if they're not clutchdumping or transbraking at 6000rpm then dowelling is fine - like i said it's only under big load (like hard launches) that makes the rear rotor housing walk.

but we're WAY off topic so i'll leave it there.

Hmm, thats interesting about the dowelling. I ran a dowelled 13B for a couple of years as a daily driver with no problems at all, running around 350 rwhp with a bit more when I raced it. Same with a mate, who got it done around the same time. In fact I think his engine is still getting around somewhere and this is like 4-5 years later.
And my bro's currently running one thats around 430 rwhp, but it hasn't done many kays yet. I hope it doesn't run into any cracking problems.

to fit the renesis rotors you need to change the apex seals to the oldskool type with corner seals. just a bit of machining there.

dowelling is actually detrimental to a boosted rotor. there was a massive comparison on Ausrotary a few years ago and evryone who has had it done swears they will never do it again - a few people had them crack in exactly the same spot they did BEFORE they dowelled them.

it removes the original cast metal and basically you are "building in" a crack by sleeving it. poor engineering practise - like welding thick plate and not tapering the flange to be welded. you are "building in" a crack in between the two welds. same principle.

you should use the thick sump gasket for any performing motor that undergoes hard launches - boosted or not. load is load and a walking rear rotor housing = death regardless of whether there is a turbo off the side or not.

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Renesis rotors!! What needs to be done to fit these in a 13B?
Hmmm....a single rotor 13B PP with renesis rotors in my 1000 ute. It's sounding very tempting!
And by the way, I bought second-hand S5 rotors for about 400 bucks so that would make the renesis ones free??

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I've always seen dowelling as way of keeping the engine together under high boost, so I wouldn't use it in a PP anyway. The big sump gasket "brace" seems like a good idea though.

i haven't come across any 5spds at all - genuine anyways. your mate must be one lucky SOB pity he busted it!

EFI PPs - they're A LOT more tractable at lower RPM and less prone (but still very prone) to popping flames on deceleration. they still buck like a kangaroo at sub 3000rpm a mild load (cruising) but like i said, knock it back a gear and it all smooths out and your fuel efficiency goes up!

use carbon kevlar apex seals - you can get them from racing beat - they're a lot nicer on the engine than steel or ceramic seals, last longer than straight carbons and a lot less prone to breaking at high rpm. a fair amount of $$$ but worth it IMO.

i will be building one at a much later date - i have ex-mazda factory PP housings in my old man's shed just waiting for renesis rotors (a new pair from mazda and modded to suit an older 13B is about $400 cheaper than S5 rotors alone!) and a 55IDA TB.

if you want even more reliability at higher RPMs you can build a thin bridge over the inlet and exhaust ports to stop the apex seals banana-ing out at high rpm when they move across the port which causes breakages.

and skip dowelling - just build a sump "gasket" out of 12mm plate and use 8mm hitensile bolts to hold it in place instead of the factory 6mm used to hold the sump on.

dowelling removes even more metal from the area it's trying to stop from cracking in the first place.

ah sh1t - now you've got me started again...

No, it was Series 2 boxes that I have used, and am not a fan of their shifting or strength(unless by some freak coincidence, all the ones I've used have been stuffed).

As for the 12A turbo 5-speeds, the only one I've come across (or thought I'd come across anyway) was one that came attached to a mates import 12A turbo engine. It was pretty good on shifting, and lasted while the 12AT was in there, but broke pretty quick when he changed to 13BT. I always assumed that because it came on a 12AT engine it was a 12AT box. I wonder what type it actually was?? If it was an RX5 box, it never jammed, which is rare apparently.

And yeah, I've always wondered what an EFI PP would drive like, as I was contemplating one. They still sound just as lumpy, I know that much, but I thought they would still be a bit of a pig to drive. I've never talked to someone who's driven one, so I'd love to hear what you think.

12A turbo boxes were 95% auto and japan only.

finding one is harder than finding a manual soarer box. chances are the manual "12A turbo" box is an aussie spec 12A bellhousing with a last gen 13B RX5 5 speed bolted up.

would account for the "horrible shifting" as the 13B RX5 5spds ALWAYS jam in third under hard changes - ALWAYS. flat changes into second would end up with a nasty crunch as the synchros failed.

and cheers for the info there D. i'm not into falcons too much and like a lot of people i guess i have formed an opinion based on one model - sorry

and a "street PP" would be EFI which eliminates a lot of the jerking associated with big ports and cruising RPM. or you can use a 4spd behind it and drive with a 3speed + overdrive (ie keep it in 3rd).

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Exactly....in a race car it only has to endure one launch per race, and its not usually as hard as a drag race or being a d*ickhead and doing burnouts and stuff, and then the rest is smooth (or its supposed to be anyway).

In a street PP, the drivetrain is constantly jerking due to the PP characteristics, and is the cause of a lot of breakages.

Now lets face it, I enjoy getting my cars out on the track and 'trying' to be fast and smooth, but going to car shows and doing massive burnouts, drag racing and generally abusing machinery is also fun. And I can vouch for the strength of the series 4 turbo box in these high hp and "machinery abusing" situations.

But at the end of the day, a series 1 or 2 box is going to be fine for a single rotor engine, and might be a better choice in this example as it is smaller and lighter (S4 turbo is one big heavy mutha of a box and would be a nightmare to fit in a 1000).

By the way D....I still can't get that link to work you sure its right?

the ea t5 sucks but the T5 from the later falcons and mustangs have some of the best ratio setup available.

The s1 and s2 gearboxes are stronger than 60a datsun boxes. In a 12app rx7 1978 with 10 inch rears and 8 fronts full le mans bodykit the box held very well also. It all depends how you drive as most idiots today enjoy massive burnouts and abusing machinery instead of learning how to drive efficiently.

The supra box ratios are 3.285, 2, 1.4, 1, .78. Not too bad and handle torque from clevelands and other torque monsters.
The Mazda gearboxes turbo or not leave much to be desired in hi hp situations.

Trust me, even a mildly worked 12A turbo will chew through series 2 boxes. And noone can tell me different because I have seen it. And also trying to shift quickly is a nightmare.

Honestly, there's no need for supra boxes or anything, I have had no probs at all with series 4 turbo boxes. They have a nice smooth shift, and I have put heaps of power through them (430rwhp) and given them absolute hell, and have not broken a single one.

And sorry, yes I am incorrect about the series 1 and 2 turbo boxes. What I meant to say was 12A turbo boxes, which are series 3.