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Kraftwerks supercharged K24 dyno results

85K views 70 replies 39 participants last post by  Magnus  
#1 ·
Hiddey ho, everybody. Finally completed the Kraftwerks K-race kit install on my EG tonight. Gotta say, the brackets that mount the Rotrex blower to the block are very impressive, fitting perfectly and being built to very tight tolerances. The install instructions are also impressive in their completeness. Installing the Rotrex and it's separate oiling system was a snap. Edit: I opted for the C38-61 Rotrex with a TSX crank pulley and 100mm s/c pulley, after consulting with Oscar Jr. and Tony at Kraftwerks. They predicted 400whp at 10-11psi with this setup and as you'll see below, they were bang on.

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Fabricating the front mount intercooler system and figuring out how to make a full width rad fit was a bit trickier, but thanks to Sasha at SG Motorsport all these challenges were sorted out. Once the FMIC system was completed Sasha retuned the KPro on U2Ndyno.com's Dynapack (which reads a bit lower than the local Dynojets). Vibrant Performance (thanks Donavan!) provided the intercooler and all the tubing and couplers required plus one of their velocity stacks for the intake.

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FYI, the K24A2 block is 100% stock (other than the baffled pan and modified oil pump), the head is stock other than Skunk2 Stage 3 cams and valvetrain, and I'm running a DC Sports K-swap header and 3'' Vibrant exhaust along with a RBC manifold and 65mm TB. Although I ran 94 octane pump gas on the all-motor setup, I decided to step up to 104 octane race gas for a little extra detonation protection.

Tuning didn't take long, since the all-motor mapping was actually very close to what the Rotrex needed. No power was found by adjusting cam timing or ignition timing in the upper rpm range, though Sasha did find a bit of midrange power by adjusting ignition timing in that area and a little fuel was added throughout, of course. Here's the last pull, after Sasha added a bit of extra fuel and pulled a bit of timing for safety:

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I'll post some more detailed pics of the install later, along with a video clip of it rippin' tec on the dyno. The plan is to track test it on Sunday. Can't wait!
 
#9 ·
To be honest I'm not sure if we would have lost any power with 94 octane. We really didn't tune the ignition maps any more aggressively than we had with the NA mapping that was tuned for 94. I really just added the 104 as a safety precaution. We probably could have made a fair bit more power had we tuned more aggressively for the race gas, but 400whp seems like plenty to me for a road race/time attack EG.

I'll have to look at the logs, but at 8 lbs we were probably making 350-360whp, but of course that was at lower engine speed. We were hitting 11 psi at 7600 rpm with the 152mm K24 pulley and a 100mm pulley on the charger.
 
#12 ·
Awesome progress on your EG, bro. Looking great so far. You should let us know what ya think after a few sessions at the track :)

The more and more I saw the Kraftwerks S/C kit and great success stories, the more I wanted one. I finally decided to put down my turbo pipe dreams (Hey....only to save them for a RWD build :D) and go with a KWSC kit for my K-REX in the making. The days are numbered on that kit not being in my hands. I am jealous, yet pleased you shared it with us.


Again, let us know what you think about it in detail!

Have fun with it!
 
#22 ·
Thanks guys!

Kraftwerks graphs always look like they want more RPM because boost obviously climbs with RPM (since the s/c is belt-driven). Loi's K24 EG revs to 9500 rpm and his graph looks the same...builds power right to the rev limiter. But in my case I cannot rev above 7850 RPM or I'd be over-revving the C38-61 Rotrex supercharger, plus I'm running a stock block so I don't want to rev too high.
 
#23 ·
Yar. Don't over-rev that thing, lol. That would suck seeing that thing go down the drain. Power curve? More like power mountain.

Not to get off-topic here, but what is Loi running to be able to spool to 9500 RPM? A C-30? And probably some different sized pulleys, I imagine. Any links to his build?

Keep up the good work MaxiMental :)
 
#24 ·
Yar! Shiver me timbers! Swab the poop deck! Hard to starboard! And long may your big jib draw! Yar! Man, I wish all our posts were in Pirate-speak! :silly:

Loi's actually running the same blower as me, C38-61, but he's running a different pulley combo so that he's making approximately the same boost at 9100 rpm (not 9500 rpm, my bad) as I'm making at 7500 rpm. He's running a fully built block, obviously. Here's a link to Loi's Kraftwerks install:

http://www.k20a.org/forum/showthread.php?t=60224&highlight=Sportcar+Motion+Kraftwerks
 
#25 ·
Dude, I celebrate "Talk like a Pirate Day" like some people do Halloween. I even fabbed up a trick peg leg, son. I gotta dig that thing out here in a week for my costume.....

Anyway.

Yea, I'm still getting my head wrapped around the KW S/C sizing and pulley sizes. C-38's seem to be popular, and I guess its working for what you and Loi wanted.

I gotta call up the boys at KraftWerks and have a chit-chat. I wanna crack the 500hp barrier with one of these bad boys. Hell, I was even entertaining the idea of twin rotrex's. We'll see what reason can come up with.

Thanks for the link :D
 
#26 ·
Not sure if breaking 500whp is possible with a single Rotrex. Perhaps with a C38-71 or -81 and the right pulley combo, a built engine and some aggressive tuning on race gas it's possible. I'm really not sure, but the guys at Kraftwerks are awesome so I'm sure if you give them a call they can help you finger it out. You might need dual Rotrexes like the Hondata landspeed car runs, which I think is making around 700whp if me ole Pirate memory serves. Yar!