Sam's build thread

[sambb]

600hp (300hp per litre) 2.0L 3 cyl, freevalve, twin turbo...….. nuts!!

https://www.roadandtrack.com/new-cars/car-technology/a31451281/koenigsegg-gemera-engine-specs-analysis/

hopefully freevalve will save the IC engine

[sambb]

I was talking with a friend the other night who is building a 3.4L 2JZ Lexus 1s300. The Borg Warner EFR turbo hes using isn't the full motorsporty one, its a rung down from that, but I was surprised when he said that it still ran an internal diverter valve arrangement. Is the idea behind that that the internal DV will be whats used in day to day throttle shut moments but it assumes that you'll still run a BOV ie the BOV be sprung so that it will remain shut for 90% of daily driving but will come into play for harder driving?

[Sydneykid]

I was talking with a friend the other night who is building a 3.4L 2JZ Lexus 1s300. The Borg Warner EFR turbo hes using isn't the full motorsporty one, its a rung down from that, but I was surprised when he said that it still ran an internal diverter valve arrangement. Is the idea behind that that the internal DV will be whats used in day to day throttle shut moments but it assumes that you'll still run a BOV ie the BOV be sprung so that it will remain shut for 90% of daily driving but will come into play for harder driving?

My guess is it has got a DV (in Borg Warner speak a CRV -compressor recirculation valve) so he is using it. DV's are also good for engines with MAF's as the air "stays in the system" so you don't get an excess of fuel when the BOV opens and lets out some air. There is also a claim to less lag with a DV but I can't say as I have experienced it. BW do sell a DV blank off so they recognise that not everyone wants one. My guess, for the "race" turbo it's just a box ticker (yes, tick, it has a DV).

Worth a read http://www.turbos.borgwarner.com/fil...ical_brief.pdf


Cheers
Gary

[pogopins]

Where I'm scratching my head though is how the hell a 7AGE can be in a Barina?!!

IIRC the IPRA engine rules are (a) same number of cylinders and (b) same marque

Holden sold badge-engineered Corollas (Nova) that had A-family engines, and badge-engineered Camrys (Apollo) that had S-family engines

I don't know if any Novas had the wide (G) cylinder heads though! Not sure how naughty that is? And I bet Toyota didn't bother making 4A/7A blocks with the Holden logo stamped in them...

[sambb]

Ah the Nova. That's right. A piece of crap that I'd blocked out of my memory. What a little weapon that car in the vid is.

[Sydneykid]

IIRC the IPRA engine rules are (a) same number of cylinders and (b) same marque

Holden sold badge-engineered Corollas (Nova) that had A-family engines, and badge-engineered Camrys (Apollo) that had S-family engines

I don't know if any Novas had the wide (G) cylinder heads though! Not sure how naughty that is? And I bet Toyota didn't bother making 4A/7A blocks with the Holden logo stamped in them...

Cylinder heads are free in Improved Production.

Cheers
Gary

[sambb]

Gary would something like this be legal under IPRA rules then? Mk1 Golf at Bergen hillclimb. 1400cc VW block with hayabusa head.
https://youtu.be/mSQRoGxRTCk?t=2643

Or this. Same Mk1 or 2 (not sure) VW 9A or KR block destroked to 1170cc and then turbo'd to have equiv capacity under 2L - oh and with a busa head too? Or is changing the induction method to forced from NA disallowed?
http://www.werace.tv/hillclimb-monsters/400hp-vw-golf-mk2-1-2l-turbo-11-000rpm-hayabusa-engine-head-swap

[pogopins]

wow that thing is fast! love the angry noises too

[Sydneykid]

Gary would something like this be legal under IPRA rules then? Mk1 Golf at Bergen hillclimb. 1400cc VW block with hayabusa head.
https://youtu.be/mSQRoGxRTCk?t=2643

Or this. Same Mk1 or 2 (not sure) VW 9A or KR block destroked to 1170cc and then turbo'd to have equiv capacity under 2L - oh and with a busa head too? Or is changing the induction method to forced from NA disallowed?

MK1 is prior to 1/1/1986 so OK to turbo. Post 1/1/1986 has to be turbo originally.
Cylinder heads are free, so no issue with using a hayabusa head.
A 36 mm restrictor is mandatory for the MK1 weight, which will limit it to around 400 bhp. With the right spec turbo and ~10,000 rpm it should be capable of that easily.
FWIW, the capacity limits in IP are +2%, so 2040 cc's is OK, / 1.7 = 1200 cc's.

Cheers
Gary

[sambb]

Ok. Has anyone ever gone to that extreme in IPRA or aside from budget constraints is it more a case of not wanting to be that guy that's so far outside of the spirit of the rules?