That would indicate that the other party doesnt know the janitor...

You being statistically minded and all.....how is one better than the other?



You mentioned a broken belt.

Has there been a documented case where the serpentine belt has broken?

I don't know you tell me :)


you mean in general, I mean in SCd cars? because last time I checked there were thousands of examples of snapping, braking, slipping of serpentine belts.. if you are referring to the JR or KW kits though, I see there are about 34 KW owners and about 17-18 JR kit owners maybe it's too early to tell but I know for sure there are some missing bolts :)..are we actually questioning the possibility of the things go bad when you track your cars and the importance of the safety net(s) when you need them?

you would be surprised the issues that I've dealt with my cars that saw track days .. for instance, at my last event I think I have cracked the OEM header ( not sure how I managed to do it) .. :)

How's your EGT? Do you have any data? I've seen headers (and cats) crack/fail from high EGTs with the FA20.

Are you really under the impression that the supercharger kit (rather than the HKS header) is responsible for that torque curve difference when both kits use the same compressor?

ive made up my mind.

im staying NA. thanks everyone

lol

I didn't datalog at this past event, I was only looking at the realtime data.. I am pretty sure my EGTs were high (also sure nowhere near close to any turbo setup but still) . Exhaust sound changed a bit, it's deeper and a bit louder with a small ticking noise.. I've removed the heatshield at the bottom of the OEM header and cannot see the crack visually but am planning to take it to a muffler shop so they can take another look.. I've also checked the connections to see if there's any sigh of smoke but connections look good..

that ticking (like rattling) noise makes me think it might be the cats, if that's the case I will most likely need to get an aftermarket header even though I don't prefer an aftermarket one because I really like the OEM piece with the proper heatshield and the fitment..

If these guys did a supercharger comparison using one example with a header, and the other without - then frankly, I dont even want to consider their test serious.

There is one for you: http://www.ft86club.com/forums/showthread.php?t=69999

The cats shouldn't be failing, even with track time. If you get the chance, keep an eye on EGT under load.

maybe there is a crack on the connectors that is not visible from the bottom, I will take the car to a muffler shop and ask them

Didn't bother to read the thread and just came to troll the hell out of the latest person to consider Kraftwerks instead of JR huh?

Yea

I have nothing better to do than to troll

KW will be happy to address your first three statement....but as for the last statement, I dont think JR would want you to go there as the internal documents would paint quite a different story from what you have either heard or are implying

I do find it interesting that KW business is up 800% and there are 3x more KW kits being developed since their departure 2 years ago.....Just sayin'

food for thought
 

just so KW owners, those genuinely seeking information, and lurkers don't get misled let us address some comments and issues in this thread:

Re: Cogged belt usage
here is a link to the rotrex technical manual:
http://rotrex.com/media/5fd67e23-1c1...20Handbook_pdf
- i cant seem to find any section discouraging the use of cogged belts. cogged belts are being used without reprimand for many years by TTS, Mountain Motorsports, and now KW. Which btw are all higher volume rotrex distributors/kit builders than JR. You would think that Rotrex would say something to these distributors if the ramifications for running a cogged belt were anywhere as serious as some naysayers are implying.
- KW would argue that cogged drive is better on the basis that you can run less belt tension thus increasing the life of the rotrex nose bearing, and you can also turn higher loads running less tension, less belt wrap, and narrower belts. Because the JR kit is running a 6-rib serpentine belt with less than 180 degree of belt wrap, it will more than likely slip with a smaller high-boost pulley (which have even less belt wrap) and it has no chance to turn the C38 blower which according to the rotrex data would require the use of atleast an 8-10rib belt
-in an earlier post someone said the following:
to which we respond that there is no issue with cogged belts off when you suddenly snap off the throttle. i am guessing that this statement implies that the belt should slip (because the main difference between the cogged belt and serpentine belt is that the cogged belt is positive drive that wont slip), but why would you want that? if it slipped under the load of sudden decelerations, it would also slip under the load of sudden acceleration. the supercharger has much less moment of inertia than the engine so it will always be able to match the accelerations and decelerations of the engine with no problem. if for whatever reason there was a condition where slip was necessary(i cant think of any), the rotrex can slip internally by design (ie smooth rollers + patented ramp effect) which woudnt be an issue (it's prolonged slipping and heating up of the traction oil that kills the supercharger).
as for the second statement, there are no vibration issues with the coggedbelt. the cogged belts and pulleys are design to maintain constant pressure along several teeth. furthermore by nature, a rubber belt dampens vibration. if there were vibration related slips issues you would see it in the boost curve; which we dont with a cogged belt.
also, we have no idea what 'outside of the cog is larger than the inside' means as there are no cogs on the inside...the rollers are smooth. finally, we do not know of people having issues in a road race situation.

