Kraftwerks Rotrex Supercharger Discussion

[gmsii]

Originally Posted by Calum

I'm really surprised to see you've just tacked another pulley onto the stock pulley. You could achieve much better quality control over the axial position avoid possible angular misalignment issues by replacing the stock pulley with one that incorporates both rings. Also weight gains could be kept low with proper design and material choices.

the hub adapter is machined with the same precision that would be required of making a completely new pulley. it is located and datum'd off of precision machined faces so alignment is not an issue. its a simple and cost effective solution with no real penalties.

also, we are not advocates of replacing the factory damped crank pulley with with non-dampened aluminum replacements that do a poor job of neutralizing harmonics in the crankshaft.

[gmsii]

Originally Posted by OICU812

Question.. If the drive pulley for sc belt is coming off crank pulley what if the customer has a aftermarket one such as a Raceseng, kart boy, Perrin? Some of these such as raceseng like I have are faced very different then stock one.

because the crank pulley adapter is toothed, there is no belt alignment issues (as there would be with a serpentine belt) as long as the adapter sits within +/- 5mm of its position using the stock crank pulley.

[gmsii]

Originally Posted by CSG Mike

Why is the output so rough over 6k RPM? I noticed the smoothing was maxed on the dynojet run(s). Will this be smoothed out as you guys continue to develop the tune further?

How much boost is this at, and what RPM does the supercharger see? Is there overhead for more power? Is the increased redline safe?

The powerband is really meaty from 5500-redline... This should be fun at the track and canyons.

generally the high rpm choppiness is from the spark plug...these were stock plugs, we will try a step colder...should smooth it out

the blower is set up to hit 10.2psi with a max engine RPM of 7800.
we have a smaller pulley set-up where the engine redline is set for 7300rpm engine that makes about 13psi boost and about 15whp more in the midrange and 30whp more peak

[Calum]

Originally Posted by gmsii

the hub adapter is machined with the same precision that would be required of making a completely new pulley. it is located and datum'd off of precision machined faces so alignment is not an issue. its a simple and cost effective solution with no real penalties.

also, we are not advocates of replacing the factory damped crank pulley with with non-dampened aluminum replacements that do a poor job of neutralizing harmonics in the crankshaft.

Could you post a pic of the hub adapter to help clarify? I was thinking the new pulley was somehow bolted to the OEM pulley. My worry about misalignment issues was that the OEM pulley wouldn't be perfectly machined as it looks like they are hard against each other in the pic.

[Calum]

Originally Posted by gmsii

generally the high rpm choppiness is from the spark plug...these were stock plugs, we will try a step colder...should smooth it out

the blower is set up to hit 10.2psi with a max engine RPM of 7800.
we have a smaller pulley set-up where the engine redline is set for 7300rpm engine that makes about 13psi boost and about 15whp more in the midrange and 30whp more peak

Do you expect the smaller pulley to play well with 91 Octane? Would it possible to run a restrictor to help limit top end boost if it wont work well with 91?

[CSG Mike]

Originally Posted by gmsii

generally the high rpm choppiness is from the spark plug...these were stock plugs, we will try a step colder...should smooth it out

the blower is set up to hit 10.2psi with a max engine RPM of 7800.
we have a smaller pulley set-up where the engine redline is set for 7300rpm engine that makes about 13psi boost and about 15whp more in the midrange and 30whp more peak

Would a smaller gap work with the stock plugs, or would a different plug be absolutely necessary for a smoother powerband?

Thank you for the info!

[F1point4]

Originally Posted by gmsii

the hub adapter is machined with the same precision that would be required of making a completely new pulley. it is located and datum'd off of precision machined faces so alignment is not an issue. its a simple and cost effective solution with no real penalties.

also, we are not advocates of replacing the factory damped crank pulley with with non-dampened aluminum replacements that do a poor job of neutralizing harmonics in the crankshaft.

Are you planning to test/certify the kit with the use of the ATI Super Dampers???

