Great example.

With a pulley driven centrifugal S/C if you are cruising along at 2-3k rpm and come to an incline, even on the smaller 10psi pulley, you would be lucky to build 2-3psi. Even then you would be putting quite a load on the motor with the throttle mostly or all the way open and you would be exposing it to this condition for a long period of time.

Especially compared to a comparable size turbo which would probably hit as much as 15psi @ only 3k rpm if you desired, and in the period of time it would take to spool the engine speed would've increased and stress would be lower.

Trust me, go turbo on a motor like this, it's cheaper, basically just as easy and more efficient. And you won't be robbing power right off the crank.

How much torque you get out of either depends on the tune.. boost, IAT, lambda, and spark angle.

Don't worry about the AT being able to handle it, it can. Just get a bigger cooler with a switched fan if you are concerned and make sure the fluid is in good shape.

The L-series motor and trans (AT or MT) are far more stout than anybody seems to give them credit for, even now that the GD has been out and about for a decade.

 

Until you are familiar with how the constant velocity traction drive planetary transmission works on the Rotrex superchargers or have been behind the wheel of a car that is equipped with one, you are speculating as to how you think they perform and when the torque is coming on.... I finally got a set of tires that hook up before 45 MPH in 2nd gear...

 

They are a great design, and certainly the best iteration of the Centrifugal S/C that I know of, including the ProChargers.

It's a clever bit o kit thats for sure:


I am not saying it wouldn't create noticeably more torque Tex, but having driven and tuned both a Rotrex S/C'd Miata and a Prelude (Both Jackson Racing kits) I have to say the delivery is much different. I'm thinking mid-range grunt.

They scream up top, no doubt. I am not knocking them, it just comes down to $/hp and efficiency for me, as well as power under the curve.

This is how the boost builds on them:


It's just how I am looking at the situation.. lets say both compressors are set to make 10psi for instance.

A GT25R can make that 10psi on an L15 @ 3k or so and hold it to redline.


The Rotrex S/C is pulley'd to make that 10psi just before redline.


The dive in the turbo graph is due to the tune. That was on an otherwise stock engine as well and apparently they didn't want to push their look back when the test was done.

I would go so far as to say the Kraftwerks kit comes with a much better tune though. An FIC would allow you to tweak it yourself, though this applies to either S/C or T/C as it is a piggy back system.

 

I have been keeping up with the CVT bike traction drive hubs for years... I can't believe that Rotrex wouldn't allow it to actually operate as a CVT unless it ha something to do with the traction oil and what it is capable of doing It seems to me that from just under 4000RPM until the rev limit, at about 78 going down hill and 75 on flat land, the thing is pulling hard..The rotor is turning at the same rpm at low crank rpm and gears down to not rev too high as it is near redline. which is why they can use smaller injectors than if it spun on like a turbo... I'm too damned old to be dicking around and blowing things up so unless there are really miracles I have to stay with what I've got but maybe with a smaller pulley..... I need to stay away from facebook too..... Suddenly I'm everybody's grandpa.....

 

It is making about double the WTQ it would stock (100-120) on the high boost kit @ 4k rpm. So I bet it moves!

If you could find a smaller pulley and the tensioner could take up the slack, all you would have to do is add a bypass-valve to control the excess.

Grandpa eh? Easily one of the more bad ass m*****f***** grandpas anyone could ask for.

No wonder you're in high demand

 

I was thinking about adding the secong radiator fan that is missing on my car (I don't have A\C!) and maybe activating it via the switched 12v function of my FIC or i could just put a pressure switch on my future FMIC piping and making it switch on when boost get to something like 3 or 4PSI just to make sure...

As for my ATX tranny oil, i change my fluid every 30 - 40k km with stuff from Red Line! To date, it seems to like it way better then the Honda Z1 or DW1 fluids... Shifts are crisper and fluid is more resistant , or so i think, as it won't get black in no time like the honda stuffs.

MARKO!

 

I meant more along the lines of getting a larger oil cooler for the AT its self and then putting a switched 5-7" slimfan on that cooler.

A hobbs-type pressure switch would work or you could do it based off temperature using a thermistor.

 

-First: Your saying your motor is about to go? How is that? Do you have a crazy amount of miles on it? Or maybe likely driving it on a bad tune on that FIC? Or starved the pickup? I just don't see how your engine is going so soon being N/A. There's quite a few GD3's out there turbo or super charged running around 10psi trouble free on 100% stock motors.
For less than the price of just the (aftermarket) con rods alone you could find another complete L15 and just pick up the Kraftwerks kit and bolt it on and be done with it.

-Second: From your first post I (and probably everyone) assumed you were after 200 or more horsepower at the wheels, what with a full build on the motor. In your quote it looks like all your after is a strong enough power level to never have to downshift on hills? Well save your money on that motor build and just go with the kit plus a pulled replacement motor. You will be more than happy with it. I hear it's hard to get a hold of Kraftwerks lately so you might want to get that figured out before you go any further. Also since your auto (I'm sure you know this already) you'll need to see if they can supply you with the bigger supercharger from the MT kit.

 

The FIC was installed to ensure that my AFR won't bee too lean as my bolt-ons were allready making it runningt Über lean (13.5 - 13.8:1 AFR depending on weather) in the upper revs. Not the best piggyback for ''All-Motor'' performance but i planned on supercharging the car last summer. All maintenance was done with AMSoil or Red Line oils and it never ran out of oil... A tech at my job said it sounds a lot like a piston pin related knock and\or severe piston slap and asked if i ever abused the engine with heavy dozes of nitrous or whatever. Maybe i'm one of the first to have a bad motor.... And i don't want to put another stock engine in it as i prefer to upgrade the car instead of putting back stock components in it. And, as i'm planning on boosting the engine, i want a much more solid foundation to start working with!

