not there yet, but am still happy with my choice.

So you're running 5psi on a small blower and you are complaining about it not being as fast as your turbos? I mean, if you just finished the install do you think you are being a little bit hard on your choice? You complain about the "slingshot" feeling or rather the lack there of with a supercharger. I guess I understand what you are saying, but there is no slingshot feeling on a motorcycle, and that does a 1/4 mile in about 10 seconds. I guess its slow though to the mighty turbo that you have, but weren't happy with, because you wanted to get a supercharger. :bowrofl: I guess to each their own. I would rather GO fast than just FEEL like I'm going faster. I can be cruising on the highway at 80mph now in 5th gear, tap the gas and watch the boost gauge instantly hit 6psi, and hit 100mph in just a couple of seconds. And thats just with a small ass pulley. Thats not even with the set up that I'm going for! My car with a small 5psi pulley feels like my bmw does with 160 at the wheels. It doesn't feel like anything crazy is going on, it simply feels like a much large motor in my car now.

I don't want to sound holier than thou, but it doesn't seem like it is that difficult to get a supercharger to put out close to a turbo's output... SOT has a 150mm pulley, and that combined with the 62.5mm crank pulley should be well over 14psi on the average set up. If you have that on the mp62 it would most likely be in the neighborhood of 240rwhp. Maybe more if the car could handle it. I really don't see any cars reliably putting out anymore than 240rwhp, so if it's going to be turbo or supercharged, whats the difference? Straight line goes to the turbo, and for something tighter like an autocross track, the supercharger has the advantage. Am I missing something?

That would be me. Hi guys, Kevin B here. I'm more of a lurker kind of guy. Marty emailed me this link.

I'm running a MP62 Hotside I got a couple of years ago from BRP. It's installed in a '93 Miata with 1.8 engine, harness, ECU and brakes. It's got an '86-88 NA RX-7 LSD with a 3.9 ring and pinion.

A 37mm Koyo radiator provides water cooling with a custom remote oil filter and oil cooler installation. To get adequate air to heat exchangers, I've cut a couple of 2.5 X 8 inch or so holes in the front bumper, above the plastic impact absorber. I've also vented the hood significantly.

The stock injectors are controlled by the ELF piggy back that came with the BRP kit. I'm pulling timing with a Bipes unit to avoid knock.

It's intercooled with an AAIC system based on the BRP NB kit. The guy that designed/supplied it to BRP doesn't live too far from me. He felt sorry for me when I started asking around for NA solutions and helped me tweak it for a NA Miata. You've got to have the intercooler to make higher power levels. I think I was 160-170 RWHP pre AAIC. Keith Tanner suggested to me a few weeks ago to ditch the intercooler and go water injection. I'll have to sit on the fence for that one a while.

When I dyno'd the car last spring, it was with a 60mm nose pulley and 100mm crank pulley. It made 201 RWHP with about 175 ft-lbs of torque. The cool thing was that the torque was there through the whole RPM range. It jumped right up to 175 at the beginning and flat lined across. At the dyno, the guy running it said my injectors were starting to lean out at the end of the pull, so I added a 550cc 5th injector with a Split Second controller. It now runs a bit rich, but I'm willing to accept that over knocking the motor apart.

I recently spun the crank bolt out while on track, which buggered up the crank. I now have a donor motor for a high HP build. The goal is for 300+RWHP. I will get rid of piggy backs for a replacement ECU - either MegaSquirt or an AEM unit recommended by a friend.

Last year, I had temperature issues on +90 deg days. I never popped the head gasket, but had to drive by the T-stat temps.
With the replacement motor I just installed, I did a coolant reroute. I got most of the inspiration/ideas from this site. :bigtu:We'll find out next week how well it works with 3 days at Carolina Motorsports Park. If that track doesn't kill your car, then it's pretty tough.

