Kawasaki Sportsbike Riders Club - Australia - Online Forum

Yep, it was already intercooled, but the turbo was running out of puff at high rpm, which would make the charge hot. I'm thinking of cryogen cooling (spelling??). that uses gas to keep the charge cool and comes in at a given boost. Might be a bit complex and costly, we'll see

frogzx12r wrote:..the naked 12 movement is growing, get in now and avoid the rush...

I'm very tempted. the 12's go real cheap at auction (smashed). What's the latest on your's. I saw your artist impression and i like it so far. You can buy so many custom parts for the 12 but where do you start. A "Big Wheel" streetfighter 12 would look nice. But wouldn't corner so well..
Post some pics as you go, i'd like to see the progress.

cryogen cooling? uhm, yeah i think it would be, given the volume of air that is being pumped through in even a normally aspirated 750cc bike at 9krpm at WOT its sucking in about 52-56litres of air a second. That's a lot of air to be pumping through.

The question ive got though is, whats the bike like now between being off boost and coming "on boost"? pretty tractable? or it just snaps on?

I guess oyu cant really run dual turbo's 'eh?

dual turbos would be a waste of space weight and time, unless he were aiming for a sequential setup

id like the idea of a bigger turbo but perhaps less boost? you can still be a little conservative on a 300hp bike


what sort of snail is it running at the mo?

a well matched GT series turbo should still spool up nicely... lotta technology in those turbos

The reason i was thinking about this is i was just thinking about the lag issue if you go up too much on the turbo size. I've heard of a few vehicles that had far too big a turbo and it took ages to spool up.
There was a jag in particular i think the xjr-15 they had on top gear ages ago, been hunting for the review, it had like a 10 second turbo lag when you put your foot to the floor, quite scary actually.

mike-s wrote:The reason i was thinking about this is i was just thinking about the lag issue if you go up too much on the turbo size. I've heard of a few vehicles that had far too big a turbo and it took ages to spool up.
There was a jag in particular i think the xjr-15 they had on top gear ages ago, been hunting for the review, it had like a 10 second turbo lag when you put your foot to the floor, quite scary actually.

wouldnt wanna do it on a race track...10sec is abt 1/10th the track..... ud be down the str8 into turn 1 when it kicked in...eeeek!!

The current Turbo is a high flowed hitachi ht-10. I was maxing that out in the higher rpm. I'm going to fit a Garrett GT-25. I'm planning a little less boost (10psi) but it should still give me an extra 50hp. The new turbo is a ball bearing type so it should spool up pretty well. It should be on boost by about 4-4.5k rpm. I aquired the replacment head and pistons today. the pistons are going off to have the crowns ceramic coated and skirts coated in a low friction stuff(kinda like teflon). hoping the motor will be back together in a month or so.

do you know what bits went into the HT-10? some high flows can make the numbers but with a pretty average delivery... the best part about the GT ball/roller bearing turbos isnt the bearings themselves, but the real lightweight turbine & compressor that still flow really well... thus great spool up

SocialSecurity wrote:do you know what bits went into the HT-10? some high flows can make the numbers but with a pretty average delivery... the best part about the GT ball/roller bearing turbos isnt the bearings themselves, but the real lightweight turbine & compressor that still flow really well... thus great spool up

Naah i don't know what went into the ht-10. That's interesting about the GT turbo. i know someone who's running one and it is so much better than what i had.

wat model ZXR is it? wat turbo have u got on it ???
sounds bloody insane!!

what sorta GT25 are you looking at?

off the top of my head the smallest one is a GT-25/10, which was fitted to S15 200SX's and would start to spool up around 2500rpm on a 2L motor and run out of puff around 6.5k... and good for upto around 200rwkw in such a car.... similar specs to a T28

lots of them on the 2nd hand market too

I' gonna get a brand new turbo. The bloke from GCG told me what it was. GT-254 (maybe) Good for about 280 hp. EXBEN has one on his zx9 turbo and it's real nice.

Saki wrote:wat model ZXR is it? wat turbo have u got on it ???
sounds bloody insane!!

It's a L model 94. there is pics up in here somewhere.