Racing an RX

[TonyC]

Hello all, I\'m currently tying to decide on a new race car project and I\'ve narrowed it down to either RX7 or Supra. At the moment I\'m leaning towards the RX7 as it\'s lighter and the base car to buy is cheaper than a twin turbo supra. But I\'ve a few questions and I\'m hoping someone can point me in the correct direction.

Firstly, I know the championship and regs so I know what I can or can\'t do in terms of modifications. I\'ve also built a succesful racing car before and I\'m a professional motor racing instructor working for companies such as Caterham and driveme.net

I need some information on the cars themselves.
What is the weight of the standard car. I\'d like to get the car down to 1100kg(or less?) - I\'ll be removing door glass,motors, interior, etc. Is this realistic, and is the rear hatch all steel and glass - as the glass in the hatch strikes me as being potentially the heaviest item and as it is compound curvature - difficult to replicate in perspex.

Is there a particular  (type R?)that is better to choose as a base car? I\'ll be selecting my own coil overs and brakes so what is on the base car should not matter.
Do all cars have the same LSD?

To make the car competative, at the weight I\'d like to hit, I\'ll need around 320-350bhp (flywheel). What mods do the engines need to get near this figure - is it major internal work? I\'d prefer to keep sequential turbo\'s as in theory this will keep the car more adjustable on the throttle - compared to a laggy single unit.
Also, would there be any companies in the RX7 world that may be interested in this project and may be able to offer support advice or other services, with a view to me providing advertisment space on the completed car?

Thanks all and I\'ll have lots more questions I\'m sure soon!

Tony

[Adriansturgess]

Firstly welcome to the club, it sounds an exciting project. The type R has twin oil coolers and so would think a good base for your project. I think the Rex weighs in at around 1300kg standard but depends on exact model. I would have thought you could get it down to 1100kg. Stock twins should see the kind of power you are looking for but will leave it for others to describe best way to get there. It may be worth checking out some of the vendors at the top of this page in terms of some kind of sponsorship arrangement.

Edit - just noticed you are quoting flywheel bhp - relatively minor mods should easily see this figure attainable with good reliability too.

[TonyC]

excellent stuff, thanks. Stuff like twin oil coolers is useful to know- that\'s the kind of thing that helps with a project like this. The races are standard 20 minute or so UK club racing affairs, not the 3 hour British GT jobbies.

Just a quick cheeky question as well - I could do with seeing a car in the flesh and a kind owner letting me have a close look (under bonnet, boot, etc). Even take me out for a quick ride as it hels a lot in my understanding of a cars potential (I\'m used to evaluating cars from the passenger seat due to my race instruction work).  I\'m in Skipton in N. Yorks and I\'m not a stalker or car napper!  Or is their a local meet I could pop over to?

Tony

[Rixio]

Hi Tony,

With regards to weight -1100kg is going to be a push as A7NTY has totally transformed his interior and it weighs in at 1150 or so iirc...im sure he will correct me if wrong

The RZ is the best model to start with because it was built with stronger bits and bobs cant remember the particulars but i know it has a stronger Diff 1.5 way LSD and other bits...

Getting 350fly hp isnt going to be costly but if your going to race the car proffesionally then i suggest you get a race built engine...Carl Hayward does these for £5k and with a full race warranty aswell you cant go wrong...i dont know about regs for that sort of stuff but he\'l be more than happy to help out if you give him a buzz...

Mods wise a decent rebuild with porting should easily see you 310-350fwhp with the following mods:
Intake Kit
Full Exhaust System
Front Mount Intercooler
Larger Injectors
& a stand alone fuel management system...

Hope that covers everything & welcome to the forum

There are a few cars in the area & im sure somebody would be willing to oblige, if mine was running then you could come roud and take a peek, if it doesnt make a difference then my offer still stands

[RemarkLima]

Hi Tony,

Just curious really but what series are you racing a RX in? I\'ve just finished a season in the MR2 Challenge and there was a RX7 racing in the Roadsports but that\'s about it...

But isn\'t a R2 weight in at 1240 kg? So down to 1100 kg should be too hard for an out and out racer, no interior except one seat and runners, no air con, FRP bonnet, I\'ve seen FRP rear hatches about as well, there looks like there\'s plenty to loose really.

Thanks,
Mark

[TonyC]

Hi, yep roadsports is now defunct sadly, but the DDMC run a championship with several classes and the RX7 will fit into that. I already have a friend racing a 520bhp MG ZT V8 in this championship. I know the lap times and the circuits and know my curent laps times with my current car - hence my estimates in weight/power to get a car competative within that championship.

Really useful info on the engine - from the sound of it it should be possible to get more grunt that expected. Always good.

Rixio, a non runner would still be useful so I may take you up on the offer if thats ok.

