www.RX7fb.com

I'm using it as a daily at the moment so I don't want to do anything to it that might cause it to go off the road... I've got loads of projects lined up for it over the winter.... the back axle will be changed when I fit my full kit of polybushes.... I've got the Elford front spoiler to go on and if I get the parts I want off Tools 12at, I'll have plenty to be going on with.
I've wanted to do a 13b conversion for 20 years but I also like the simplicity of the 12a setup with the Elford on it....
I don't know whether to tear down one of my spare 12a's, get it ported and then try to increase the boost with some water injection, a bigger exhaust and a manual boost controller... How far do you reckon I'd get the power up on a fresh 12a engine??? They were good for 160 standard .... it'd be nice to push it up towards the magical 190 which, as you say taking into account the power to weight ratio, would make it fly.
I like the idea of the 2nd gen subframe swap as well but the steering column worries me.... I don't want to do a Senna.

I'm really enjoying driving it now.... on the standard 12a, it couldn't keep up with a modern diesel.....but the turbo has given it the edge again... it's a quick little car for a 27 year old motor.... the handling is dire though.... it needs those polys and some new springs fitted.
I'm just collecting parts as and when at the moment .... and the bloody XJR is still bleeding me dry. I was going to sell it but after discussing it with the wife, neither of us want to sell it given that all the major work has been done to it and we've had to spend a fortune on it.... so I might as well sort the last few things and then keep it rather than let someone else have the benefit of it all.... I'll get it sorted then I can go back to spending on the fb again

ian65 wrote:How far do you reckon I'd get the power up on a fresh 12a engine??? They were good for 160 standard .... it'd be nice to push it up towards the magical 190 which, as you say taking into account the power to weight ratio, would make it fly.

You should speak to Tim at RX Motors. If I remember rightly a few years ago he ran 250BHP 12at, followed by a 325BHP 12at... (then a 600BHP but that was a 13b) and has done a fair few conversions for customers.

(But don't forget what it will do to the fuel consumption...)

John

well its like everyone says you never get your money back on a car.
unless its an e-type lol. seriously its just a case of spending to get enjoyment out of the cars.
if you've put so much into the jag then just save up and finish it and you and your wife can enjoy the car.

they are great jags, even when i was 6/7 i loved the white xj6 we had, cream leather and pas, elecy windows, power locks etc
you really felt like royalty in it. even the head master came down to see who was driving it when my mum drove up to school.

she drank it though lol and the autobox started to give trouble. she ended up a few miles away and i used to see her parked up driving into town
with my father. oh the big cat on the bonnet and the twin tanks lol, can't beat that

Johnnyboy wrote:

ian65 wrote:How far do you reckon I'd get the power up on a fresh 12a engine??? They were good for 160 standard .... it'd be nice to push it up towards the magical 190 which, as you say taking into account the power to weight ratio, would make it fly.

You should speak to Tim at RX Motors. If I remember rightly a few years ago he ran 250BHP 12at, followed by a 325BHP 12at... (then a 600BHP but that was a 13b) and has done a fair few conversions for customers.

(But don't forget what it will do to the fuel consumption...)

John

I want the performance .... to a degree.... but I don't want to lose it's driveability. It's finding the right balance and the Elford is good for that.... I suppose I'd just be looking to optimise that and get a few more hp out of it.
I don't want to build a fire breathing monster that isn't trackable around town and usable on a day to day basis.
But the 13b would give me more torque and mappable efi so it's tempting

spoddy wrote:well its like everyone says you never get your money back on a car.
unless its an e-type lol. seriously its just a case of spending to get enjoyment out of the cars.

I've owned nearly 60 cars and most have lost money.... that's the name of the game but this thing is my modern daily driver and although depreciation and maintenance is expected, the amount of dough I've poured into this car in repairs over the last few months has been eyewatering..... there's no enjoyment in enforced spending to keep the thing on the road.
I'm now at the point where the typical faults on these cars have been fixed so I might as well keep it and run it. They are pretty collectable..... it's a modern classic really, only 15,000 were built, most went to the US and the number of them in the Uk still on the road is diminishing.... much like the RX7 really.... plus it's the last of the classic Jag shape which people love, myself included.

ian65 wrote:I'm using it as a daily at the moment so I don't want to do anything to it that might cause it to go off the road... I've got loads of projects lined up for it over the winter.... the back axle will be changed when I fit my full kit of polybushes.... I've got the Elford front spoiler to go on and if I get the parts I want off Tools 12at, I'll have plenty to be going on with.
I've wanted to do a 13b conversion for 20 years but I also like the simplicity of the 12a setup with the Elford on it....
I don't know whether to tear down one of my spare 12a's, get it ported and then try to increase the boost with some water injection, a bigger exhaust and a manual boost controller... How far do you reckon I'd get the power up on a fresh 12a engine??? They were good for 160 standard .... it'd be nice to push it up towards the magical 190 which, as you say taking into account the power to weight ratio, would make it fly.
I like the idea of the 2nd gen subframe swap as well but the steering column worries me.... I don't want to do a Senna.

You'll probably find that the loss of compression in the 12a motors is just as much from flaking chrome on the housings as from worn apex/side/corner seals and springs. There is nothing particularly wrong with a good 12at bar the fact the housings are hard to get hold of. Repairing the chrome is almost as expensive as a new housing, if you could find one.

I'd not bother with WI either for the power you are looking for, an intercooler set up is cheaper and ultimately more reliable and less maintenance.

