Rear end options for more power? (With UK Parts)

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gt_james
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Re: Rear end options for more power? (With UK Parts)

Post by gt_james » Fri Jan 24, 2020 12:38 pm

what 13B NAs do you have? a 13B 6 port with a weber should be making 165-170hp. A renesis can be made to run on a weber too, again making 170 maybe more, and theyre cheap. If it was me wanting to do it on the cheap I'd just build the engine you have with as many used parts (but within spec) and run it on a weber. Any engine swap will cost a lot more, by the time you've got a K20 running in an FB you'll have spent a lot more than a rebuild kit!

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Re: Rear end options for more power? (With UK Parts)

Post by rotarypower » Fri Jan 24, 2020 3:53 pm

They're 6 ports, one of the sets of rotors is useless, they've been opened to 3mm (which itself would be fine) but they've also had some bad damage & scoring to them. Other set of rotors are good apart from a stuck side seal ( need to get out. (its broken off inside the groove ).
Housings are generally good IIRC if not perfect and plates also good, one has a chip near the port & it needs to be checked to see if its close enough to get away with dressing it out.

But I also have all the ancillaries that go with the engine as well, intakes, etc.
So if I went that route then I'd most likely go EFI, I even have a FFE trigger wheel & sensor so I could run it without the distributor. (Although I have a couple of those as well)
Could run it on something like a microsquirt which would be the same price as a carb if not cheaper. Sure I'd have to learn how to tune it, but the same is true of a carb.

I guess you prefer carbs then? I've had both over the years & its always been the cars / bikes with carbs that are the most finicky and temperamental. Generally EFI just works, though to be fair the only time I've ever been stranded is when a cambelt broke, which could happen to either. (Although not a rotary i grant you)
I've heard a lot of people have streetability problems with the carbs on 13bs. Great top end, but drives like rubbish low down, blipping the throttle to keep it running when cold etc.
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Re: Rear end options for more power? (With UK Parts)

Post by gt_james » Fri Jan 24, 2020 10:36 pm

Well you could convert to EFI, but when you say EFI just works, thats not really true of going megasquirt. Carbs with streetability problems just comes down to tuning, same is true of EFI, its only as good as the tuning.

Either way, 13b would be a better fit for an RX7!

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