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Hi guys Kaspa here from down under in sunny Queensland Australia, i have a little Lotus 23 race car i built with a K24 Z3 turbo in the rear, fun little jigger, it only weighs 540kg and has a modest 295 RWHP and 450ft lbs of torque on just 10lbs of boost at 7000rpm, Being very new to the Honda engine as ive never worked on one before, so if i ask the occasional dumb question go easy on me.
 

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Arouse the DAMPFHAMMER!
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Hi guys Kaspa here from down under in sunny Queensland Australia, i have a little Lotus 23 race car i built with a K24 Z3 turbo in the rear, fun little jigger, it only weighs 540kg and has a modest 295 RWHP and 450ft lbs of torque on just 10lbs of boost at 7000rpm, Being very new to the Honda engine as ive never worked on one before, so if i ask the occasional dumb question go easy on me.
Welcome Kaspa, this is a very nice and rare Lotus K-swap. I know just another one here in Europe eith an K20 NA. Would be glad to see a thread of it.
 

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hi mate yeah i have a mate Frances in Austria that also has a k20 in his but he has mounted his east west with the orig trans, where as mine is north south coupled to a Subaru 5 speed trans axle.
i built it originally with a K20 type R engine but the timing chain let go and stuffed it after 2 meetings, so i purchased the 24 and decided to fit the turbo as i had it sitting on the shelf and my work of art headers i built for the 20 wouldn't fit as the exhaust manifold is part of the head on the Z3 so i just made an adapter plate and fitted it up and it all just squeezed in under the rear deck, the engine is other wise dead stock apart being dry sumped, an 80mm manual throttle body onto a Skunk inlet manifold, and i run it on E85.
https://flic.kr/p/2hvKb89 on the graph the red line is the K24 the blue line is the K20, just a small improvement.lol.
https://flic.kr/p/2hDuK9g this is a pic of the K20 set up with the trans in place
https://flic.kr/p/255TnEB any questions fire away.
cheers Kaspa
 

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Arouse the DAMPFHAMMER!
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hi mate yeah i have a mate Frances in Austria that also has a k20 in his but he has mounted his east west with the orig trans, where as mine is north south coupled to a Subaru 5 speed trans axle.
i built it originally with a K20 type R engine but the timing chain let go and stuffed it after 2 meetings, so i purchased the 24 and decided to fit the turbo as i had it sitting on the shelf and my work of art headers i built for the 20 wouldn't fit as the exhaust manifold is part of the head on the Z3 so i just made an adapter plate and fitted it up and it all just squeezed in under the rear deck, the engine is other wise dead stock apart being dry sumped, an 80mm manual throttle body onto a Skunk inlet manifold, and i run it on E85.
on the graph the red line is the K24 the blue line is the K20, just a small improvement.lol.
this is a pic of the K20 set up with the trans in place

any questions fire away.
cheers Kaspa
Hi Kaspa, yes I know Franz from Austria. We spoke about his ITB system of the Lotus 23. You've met him already?

This is a very huge torque for that tiny lightweight chassis. What will be the application for it? I am curious why you use a 80 TB on a 540 kg chassis with that much torque. Racing it on circuits will get challenging because of the power gradient over butterfly angle...30° will be almost 75 % of WOT torque in stationary conditions. This maybe makes the car very sensitive to your right feed action.

Nice headers you are building. We thought about it for the DAMPFHAMMER engine, but the clearance demand in rectengular direction to the crank axis is to big for the S2 chassis.

I wonder what makes the torque curve of the K24 that calming in the beginning, seems like boost setup is not flat, more a linear curve. Seems like something is holding it back from working. Did you tune it? I am curious about the log and calibration, if you don't mind to share.
 

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Hi mate, yes ive known Fran from very early in his build as he joined my face book group. "the scratch built workshop"
the car is actually very easy to drive believe it or not. and i am going to make it even easier by changing the diff from the 4.4 thats in it now to a 3.9 to use the torque.
Its a bit tricky to get off the line from a standing start but ive now configured the launch control so that should make it a bit easier.
I originally got the 80mm throttle body for the Type R K20 engine, but it seems to be ok on the 24, admittedly you must be gentle on the throttle to control wheel spin, but its not to bad, the fact i run F3 super soft slicks certainly helps in that regard, as yes it is a straight race car not a road car at all.
now the tune, the secret to the torque curve is in the variable cam timing, my tuner played with the cam timing to achieve such a curve, I do have a boost controller fitted which is also ECU controled that helps a well. the ECU is a Haltech Elite 1500, and i run a wide band o2 sensor, a Flex fuel sensor and the boost control solenoid.
The only other thing i can add, when i went up to pick the car up from the dyno he had over 370hp at the wheels but i said that was way to much so he de tuned it back to its present 300 for now, if we need more at least we know its there for the taking, but somehow i dont think we will.
i will try to get a screen shot of the fuel and ign tables for you to look at,.
here is a video of one run up a damp hill climb where we won first in class on its debut run.
https://flic.kr/p/2gv4Y2X thanks for your interest in my little rocket.
cheers Kaspa
 
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