Getting 190hp from a 12at with intercooler does not require any type of porting either - if that's all you want, then turn the wick up on the current motor. Your engine is low on comp, but the turbo can make up for this by running higher boost and raising the effective compression ratio, without a big impact on engine life - main thing to look out for is heat generated by the turbo as you haven't got an intercooler - if you migrated to injection (there is a microtech for sale on exile at the moment) then the intercooler and 200hp are yours for the taking no engine swap required.

Set the timing right and the engine won't pop, it will just gradually wear out slowly and give you plenty of notice in doing so - when that happens, swap in another 12a runner and you'll be good for a 5 figure milage if you feel the need - or ditch the 12a and drop in an FC subframe and engine all in one hit like I did. Steering column is only hard if there is no one around to guide as to what to do - if I did one again it would be pretty straight forward.

RamoNZ wrote:

ian65 wrote:I'm using it as a daily at the moment so I don't want to do anything to it that might cause it to go off the road... I've got loads of projects lined up for it over the winter.... the back axle will be changed when I fit my full kit of polybushes.... I've got the Elford front spoiler to go on and if I get the parts I want off Tools 12at, I'll have plenty to be going on with.
I've wanted to do a 13b conversion for 20 years but I also like the simplicity of the 12a setup with the Elford on it....
I don't know whether to tear down one of my spare 12a's, get it ported and then try to increase the boost with some water injection, a bigger exhaust and a manual boost controller... How far do you reckon I'd get the power up on a fresh 12a engine??? They were good for 160 standard .... it'd be nice to push it up towards the magical 190 which, as you say taking into account the power to weight ratio, would make it fly.
I like the idea of the 2nd gen subframe swap as well but the steering column worries me.... I don't want to do a Senna.

You'll probably find that the loss of compression in the 12a motors is just as much from flaking chrome on the housings as from worn apex/side/corner seals and springs. There is nothing particularly wrong with a good 12at bar the fact the housings are hard to get hold of. Repairing the chrome is almost as expensive as a new housing, if you could find one.

I'd not bother with WI either for the power you are looking for, an intercooler set up is cheaper and ultimately more reliable and less maintenance.

Getting 190hp from a 12at with intercooler does not require any type of porting either - if that's all you want, then turn the wick up on the current motor. Your engine is low on comp, but the turbo can make up for this by running higher boost and raising the effective compression ratio, without a big impact on engine life - main thing to look out for is heat generated by the turbo as you haven't got an intercooler - if you migrated to injection (there is a microtech for sale on exile at the moment) then the intercooler and 200hp are yours for the taking no engine swap required.

Set the timing right and the engine won't pop, it will just gradually wear out slowly and give you plenty of notice in doing so - when that happens, swap in another 12a runner and you'll be good for a 5 figure milage if you feel the need - or ditch the 12a and drop in an FC subframe and engine all in one hit like I did. Steering column is only hard if there is no one around to guide as to what to do - if I did one again it would be pretty straight forward.

I agree with Ramon. Forget water injection and fit an intercooler. As far as 12A housings go, there are plenty of good used housings about and even new ones (at a price).

The factory 12At at 165hp can be safely increased to 230-240hp by fitting an intercooler and raising the boost. No porting required, with tiny primaries and using the stock injectors and turbo. Great driveability and plenty of power. If you're looking for 200 (ish) you can get this from turboing an NA 12A easily and safely, which is essentially what Elford have done (without raising the boost). Intercooler is the way to go.

The simplest and cheapest way would be to do what Ramon has done and slap in a TII 13B. Or fit a TII intake onto a 12A with an adaptor plate and run whatever manifold and turbo you want. There's lot's of options.

Me, I'd keep it Elford.

loads of great advice there gents..... plenty to think about!

Great thread Ian and as usual great advice from the guys.

My SA is running a 13B at the moment and as I am stripping it down and doing a complete rebuild of the car am thinking which way to go. From what I have read on this forum I think that an Elford Turbo on my 13B would be great, 200+ Bhp is plenty for these cars as an everyday rather then fire breathing monster. I would have to agree with going the intercooler route. I know that the MR2 boys use water coolers but I think that is due to space and struggling to keep the temps down due to the engine being in the boot We don't have that problem so a decent intercooler out front will work a treat.
When I had my 200sx (my first car ) I got rid of the pants wing mounted jobby and fitted a front mounted one from a saab 900, worked a treat. I am thinking of getting hold of one myself just incase I go the turbo route as they are pretty cheap from breakers if I remember correctly. Also not looking for a massive Skyline type fitted to the front lol
Great car Ian, good luck with the project
Simon

RX7SA wrote:Great thread Ian and as usual great advice from the guys.

My SA is running a 13B at the moment and as I am stripping it down and doing a complete rebuild of the car am thinking which way to go. From what I have read on this forum I think that an Elford Turbo on my 13B would be great, 200+ Bhp is plenty for these cars as an everyday rather then fire breathing monster. I would have to agree with going the intercooler route. I know that the MR2 boys use water coolers but I think that is due to space and struggling to keep the temps down due to the engine being in the boot We don't have that problem so a decent intercooler out front will work a treat.
When I had my 200sx (my first car ) I got rid of the pants wing mounted jobby and fitted a front mounted one from a saab 900, worked a treat. I am thinking of getting hold of one myself just incase I go the turbo route as they are pretty cheap from breakers if I remember correctly. Also not looking for a massive Skyline type fitted to the front lol
Great car Ian, good luck with the project
Simon

I think you'll struggle to adapt an Elford setup to go onto a 13b in a 1st gen Simon. The Elford setup was designed specifically for the 12a and the cast manifold won't fit a 13b and you won't be able to use an adapter plate because of the limited space. Even in the standard Elford, the turbo is incredibly close to the brake servo so no room to move it over by using an adapter.
The Elford is a sweet, simple little setup but it isn't easily altered to fit non 12a engines.