cosworth vs rx7

[jazraymcbeath]

hi i am seriously thinking of selling the cossie to get an rx7 but i am getting put off by tunnig cost and petrol consumption and reliablity can you give some facts and figures

to compare my cossie is detunned to 286.3bhp with 279 lbs of torque  and weighs 1240 kg with the gtech meter i can get 0 to 60 in 4.81 sec and quaters in 12.9 sec and with stage 3 0 to 60 in 4.51sec and quater in 12.02 (and enough to do away with a p1 scoobie and  600 bikes) i can put in  10 pound drive sensible and get 70 to 80 mile if driven hard will get 40 miles to my tenner and petrol here is 92 pence a litre the car was running stage 3 about 340 to 350 bhp (conversion cost about 600 pound) but took of as was off as was skint that month and was only getting 26ish miles to 10 pound as the car is driven hard more than sensible i use my car everyday it needs to be reliable and the cossie is that i have had 6 now there that good

how dose the rx7 compare to above as want to try an rx7 but dont want to sell the beloved cossie and be dissapointed i would want the same sort of performance as above but if this cost more than 1500 pound to get that performance and reliablity i  would prefere buying a cossie engine for 1500 and sticking that in and having reliable power in a very pretty cossie powered car as no one knows what a cossie is anymore but when i am driving my girlfreinds integra type r you get plenty of attention

thanks
jaz

[iaint]

If you have to ask what mpg you\'re going to get from a tuned FD then it\'s not the car for you.  Simple as.

If you get past the fact you\'re looking @ 14-20mpg depending on how/where you drive then you\'re (in my biased opinon) looking at one of the best cars you can get for reasonable money.

You don\'t mention budget and that\'s the real thing that\'ll limit the quality and state of tune you\'ll get.

- You can get a stock car and mod it which is the expensive option but you know how well everything has been done.

- You can get a modded car imported. Cheaper than modding yourself but you don\'t have the full knowledge of the car.

- You can buy a decently tuned, rebuilt example from a club-member and know exactly what you\'re getting.

In terms of mods and power it\'s a varied bag.

You can uprate intercooler, fuelling, rad, etc. but keep the standard twin-turbos and get upto around 350-400fwhp or you can go single-turbo and get 350-500 fwhp.

Personally I\'d be looking to get something with a recent rebuild or a dead engine and factor the cost of rebuild into the price for peace of mind.  you could buy a higher mileage car and it might well last another 20k+ though.  The rotary engine isn\'t all that unreliable!

Get along to a meet and talkto a few owners - always the best way to find out a bit about the cars...

[MikeLMR]

if you want cheap power an rx7 isn\'t probably isn\'t the car for you.

as for fitting a cosworth engine for £1500 ?! I\'m not even sure it\'d fit due to the steering rack being high on the rx7s + its going seriously screw up the handling due to the weight of what is basically a 16v turbo\'d pinto.

[MillSpeed]

There\'s no doubt you can get some scary power out of the baby rotary, but I think it\'s widely accepted that 7\'s are expensive to maintain, expensive to run & are a handful to drive! But they are so much fun. I think alot of the 3rd gen\'s bad rep has come from people just not looking after them properly and treating them like a piston engine. The rotary can be built to last, it just takes a bit of planning and, most important of all, proper tuning on a rolling road by a rotary specialist. The car left the factory with a lot of compromises (i.e the cooling system and rediculously complicated sequential turbos), all of which can be improved upon. Can an RX7 be used as a daily driver? I certainly think it could, just with a bit of groundwork to address some of her \'issues\'.

[jazraymcbeath]

a budget of about 5k i am a mechanic to trade so was looking for a car needing work but what i am getting at is i dont mind rebuilding the rotary engine and looking after it as long as it dose not turn round an sting me if the rx could acheive 14 to 20 mpg i could live with that what sort of lsd dose it have and when it starts to oversteer is it progressive or dose it snap

 but dont no if i want to take a chance with the rotary when i could of stuck in a cossie lump as i have seen a pinto in a  mk1 rx7 and rover v8 and american v8 so surley a cossie with a modded sump if need would be a simple fit

[Top_gear_towers]

From reading your post, I think mpg is important to you. That you detuned your Cossie to get better mpg says, to me, you should rethink an RX7 purchase.

No doubt this will be frowned upon, as the larger the club is the better - but I can only speak for myself.

The MPG on the RX7 is nothing short of depressing. I seem to forever be in a petrol station, and my wallet has definitely taken a hit from the monsters constant Optimax thirst.