As for the S\C, i know leonine have the bigger S\C installed on his A\T Car, but i went on Rotrex's web site and i saw some tuners that put a C30-74 S\C unit on a Ford Fiesta. Much bigger then the MT Fit 's C15-60... I was wondering if someone know if it would be easy (possible!) to install a C30-64 S\C on the fit and probably have more low end grunt as well as more power potential later!? That would probably make the car torquier enough to help prevent much of the downshifting i experience now.. Just like i said, having the car spin past 5k RPM at minus whatever degrees with the engine cold is something that get's me worried as i have no choice but to pass there twice everyday... Right now i, at least, give the car a 5 min warmup and i roam in the streets a little bit before going home to give the poor little L15A1 a chance to get at operating temps but it's beginning to piss me off at something like 5$ a gallon...

Marko!

P.S. I don't have a target WHP fixed! Just something that's gonna give me more torque so the car could be more streetable for now... After all, it's not like i planned on banging on my friend's 60Trim SRT's and Stage 1 SS TC Cobalts!!

 

Rotrex A/S

Marko!

 

Just a theory question here, but I'm pretty sure the computer compensates for a lean or rich condition up to 20%, after which its turns on the check engine light? Even with bolt-ons, the computer should see a lean conditon and richen the mixture. Thats what the Short Term and Long Term fuel trims (if reading on a scan tool) do, right? Just curious. I wonder what the AFR is on a bone stock Fit at higher rpm? Lean makes power, so maybe the stock tune leans it out at higher RPM to make the little hamster go?

 

It can go quite rich if you are using only 87oct. As rich as .78 Lambda. Especially around peak VE.

But under ideal conditions (IATs <50F + couple gallons of C16 mized with 93 E0) I have seen .89 Lambda. There's really no benefit to going leaner than that, especially since Max Rich Torque is generally around .85 on pump gas.

There is an extent to which lean is making power vs. raising in-cylinder temps. That is typically .85 Lambda. DOHCtor's .92-.94 is just asking for trouble, even on an NA motor. But we are relatively high comp so there is that to contend with as well.

The Fit ECU is quite finnicky, especially the GE8s. It is all about saving its self and limiting the torque output. If he was indeed seeing O2 readings that lean, he has drastically changed his VE.

 

The Fit ECU will target an AFR of 14.7:1 in part throttle condition and will ignore O² Sensor at WOT! I would'nt have installed a FIC if it would have been wise enough (Programmed...) to maintain an AFR near 12.5 - 13:1 at WOT! At WOT, it think's the motor is still stock and as it's ignoring the O² sensor, it injects the same quantity of fuel that it think would be optimal for a stock motor...

When i changed my intake and spark plugs for the Fujita SRI and IK22, it was probably running a more optimal AFR ''Power Wise'' as the gains were quite noticeable in day to day driving. After i putted a DC Header and A-Spec Axleback, it felt like a gained only a little power, if any at all... The Weapon-R Intake Manifold then destroyed any notion of torque the engine didn't have in the first place as the runners are way too large for the size of the ports!! I will more then probably reinstall the stock manifold for that reason... The Weapon-R just sucks at producing power... i've lost a full second in the quarter mile with it! Fortunately, i've been able to gain some power back with the FIC but the Intake manifold will have to go!

Marko!!

 

Interesting and surprising. I wouldn't think the stock ECU would be dumb enough to let the AFR go lean under any condition, expecially at WOT. Is this a GE thing, or is the GD just as silly? Lean makes power, but also melts things if taken too far. I would think if it can't compnesate for the bolt ons it would throw a MIL. Food for thought. I'm picking up my '08 Fit tomorrow (YEAH! ), and would like to put the SC kit on next summer. I planned on doing the header/exhaust before putting the kit on, but not if the thing is going to run lean at high RPM's, I'm guessing with 90 HP I'm going to be winding the thing up quite a bit to keep it moving, lol.

 

Well, that's what my AEM AFR gauge was telling me! Maybe you could be ok with a Short Ram or CAI, Denso IK20 or IK22 Spark plugs and a DC Header, but beyond those mods mine was beginning to be too lean!

Marko!

 

I'm not arguing that you saw lean AFR's. I'm just surprised at Honda for tuning the thing that way. I wasn't planning on doing an intake, since the the SC comes with its own intake/filter set up. I figured on doing the header/exhuast so its paid for and on the car before I get the SC. I'll have to drive mine around with my scan tool from work and watch what the front O2 is reading stock, just for a baseline before I do anything to it.

 

It's called open loop operation and its not just something that Fits or even Hondas in general are pre-disposed to. They run off the factory maps beyond a certain load, rpm and tps.

If you have changed the VE, you will have FUBAR'd the tune.

The reflash that comes with the KWSC kit, with the appropriate injectors, can keep things nice and rich to stave off detonation. Beyond that, thats what we have knock sensors for.

 

Gotcha, thanks. I wasn't aware that cars went into open loop at WOT/high RPM's.

 

The new Weapon R intake manifold's runners must be larger than the older ones like I bought from kylerwho... I checked the openings on it against a phenolic gasket for a Fit manifold and the Weapon R is the same size as the gasket... Does anyone know if I should use any kind of sealer or just install the gasket dry. It is pretty hard material so I was thinking something like Gasgacinch would be the best stuff to use, but I'll have to order it online... That stuff was only available at VW dealer's parts departments back when I used it last... That was before most Fit Freaks were born.

 

I installed mine dry on! No leaks! Just be careful not to strip the threads on the head as the stock bolts wont go as far in the head with that thicker gasket!

Marko!!