[gmsii]

Originally Posted by F1point4

Are you planning to test/certify the kit with the use of the ATI Super Dampers???

we havent had a chance to look at this....we have designed it for use with the stock damper....i'm sure other dampers can be used, but at this point we will have to defer to enthusiast base to determine all the nuances of what parts can be used instead

[djdnz]

@gmsii

Can you comment on replacing the serpentine belt? I'm guessing the whole supercharger has to come off, how time consuming is that process?

Secondly, how do you get at the air filter if you want to clean or replace, is there any way of avoiding removing the bumper or is that the only way?

Also, how accessible is the oil filter? I already have trouble with my, albeit somewhat antiquated, oil filter wrench with the stock setup - this looks quite a bit more cramped.

[gmsii]

Originally Posted by djdnz

@gmsii

Can you comment on replacing the serpentine belt? I'm guessing the whole supercharger has to come off, how time consuming is that process?

Secondly, how do you get at the air filter if you want to clean or replace, is there any way of avoiding removing the bumper or is that the only way?

Also, how accessible is the oil filter? I already have trouble with my, albeit somewhat antiquated, oil filter wrench with the stock setup - this looks quite a bit more cramped.

to replace the cogged belt you basically have to remove the mounting bolts and the silicone intake coupler....so 4 bolts and hose clamp...tensioning is easily done because we use a manual tensioner

regarding the air cleaner...we decided to place it in the cold air area of the bumper for performance and space reasons....removing the bumper is not very hard and filter only needs to be cleaning every 30,000-50,000 miles

as for oil filter access....its not a problem...dont know about using a p-clamp style filter wrench, but definitely not a issue with a socket style oil filter wrench or even just using your hand with a piece of sand paper

[Robftss]

Originally Posted by gmsii

Below is comparison of stock vs KW kit with stock header and exhaust


Below is boost graph...peak boost is 10.23psi @ 7750rpm


From the data below, you can see that air temp increase over ambient air temp is only about 10*c (18*F)

Very detailed info. Nice results. Thanks!

So starting from a bone stock FA20 these are the results for your reg. $5095.00 full tune kit?

Using the ~ 4.5hr install time ~ $400-$500 for a shop to integrate.

The gearbelt looks great, what will that retail for ? Just as a precaution.

[gmsii]

Originally Posted by Robftss

Very detailed info. Nice results. Thanks!

So starting from a bone stock FA20 these are the results for your reg. $5095.00 full tune kit?

Using the ~ 4.5hr install time ~ $400-$500 for a shop to integrate.

The gearbelt looks great, what will that retail for ? Just as a precaution.

yes...the dyno graphs are for the base kit...on the dynojet dyno the numbers were 272whp. on the current special, this same kit is going for $4495....thats really hard to beat

the double sided cogged belt will be available for about $80

[grostoine]

SO, SEMA's over. I want updates.

When are we doing finale paiment? When the kit are supposed to be mail?

Just to make sure, the msrp price is 4495 msrp for a tuned kit. For the first thirty it's still 3695 minus the 319$ deposit for a tuned kit?

Is there a choice of color for the piping? What are the upgrade that can be made execpt puting a C38 to upgrade power?

[gmsii]

Originally Posted by grostoine

SO, SEMA's over. I want updates.

When are we doing finale paiment? When the kit are supposed to be mail?

Just to make sure, the msrp price is 4495 msrp for a tuned kit. For the first thirty it's still 3695 minus the 319$ deposit for a tuned kit?

Is there a choice of color for the piping? What are the upgrade that can be made execpt puting a C38 to upgrade power?

$3695+ shipping and tax (if applicable) is for the base 'you tune kit'
$3895+ shipping and tax (if applicable) is for the base kit w/ ecutek map
$4495+ shipping and tax (if applicable) is for tuned base kit w/ecutek hardware and mapping

the piping comes in gunmetal metallic silver...its easy enough to spray paint or powder coat

easiest upgrade will be changing to a smaller pulley...this brings the boost up from 10.2psi to 13psi....but requires the rev limiter to be lowered to 7300rpm....this upgrade nets between 15-30whp

ship date is the last week of this month...we are waiting for some final parts to come that arent expected to be received until Nov 21

a customer service rep will call or email every single customer to let them know what all the options and add-ons are available at that point