How did you find the MR2 challenge - I had a Mk1 Mr2 for a year and thought it a great little car -it had rusted away in a year though - I always thought it a brilliant little handler, better in many ways that a Mk1 Elise. The only thing I found with it was that you had ot be fast and accurate to catch any oversteer. Keeps you on your toes!

[RemarkLima]

Yeah, the roadsports has been dying a death this year sadly... And without it the MR2 challenge would have never happened!

I\'ll definately keep an eye on that, looks very interesting! 520bhp should be "enough"

[Rixio]

No probs...you can give me a call on 07886 208 395
Id be interested to hear about the racing etc because its something iv been thinking of going into but not known anything about :o

[TonyC]

Aye, 520 is a lot, but they are stuck on the weight. They have stripped and carbon fibred but the old bus is still over 1400kg ( not suprising given the road car is 1800kg - I\'ve got one!) Varied racing though, just what I like.

Will do rixio, speak to you tomorrow at a more earthly hour. Happy to chat about racing. I\'m a licenced ARDS instructor so I\'m one of the guys that decides if a driver can have a race licence.

[Red and Single]

What modifications are you allowed and not allowed to do to the car ?  

500 - 600 bhp is easy if your allowed to change turbos and fuelling...

Anty is selling his track prepared RX at the moment might be a cheaper route to what you are after.....

I cant link to his ad but I\'ve stolen the text.....

..................

Is with a heavy heart I make this post.

1993 December – Mazda RX7 type R2

1100kgs (weight down from 1250kgs)

The car currently runs an HKS TO4Z single turbo and makes 400bhp at the wheels at 1 bar boost on pump fuel, 435 at the wheels at 1.2 bar. 1.4 bar would I suspect be around 470 at the wheels.

The engine has made more power, with a T51R turbo;
527 bhp at the rear wheels using 1.4 bar boost and 120ron race fuel
(equates to approximately 620bhp at the flywheel) But this was at the expense of low down power.

The vehicle still holds a record;

Fastest RX7 over 1.25 miles in Europe with 183.3mph – genuine 200mph capability

I still believe with the T51R it is the most powerful 13B REW engine dynoed in the UK.

This car has also featured in various issues of J-tuner and was the the cover feature on the very first issue. I will give the new owner a copy (never even opened or read) for prosperity.

The car is set up for track and sprint use. We have run it up the strip, but with the suspension set up, stiff sidewall tyres and gearing its never going to be the fastest up the strip. Fastest time set so far was a 12.2 although we reckon it did an 11.9 but never got the slip to prove it.

Here is the vast list of modification;

Engine/Cooling/Exhaust modifications:

RX Motors bridge ported engine,
Trust front mount intercooler,
Trust hard piping,
Trust inlet plenum,
Trust twin oil coolers,
HKS T04Z,
Greddy manifold,
Greddy down pipe,
Trust ‘type R’ wastegate,
Trust pulley kit,
Section engine damper,
RE-Amemiya large capacity radiator.
FEED exhaust mid pipe,
Blitz Nur spec catback exhaust or Fujitsubo quiet catback exhaust.

Electronic/fuelling modifications:

Power FC ECU with commander unit,
550cc primary injectors,
1680cc Bosch secondary injectors,
KGP fuel rail,
Aeromotive fuel pressure regulator and fuel lines,
VDO fuel pressure gauge,
Nismo R33 GTR fuel lift pump,
2x Bosch 044 scavenger pumps,
Custom Tomei swirl pot,
Greddy profec B spec II boost controller,
Greddy water temperature gauge,
Greddy oil temperature gauge,
Greddy oil pressure gauge,
Greddy EGT (exhaust gas temperature) gauge,
Greddy boost gauge,
SARD attack meter,
Tech Edge wide band air/fuel ratio gauge and kit,
Uprated plug leads,
NGK racing spark plugs (10\'s leading, 11\'s trailing),
HKS twin spark amplifier,
Battery relocated to rear of car,
Start ignition switch in dash,
RE:Worx water injection system .
Aquamist water injection flow gauge.

Brake modifications:

AP Racing 4 pot front callipers,
Projec Mu slotted discs,
Electronic line lock,
Ferodo DS2500 brake pads,
Braided brake hoses,
Master cylinder stopper brace.

Interior and Chassis modifications:

Custom aluminium door panels,
Custom Aluminium dashboard,
Recaro reclineable seats (x2),
Cusco front strut brace,
RE-Amemiya under car chassis brace,
Rear strength bars,
Rear roll cage to comply with sprint regulations,
Autoexe front and rear chassis braces,
Racing beat front and rear uprated anti-roll bars,
Racing Beat front anti-roll bar support bar,
Ohlins Coiloveradjustable suspension,
Fully stripped and lightened interior with no sound proofing,
Momo Steering wheel on a modified steering column,
Mazdaspeed gear nob,
Mazdaspeed quick shift kit,
2x Sparco Racing 4 point harnesses with Trust covers.