Agent, to answer your AC question - I'm not sure I can help you much. My car is an SM2 prepared track dog. In preparing it, I did an AC & PS delete. You won't be able to run AC with my set up, it's too tight. If you get a Track Dog Racing AAIC, you'll be able to keep the AC, but it will require a significant reduction in the strength of your core support - you have to cut it. I personally found that to be objectionable. I recently read where Flyin Miata is going to/has upgraded their AAIC to be compatible with the Supercharger kit they now sell - which is the old BRP kit. I'd bet they make sure AC can be retained.

I like the SC application for the track due to its simplicity. Blower + belt = Power! The trick is picking the right components: MP62 blower, 6 rib belts for starters. The power's always there, but comes on without a sudden overload - great for digging out of corners at the track - doesn't suddenly unsettle the car's balance. Recently, I've bumped the crank pulley up to a 110mm. Not sure what boost this resulted in - too busy too look. I can really feel the difference digging out of T1 at VIR. I have to worry about the speed making my exit radius too large and running off at exit. Uh Marty - I knocked another second off my VIR Full time over Mem Day(down to 2:20's). :cool:

A friend of mine with a stock C5 Corvette could never pass me until he hit 4th gear. I've never driven a turbo car and this one is my first FI. The only turbo cars I've driven around have been 944's and RX-7's. Most 944's try to drag me on straight aways. After the first try, they pull over next time I get behind them. The other week I was running with a Turbo'd 2nd Gen RX-7(Daniel Clark's Scud Mobile). He was a little quicker than me on the back straight. He says he has to time when he gives the car gas in anticipation to when the car actually delivers. With my SC'd car, it's there for the asking.

Oh yeah, did I mention the car is an absolute blast to drive?

KB - aka rrroadster

Kevin, thanks for the response. I have the same kit that you have. Did the 60mm crank pulley come with your kit or did you purchase that one separate? My goal is to be just under 215 at the rear wheels. Do you think thats a pretty safe power rating to be at? Take it easy.

I acquired the 60mm pulley in the classifieds. The BRP kit came with a 65/95 combo. Anything smaller than a 60mm nose pulley and you'll start experiencing belt slip.

With a 60/100 combo and the right tuning you should be able to make 200RWHP like I did. I may be able to dyno my 60/110 combo this weekend. A 126/65 ratio is 1.938, 110/60 is 1.833 so I'm wondering how close to 225 I am. By setting up a ratio between last years numbers (200/1.666) and my current pulley ratio of 1.833, I get 220. We'll see.

From what I've always been told/read, 235 is the ceiling for a stock engine. I'd be real confident in 225 RWHP with the approriate cooling, both engine air and coolant.

My goal for next year is to get a built motor in the car and work up to 300+RWHP. I want to pull Corvettes! :firedevil

Oh yeah, when you hit the new speeds available to you, be prepared to pony up for brakes! I need to bad. Braking down hard from 126-129 mph can get real dicey. There have been a couple of occasions where all I cared about was keeping it straight and on the tarmac...and I'm on 1.8L brakes. Once I started braking on track left and ended up track right before the turn. I was just along for the ride on that one. Backing up the braking zone solved the dancing, but I know it's costing me in lap times. I'm going to try some brake ducting for next weekend, but I think it'll end up being just a band aid.

KB

My 2 cents. If you are going for more than 225 hp then get a turbo and be done with it. If you are sure that you will be happy with 200-225 then a SC is a real contender. I'm at 12psi (went down 1lb when I put in 9:1 pistons) and around 205-210 whp. Unlike the hotside guys I'm not running an intercooler, but have a 440 cc/min 5th injector and a timing card. IMO putting a cheapo m45 kit and then expecting to put the money in on the backside for Engine management, cooling etc. and hoping to get anything near an MP62 is climbing a steeeep slope. You might get there, but you'll be too worn out to enjoy the view. You will have a finicky, high strung system.

I walked a Mustang GT this morning on the way to work. I could not walk a Vette. Oh well. I knew this going in so I'm happy in my niche.

Your talking purely about M45's right?

Mp62's will happily put out 240bhp all day every day (mine should be between 220-240bhp).

You can get more out of a MP62 300rwhp has been done a few times, but then SC reliability starts to become a problem.