Re: Oil Coolers
here are the KW/S2 adapters that you can use with various oil coolers:
http://store.skunk2.com/brz-frs-oil-...ooler-kit.html
and here are the complete oil cooler kits:
http://store.skunk2.com/engine-tunin...ooler-kit.html
** it should be noted that KW oil cooler has 3 more rows than JR for added cooling capacity

Re: Oil Thermostat
- we know many people are married to the idea of NEEDING an oil thermostat, but in reality you only need it for extreme sub-zero temperatures. i believe lab testing for oil is done down to continuous operating temperature of -40 ºF , so unless you are in a really really cold part of the world, you more than likely dont need one.
- the main benefit of an oil cooler would be that it will help the car warm up faster in extreme cold temps, and not let the oil to get too cold if your car is equipped with an air-to-oil cooler and you driving in extremely cold temps. If thats you, then separete oil thermostats are readily available through various outlets for less than $60. Heres a link for those that want to buy a good one at a great price:
http://www.summitracing.com/parts/prm-1070/overview/
-for those in warmer climates, you dont need one and you are arguably better off without one. recently we were doing tests on fuel rails and logging temps...we were quite surprised by how much heat was generated by disrupting internal flow of fluids through the fuel rail and line, but thats another story.

Re: Summary of Differences between KW and JR kit
- KW kit is upgradable to running a high boost pulley or big C38 blower, this is possible because of the KW independent drive layout. JR kit cannot be upgraded without a significant redesign. The current design has insufficient belt wrap to to turn a smaller pulley, and even if they find a way to get more belt wrap, they still would not be able to turn the C38 blower with a 6-rib belt and not have slip. Recently it appears that JR decreased the size of their tubing going into the throttle body, we are guessing they need more clearance because they are looking into trying to reposition the charger for more belt wrap; we are just guessing.
- KW has bigger tubing. 2.5" tubing on the compressor outlet, and 3" tubing into the throttle body. This is made possible because of the KW independent drive layout offsets the supercharger and also the fact that the KW kit comes with a custom washer bottle that allow us to run the larger hot pipe.
- the KW kit has a larger intercooler.
- the KW kit draws cold intake air from inside the bumper cover; which runs 10-20 degrees cooler than in the engine bay.
- if you ever have a belt issue for whatever reason, the indpendent drive of the KW kit insures that you can drive home just fine. That is not the case with any of the other SC kits. We are not saying their layouts are designed to fail, just saying that if anything happens to no fault of their own (ie a 3rd party supplied idler fails) you will need a tow truck or install another belt roadside.
- we think the quality of the KW kit is better and can be seen in our billet CNC pocketed 3/4" mounting plate, mounting/reinforcement brackets, and billet machined idler pulleys. It think JR uses 1/4" or 3/16" mounting plates and off the shelf store bought plastic idlers.
- JR did beat KW to the punch in terms of CARB approval, but the KW kit should be CARB approved soon (car is in the lab already, then its just waiting for carb to issue the EO number) and we will be seeking approval for the C30 and the C38 blowers.

Re: Ridiculousness
-I find it ridiculous that JR pundits feel compelled to come into this thread and try to get people to focus on non-issues and avoid discussing the elephant in the room which is the non-upgradeability of the JR kit. Why the need to focus on broscience threads discussing missing bolts or less than perfect instructions? Or getting up on a psuedo high horse and spew rhetoric like they only support high quality products made by established and experienced companies. Well here is some news for those who dont know, Group-A (KWs parent company) has been in business 20 years and have extensive development infrastructure in house. We have a full staff of R&D, customer service, operation personnel. KW is committed to great customer as many of our customers will attest to, and customers have only complimented us on the quality and build of the kit and its components. People can say what they want, but the fact is that a company in the the ultra competitive dog-eat-dog performance aftermarket doesn't get to where we are at by making bad parts or not caring about our customers. As for JR, yes without a doubt they have a legacy name, but they still have a lot to prove in todays marketplace its not the same as the 80's or late 90's. The fact of the matter is at this time around they are just 3-4 people working out of a small business park unit and a far cry from their former glory. No dedicated CAD designers or fabrication specialists, and not even an inhouse dyno...you get the picture. So to all the JR fanboys...instead of picking at KW nits, go back to the JR mothership and ask them when and if JR customers can expect power upgrade options. Then you can start a separate thread reporting your findings or their official excuses. I apologize if my comments seem angry at times, but i'm Just sayin.