Gearbox/drive modifications:

OS Giken Twin plate clutch (needs an overhaul kit to be used again)
Now fitted with an Extreme single plate clutch,
3.9 LS rear diff for top speed,
4.1 LS rear diff for drag/track,

Exterior modifications:

C-West front bumper,
RE-Amemiya side skirts,
GT Atyle rear wing,
RE-Amemiya carbon fibre rear diffuser,
BBS LM 18" Alloys, 265 width rear tyres and 225 width front Dunlop Do1J tyres.
Dare 18" wheels with Pirelli P-Zero 225 width slick tyres.
Also a full set of Avon ZZ3 wet weather tyres.
Scoot vented bonnet (original not a poor fitting copy)
Ganador wing mirrors,
C-west Sleek headlight conversion,
Tinted rear window.

The car has had so many oil changes it would shock most! normally changed with a new Mazda oil filter using 10w40 76 racing mineral oil every few HUNDRED miles at most. It has had all the rear suspension bushes replaced. The clutch is not even fitted yet so is brand new (will be fitted in the next few weeks).

This is an awesome car in every respect, mind blowing acceleration, brakes and handling. It would terrify most including me many times!

Of course we will have the decals removed for the new owner professionally and will carry out any paint repairs as necessary to get the paint to a1 condition. The car will also be fully serviced before sale and will come with a years MOT and 6 months road tax.

I have literally hundreds of photos of the car and will endeavour to get some posted up here as soon as I have selected some good ones.

The price is as you may expect high for a car like this, but considering the huge amount spent on the car its more than fair.

We will continue to use and enjoy the car until its sold, we are in absolutely no rush to sell and will hold out for the right price so please dont even bother with silly offers, the answer will be no.

Offers in the region of £20,000+

[gsb876]

Anthony\'s car is a very decent one hence the price, but you can get a rebuild rx with a single turbo conversion for under £10K nowadays and then do what other mods you need to do to make it competitive :cheers

Ants car:

[TonyC]

Thanks for the info fellas, but I have quite a clear idea of what it is I need to put together and what it needs to be in drivability terms. It is very easy to get carrired away with power on these kind of cars - but what I need is a balanced packaged. Hence me looking at what I imagine a large number of people feel is modest power.
Thanks also for the offer of already modded cars but I am a bit of a control freak and like to make my own selections in terms of suspension mods, etc - I intend to pick up a cheap plain RX7 direct from Japan (as I do not need it Uk registed - it can arrive at the docs and then it\'s back home on the trailer to be preped), strip it and work from there. (Also, the 20k would not be eligible for many race championships  - and certainly not the one I\'m looking at - as the ad says it needs 120RON race fuel. Most UK championships at club level require you to run normal pump fuel. IE: Optimax or similar will be the highest octane you could use (with Millers added)

It may seem an odd way of doing it with so many big power RX7\'s for sale, but I\'m sure you\'ll be excited by what I produce.

[Red and Single]

Thanks for the info fellas, but I have quite a clear idea of what it is I need to put together and what it needs to be in drivability terms. It is very easy to get carrired away with power on these kind of cars - but what I need is a balanced packaged. Hence me looking at what I imagine a large number of people feel is modest power.
Thanks also for the offer of already modded cars but I am a bit of a control freak and like to make my own selections in terms of suspension mods, etc - I intend to pick up a cheap plain RX7 direct from Japan (as I do not need it Uk registed - it can arrive at the docs and then it\'s back home on the trailer to be preped), strip it and work from there. (Also, the 20k would not be eligible for many race championships  - and certainly not the one I\'m looking at - as the ad says it needs 120RON race fuel. Most UK championships at club level require you to run normal pump fuel. IE: Optimax or similar will be the highest octane you could use (with Millers added)

It may seem an odd way of doing it with so many big power RX7\'s for sale, but I\'m sure you\'ll be excited by what I produce.

No worries, just a thought (btw Ant\'s car doesn\'t "need" 120 ron fuel, just makes more ponies with it...).

Can you give us a simplified list of the rules and regs regarding this championship, it sounds very very interesting indeed !!

[sadgoth]

I suspect you could pick up an early stock car for not a lot (especially if you are stripping it so interior condition isn\'t an issue. I\'d say your best bet would be to go for a 60k+ miles car without a rebuild for next to nought then get a race engine built by Carl Hayward.

[RE:Worx]

My Drag car weighs 1080kg with 60kg\'s of cage It takes alot of work to get the weight down this low without compromising the chassis, As for Racing they make excellent circuit cars.

most of the RX\'s we have put on corner weight scales. have almost 50%split and 50% cross weights as well so well suited to racing

Geff