The thing i can't understand is why most SC users don't use better fuel/ignition management, theres very few SC owners running a full standalone.

A hotside will let you run more boost, with the IC.... safely. I've been in a 240 hp SC'd car, and it was wicked.... Been in a high turbo car too.... both good, just different.

If your goals are 200+ personally, I don't think a CS is necessarily the best way to start, only because of the lack of "easy" cooling. That said, I've driven a CS, and for low boost, it's lovely. But higher, deal with the throttle volume for the hotside.

Dave,

I can't see any point in a coldside at all.

Yup, I was talking about M45's. I am also running 240bhp (210whp) no issues. Not many people are getting much more than that. The guy from Colorodo who has 250hp in his signature is actually running around 210 at sea level. Father Leadfoot is running some nice numbers on his twinscrew, but I guarantee it is not as trouble free or smooth driving as a 200-210 WHP (240bhp) car. There are exceptions to every rule, but they are just that...exceptions.

Okay, let's stir the pot some more.

Here is a chart comparing my ubercharger to a friends FMII. I am making about 14 psi he is only around 10, but peak power levels are the same.
http://www.systemstrategies.com/miat...r_VS_Turbo.jpg

You have the better plot overall, and the better setup for SM2. Only drawback really is that you run 4 psi more to make that power.

you can comment on how easy it is to get 240RWH with a supercharger after you have done it. :) For every 240RWH sc you see on these forums, you will see 6 or more turbo cars (and usually they are significantly higher hp as well). This is a reflection of the difficulties you run into going for this power level with a sc. I am aware of someone who had a 150/62.5mm setup, well tuned runing 250+hp, who broke 2 sc's, (he did track his car) before moving on.

I went with a supercharger for several reasons. Most of my driving is in-town, from stoplight to stoplight, with very few freeway miles plus the main use of the car is for autocrossing. At the time it seemed both of these scenarios were better suited to a SC rather than a turbo. Having done a SC I do plan on going the turbo route next time just for the fun of it. Either are better than nothing.

truer words have never been spoken.

So, I read this thread and no one mentioned this guy: "FormerDatsun510Man". He is an m.net member. Here's a link to his setup: http://forum.miata.net/vb/showthread.php?t=265301

Hope it helps some of the SC guys.

When I was thinking of what sort of Forced Induction to get, my local Yoda came up with these words of wisdom...
No guesses which one I went for.....:)

Sorry, but 168bhp is not big power. Truth is if you want big power there are better ways to get it than a Miata. Most people running turbos are between 180 and 225 whp. There are exceptions sure. I agree that squeezing 250+ whp out of a supercharger is more challenging than a turbo, but most people aren't looking for that end. Sheesh this argument is like who gives better head a blonde or a redhead. Wait.. I already know the answer to that.

Now you got me curious! :giggle:

that being said, a good number of people on here do enjoy a challenge. that's why you see so many people piecing together home brew bits and running megasquirt rather than just bolting on a premade kit. yeah, money may be a factor there as well, but some people just HAVE to do it all themselves. and for that more power to them.

i do have to agree that i wouldn't be satisfied with a 170ish hp car. that would feel too slow too quickly.

and my money is on the redhead.

First of all, Redheads FTW.

Now, a couple years ago I found myself debating whether I should install a turbo or a supercharger system on my car. All of the anecdotal evidence I had suggested that superchargers offered much quicker response and better performance at lower RPMs, with turbos providing greater efficiency and top-end performance. The problem was that I had no actual hard data to back any of that up with, only a lot of rumor and speculation. "If only there were some dyno charts showing direct, back-to-back comparisons of turbo vs. a positive-displacement SC on the same car," I thought to myself... And then I realized that while said chart didn't exist per se, all of the raw data did, in FM's rather comprehensive dyno library.

As an thought-experiment, I decided to make a couple of composite dyno charts, in other words, overlaying data from one chart onto another, while maintaining scale. I chose to pull four charts for the '99, all taken on FM's old RotoTest dyno, and make two composites.

