Rotary turbo engine???
Rotary turbo engine???
Author
Discussion

GIMPTON

Original Poster:

213 posts

293 months

Friday 29th July 2005
quotequote all
Anyone tried a rotary engine(turbo rx7 one) in a kit?

Any good? what are the pros and cons, apart from the mpg and the tip wear issue.

Cheers

GIMPTON

Original Poster:

213 posts

293 months

Friday 29th July 2005
quotequote all
meant too add how do they perform against more modern engines?

Mikey G

4,850 posts

263 months

Friday 29th July 2005
quotequote all
Performs very well from what i know, not sure on the weight of the things though! i have seen one in an escort years ago and the only problem was cooling and fuel consumption.....

cptsideways

13,831 posts

275 months

Friday 29th July 2005
quotequote all
They don't weigh much at all, don't worry about tip wear in something that wont be doing many miles.

Might be an issue with fuel consumption though & a small tanl, also cheap tax!

Mutant Rat

9,939 posts

268 months

Friday 29th July 2005
quotequote all
I've seen a few naturally aspirated rotary engines in kit-cars (A Sylva, a Noble 23 and an Eldon Roadster particularly come to mind), but none with a turbo.

The naturally aspirated versions work well - the engines are very compact and so can be set very low and far back, for a low centre of gravity and good weight distribution. From talking to the guy who built the Eldon, I gather that the engine isn't particularly light though - it may be compact but there is a lot of metal in it, so it is fairly 'dense'.

I'd have thought that enough RX8's are now being crashed to make the new 'Renesis' version of the engine a better bet than an old Series 2 RX7 Turbo unit? 237bhp straight out of the box, 6 speed gearbox and no faffing about with plumbing in the turbo and intercooler?

andygtt

8,345 posts

287 months

Saturday 30th July 2005
quotequote all
I'd say the combination of low torque and high revs would be ideal for a lightweight kit car.
my understanding was also that these engines are lighter than conventional piston engines.

ERP

25 posts

306 months

Saturday 30th July 2005
quotequote all
They are lighter, but not by as much as a lot of people think.

The real advantage of these engines is the packaging, as was mentioned earlier they are very compact.

Having owned a twinturbo RX7 I can say the engine was stellar when it ran. I can only imagine what the acceleration would be like in a car weighing close the 1/2 as much... Mine was a 93 and the most unreliable car I have ever owned I blew 3 turbos and had the oilpan gasket replaced 5 times along with miscellaneous other problems in the 2 years I owned it. Having said that I've heard there are good and bad 93's and the 94/95 and later (if you go JDM) had a lot of the problems ironed out.


GIMPTON

Original Poster:

213 posts

293 months

Sunday 31st July 2005
quotequote all
Thanks for the reponse's

Heat was another concern of mine, would it be a lot more that the ZZR1100 lump i presently have behind me? as that seems to kick out about the same as my old V8s.

Aeon, the new owner of my kit the old Pell Genesis,suggest the 1.8t lump but it is a bland soul-less lump and getting it to a decent power level 230-250+ is not too cheap, not much in the way of revs and my main concern a lot of torque in a mid engined kit.

So just looking at other options and having driven a couple of RX7's a few years back and believe would be a great lump in a lightweight kit, not too much torque and a good rev range.

andygtt

8,345 posts

287 months

Sunday 31st July 2005
quotequote all
if there is a bike engine in there already stick with it and upgrade it, turbocharger kits are available for bike engines.
my mate is making a kit for his bussa engine that takes it to over 350bhp!

cptsideways

13,831 posts

275 months

Sunday 31st July 2005
quotequote all
RX8 engine would be a better bet

GIMPTON

Original Poster:

213 posts

293 months

Sunday 31st July 2005
quotequote all
Bike engines are great ..... for the track

Most of my time is spent on the roads, only get to do 2 trackdays a year tops.

Also the Pell/Aeon weighs 680kgs far too heavy for a bike engine maybe apart from 1500cc busa with a turbo, and i only have around £5-6k to buy the engine and get it fitted. The fitting is around £1500 so that leaves me with £3.5-£4k for the engine.

busa_rush

6,930 posts

274 months

Sunday 31st July 2005
quotequote all
GIMPTON said:
Bike engines are great ..... for the track


Tell me, why do you not consider them suitable for road use ?

GIMPTON

Original Poster:

213 posts

293 months

Sunday 31st July 2005
quotequote all
The reasons are A: want to make it more usable on a daily basis, so car engine is much more civil and better in traffic.

B: as stated most BEC's weigh a good deal less than 680kgs and with a N/A engine 95lbs torque is not enough, pull away quick enough but my misses in our Integra type r leaves me standing past 90mph. Not that i go over 90mph officer!!!.

Looked into a turbo kit for the ZZR1100 engine some time ago but don think it would last to long with daily use.

Mutant Rat

9,939 posts

268 months

Sunday 31st July 2005
quotequote all
GIMPTON said:
Heat was another concern of mine, would it be a lot more that the ZZR1100 lump I presently have behind me? as that seems to kick out about the same as my old V8s.


Broadly speaking, heat is directly proportional to power output.

There isn't a huge amount of difference between the efficiency of petrol engines at converting the chemical energy of petrol into horsepower. Assuming, for the sake of argument, that you are going to get about 70% efficiency, then the other 30% turns into heat...simple as that.

The only significantly different situation is a turbo engine, because waste heat which on a normal engine would be dumped straight out of the exhaust is instead transferred back into the system because it is re-absorbed in the turbocharger.

A bit of an oversimplification, I know, but basically your cooiling system has got to be proportional to the power output of your engine, no matter what type of engine you fit.

busa_rush

6,930 posts

274 months

Sunday 31st July 2005
quotequote all
GIMPTON said:
The reasons are A: want to make it more usable on a daily basis, so car engine is much more civil and better in traffic.

B: as stated most BEC's weigh a good deal less than 680kgs and with a N/A engine 95lbs torque is not enough, pull away quick enough but my misses in our Integra type r leaves me standing past 90mph. Not that i go over 90mph officer!!!.

Looked into a turbo kit for the ZZR1100 engine some time ago but don think it would last to long with daily use.



You've got gears ?