Around town is not bad at all - but once you hit the motorway on  a long trip, prepare to start looking for Shell stations from the start.

I drove from London to Birmingham and back in my E46 3 series, and used a little less than 1/4 tank.

Did the same trip in the Rex and used an entire tank (and I wasn\'t driving like a loony).

Take as read the RX in an amazing drive, and turns heads like little else.

But once you\'ve put it to sleep and the lights go out, its just you and your wallet baby.

[iaint]

Originally posted by jazraymcbeath
a budget of about 5k i am a mechanic to trade so was looking for a car needing work but what i am getting at is i dont mind rebuilding the rotary engine and looking after it as long as it dose not turn round an sting me if the rx could acheive 14 to 20 mpg i could live with that what sort of lsd dose it have and when it starts to oversteer is it progressive or dose it snap

Could be wrong but I think it\'s a Torsen lsd but my memory may be playing tricks on me there.

In oversteer it\'s very, very progressive indeed - if I can catch tail out moments then it can\'t be that bad.  A heavy right foot in the wet though and you\'d better be sure you know what you\'re doing and autumn/winter always sees a spate of posts from people who\'ve stacked their rexes!

Not sure how it compares to other rwd motors though - from talking to people it\'s the transition period where the secondary turbo comes online that catches many people out - a hike of 100+ ponies over a few hundred rpm can do that if you\'re not used to it or not concentrating!

As you\'re a mechanic you should be able to do most of the work on your car - there\'s a vid doing the rounds that shows you how do rebuild the engine.  The only really complex part of the FD is the turbo control mechanism (\'rats nest\') but this can be simplified by going non-sequential or single turbo.

As for the conversion options - don\'t - you\'ll spend more doing it than a rebuild or two and you\'d be missing out on the thing that really makes the FD shine.

[MillSpeed]

The RX7 is fitted with a torsen LSD as standard. I think alot of the people on this forum will testify that the 7 will stick like sh*t to a blanket, but when she goes...she goes!
A Cossie lump in a 7 would definately be interesting, give it a go and see what happens! Don\'t froget to take lots of photos.

[jazraymcbeath]

what sort of money should i expect to pay for a rex in need of engine rebuild and where do i get my hands on this video on rebuilds what mods are there if starting with a clean slate for a strong reliable engine are the stock radiator and intercooler up to the job cause if you uprate the intercooler you are taking away from the radiator as ther is such a small open surface are at the front of the rex

[MillSpeed]

In my opinion, the stock intercooler is woefully inadaquate...it\'s tiny! But like you said a large front mount will restrict your airflow throught he rad. I\'ve just bought a large PWR charge cooler, and I\'ll be moving my battery to the boot so you can sit the rad more upright and hopefully get some more flow through it. With any luck, the heat exchanger up front will restrict the airflow less than a FMIC. Gonna fabricate some proper ducting too, to make sure all of the air that goes into the \'mouth\' actually goes through the rad. You can buy uprated aluminium rads which are much thicker and will mount in the stock location. You might also consider changing the cars nose. I\'ve got a FEED Type-II front and the radiator opening is much bigger.

[rxv8]

i say DO IT..stick a cossie lump in there would be real interesting..i am pretty sure it would fit no probs,i have a sbc 5.7 in mine and theres plenty of room...pm me if ya want a chat...or pm me ur msn address...cheers:wave

[gsb876]

I sold my Skyline and Escort Cosworth to make room for the RX7 and do not regret it, Cosworths are great cars but the rx7 is so different to drive and handle its worth the jump, if you are not bothered about a rebuild there are plenty of low cost rx7\'s open to you, i think the rebuild kit is £1500 and i\'m guessing you will be doing the rebuild yourself.

[John Yorke]

Hay Mate

To be honest you are not interested in a rotary, best thing you could do is go and buy an engine to fit in yer cossie, why buy a rex and fit a different engine:confused: :confused: Waste of time:reallymad

[jazraymcbeath]

yes will be rebuiding myself and cant wait till get a wankle in bits(if sticking with the wankle)
since you had a cossie (what type and state of tune) we can use that as a bench mark for handling acceleration top end etc how did it compare

[rx7veilside]

i had a 3 door running high stage 3 and it pulled nice but in comparison the difference was between ur perception as a small car will allways seem faster but i wld have to say a moderatly tuned 7 will dump all over the cossie on the street due weight proportionate to power and a highly tuned 7 is quite frightening and not to be abused or it will bite ur arse..looks wise the 7 gets u stopped at lights and people asking what it is