The first, below, is a U1 and a V1. Both were operating at the same maximum pressure, which I believe was ~6 PSI.

http://img29.picoodle.com/img/img29/...1m_13bd735.gif



And next, a U2 and an FMII, again both at the same pressure (I can't remember what it was now, but I made sure it was the same):
http://img32.picoodle.com/img/img32/...2m_6dbc698.gif



So, I was not at all surprised that the superchargers had a slight torque advantage at low RPM. What did surprise the hell out of me was how early in the RPM band this advantage ended and the turbo pulled into the lead. In both cases, the crossing point is in the 3,000 to 3,500 RPM range, and the difference to the right of that point (turbo over SC) is much more dramatic than the difference to the left (SC over turbo).

In other words, the turbos provided a much greater "area under the curve."

That said, I still believe that turbo vs. SC is principally a matter of preference. If you haven't driven both, there's no way to describe it other than that they just feel different. I just thought I'd share these charts, in the expectation that others may find them as informative as I did.

Your dilemma is kind of a win-win, so it's a good place to be. You don't hear too many people who go supercharger totally regretting it after words unless they're looking for ultimate power numbers. I'm running a DIY M62 at 8psi 167whp and I'm really happy with it. I have owned a turbo car in the past and I prefer the instant-on feel of the SC. To add a little to the discussion, I think the whine of a supercharger trumps the sounds of a turbo ;)

to anyone that has a s/c 'd miata...i'm absolutely in love with the sound of the supercharger that i hear on my brother's mustang, and i was just wondering if it sounded similar? he has a kenne bell 2200 supercharger on his GT. i was trying to find videos of a s/c'd miata, but i can't find many, and the ones i can find you can't hear the s/c. just wondering. if it sounds similar, i'll be going the s/c route for sure!
-Justin

I can here the S/C whine, over the 2 1/2" exhaust (JR stainless). Personally it's a little too loud...

Went to CMP in Kershaw, SC June 18-20.

Here's a pretty clean lap,

http://youtube.com/watch?v=KynpPfR23CU

My fastest lap for the weekend was a 1:52.035 by my Traqmate. Our AMB timing system had me at 1:52.039.

If the local dyno is open this weekend, I'll try to get a few pulls made.

KB

Dyno Disappointment
 

Went to the local dyno this weekend. I was disappointed with the results, which were 175 RWHP & 158 Ft-lb Torque. When had the car dyno'd last year, it made 200 RWHP. There were a lot of things different from last time, but I would have expected them to all be power adders.

Car Changes
Different Motor (105k salvage vs 113k salvage)
5th Injector w/Split Second Controller resulting in lower AFR (11 vs 12.5)
Coolant Reroute
Hondata Thermal Intake Gasket added
225/50/15 tires on car. 225/45/15 were previously mounted.
100mm crank pulley replaced with 110mm crank pulley (more boost @ 110/60))
EGR Delete
Idle Air Control System installed (may have been present at previous dyno - can't remember)


Dyno Changes
Different dyno locations(both were Dyno Jet - not Mustang)
Edited: Both pulls made in 4th gear.
200 ambient conditions: 75F, 100 Rel Hum; 175 ambient conditions: 88F, 60 Rel Hum

Could tires, ambient condition & Edited account for this much variance? I'll be doing compression and leak down tests later this week. I guess my first suspect should be the "new" junkyard motor.

On the upside, my quicker lap times aren't due to more HP! :)

KB

you did do the pulls in different gears.

Does anyone have the VF supercharger which is the centrifugal type? I have driven both types of SC and the centrifugal type was slow to spool compared to the other.

I went supercharger simply because I like the instant smooth power and its different than all the turbo miatas driving about. Built the car mostly for autocross and it works perfectly for that. I wanted big power with no lag so I put in a Ubercharger with a 15psi pully on a fully built engine and a link ecu and it flys. I assume its a bit cheaper to go turbo for big numbers and a lot more potential but im very happy with my setup and is way more fun in tight twistys.