Hi all,
I\'m new here and would appreciate anyones opinion / advice on the challenge I\'m undertaking. I\'m planning to fly the Rotary flag in this years Practical Performance Cars (PPC) £999 challenge. What\'s this you ask? Well, basically you have to buy and modify a car for less than £1k. Then \'race\' them against fellow readers at Elvington airfield (York) over a 1/4 mile and a handling / slalom course, the lowest time wins. Simple really. So, I\'ve recently bought a \'90 RX7 TurboII. Unfortunately the car is as rotten as a students fridge, but we have the technology (and mig wire) to rebuild her. Mechanically the car seems pretty good and it has the big bonus of a nice (3") full decat exhaust system, which I understand is critical to make decent power in these cars? So far I\'ve got an induction kit (with loads of cold air feed) and fitted a chip to the ecu that should remove the boost / fuel cut limits and give me mapping up to 1 bar boost. The next step is to fit a proper boost gauge and fit an MBC to \'wind\' up the boost and see what she\'ll do. So, how far can I wind the boost up for this short blast to get maximum performance? We\'re not talking reliability / longevity here, but I don\'t want to \'waste\' boost if there\'s no performance gain. On the handling front (btw- brakes seem ok) I have about £200 left in the kitty. All shocks seem OK (no leaks) so I might fit some poly bushes as the rubber ones are shot, a set of lowered springs and possibly a bit of negative camber on the front wheels if the strut to tyre / wheel clearance will allow.
It\'s all a bit of a laugh, but we\'re in it to win it so any advice (within budget) is welcomed.
Cheers guys,
Nick
TTW rotary rookies!!
PS Anyone want to put first bagsies on the full SS system for when she blows up or falls apart?
Cue Grinder :)
If it can be done on a budget he\'s your man.
Is it a coupe?
QuoteCue Grinder
If it can be done on a budget he\'s your man.
HEHE True that.
Hi and welcome to the club. This sounds like a really interesting project. It looks to me like you\'ve done all the normal stage 1 type mods. (just for the record I ran a 14.1 on my first ever 1/4 mile last year at Elvington) I have a TII with the same sort of mods as you too. Intake, 3" exhaust (turbo back no cat), BOV, manual boost controller (although mine is crap and was playing up on the day). I don\'t think you\'ll get a set of poly bushes and suspension for £200 but you never know you might get lucky. Good luck with it. When is the event? I would be interested in coming to watch.
On all the T2\'s i\'ve aways had some sort of brake issue, check there is no sort of Binding, even push the pistons in and out a few times to be sure. The Four pots on the front are renown for it.
It may be worth your while ringing round a few places like WGT and asking for there advise (may even have a few second hand goodies on the shelf :))
sound like a good project.
let us know when its on and ill take a ride over
matt
Blimey, you guys are quick on the draw!!
Yes, it\'s a coupe and a very \'ripe\' one at that! Although hopefully I\'ve done the lions share of the welding so far.
I\'ve got a set of new Spax springs sorted and have ordered a full poly bush set off US ebay for £60 delivered, so hopefully they\'ll be OK. Just need to see if I can engineer some negative camber into the front wheels then.
Basically I\'m only left with peanuts in the kitty, enough to get her through the MOT. As well as the tuning mods stated she\'ll be going on a diet - if it\'s not needed it\'ll be coming out.
What sort of power can I expect on 1 bar boost if all\'s well?
Cheers,
Nick
BTW - It\'s Saturday 14th June.
The day before my birthday. you got a link to those poly bushes? I will deffo try and get over for the event. Oh and try and save what you can when yo are stripping it out. There are always people after something for these cars as they are getting older and rarer. Enjoy it.
http://cgi.ebay.com/ebaymotors/86-91-Mazda-RX7-Prothane-Total-Suspension-Bushing-Kit_W0QQitemZ300203427037QQihZ020QQcategoryZ42609QQssPageNameZWDVWQQrdZ1QQcmdZViewItem (http://cgi.ebay.com/ebaymotors/86-91-Mazda-RX7-Prothane-Total-Suspension-Bushing-Kit_W0QQitemZ300203427037QQihZ020QQcategoryZ42609QQssPageNameZWDVWQQrdZ1QQcmdZViewItem)
There you go. They do 2 kits, this been the cheaper of them. The other kit is more comprehensive (and slightly dearer) with all nuts / washers / fasteners etc.
I\'ll be keeping all the stripped bits safe until I decide what to do with the car after the event. I may end up keeping it to use as a track car (preferred option!) or may sell it on.
Looks a good poly bush kit, think i got the more comphrensive one as mine came with everything and for the whole car.
This should be an interesting project, sort of thing i would have done a few years back. Strip the car totally and especially the aircon but keep the power steering if you are doing some handling stuff. Put a new set of plugs in it even if they look alright and certainly go for 9\'s all round. is this a S4 or S5 ? basically 1989 onwards will be S5, just asking as the S5\'s have a better turbo and more BHP (200 standard). Dont put any large wheels on, the standard TII alloys are quite light and the tyres will be dirt cheap.
If you have trouble with the front brakes let me know as i have a few sets of calipers sitting around, i\'m just taking off some really good. almost new disks if you need some. I will hunt around and see if i have any pads, got some ceramic ones that eat disks but perfect for you and what you are doing, probably clean the disks up a treat !! Where are you based ? if i can help you out then i will. I have lots of spares for the TII.
did someone call :D :D :D
i love it when people work to budgets - just like me :D :D
the rot in the car will cause you the most probs - its a pain to fix ( click the link in my sig for the website - and have a look under the rust section )
if you run at .9 bar of boost everything should be fine - and why fit a boost controller if you are on a budget - it seems pointless to me
strip everything out of the car - why make it faster when you can make it lighter :D :D - get all the back seats out
if you can - take off the AC and air pump ( should free up a few HP - say 4-5bhp )
the spec of the car - you should be seeing about 230-250 at the fly - so thats pretty good
we need pics and all updates you make to the car though :D
Stu
pdtaylor,
Thanks for the offer of the brakes, top man. The backs seem OK but haven\'t had a real good look at the fronts as yet. The ceramic pads sound just the job though, especially if they\'re cheap!! The car\'s an S5 (\'90) but unfortunately it\'s already been fitted with some 7.5x16 MOMO alloys (225/50 rear 205/45 front) with no spigot rings!! I\'m trying to source some at the moment. I\'d be quite happy to swap these for a std set with good tyres if anyone has any though.
grinder,
Why just make a car lighter, when you can make it faster and lighter?!? ;o) Back seat are out for welding, and staying out.
The boost controller I\'m fitting is the manual (MBC) \'cheap as chips\' variety, not the mega money electronic variety. Is 0.9 bar the max I should aim for then? Can\'t I go for the full 1 bar for this short blast? The chip I\'ve fitted is supposed to give \'safe\' mapping up to 1 bar.
Did they all have AC? I\'ve not even looked, been too busy welding.
Thanks again guys,
Nick
well some did and some didn\'t
i doubt you\' need power steering either :D
Got any pics etc :)
I\'d keep the PS - theres a sprint course IIRC?
With a 3" system and a fuel cut defencer you will see something along the lines of 230-250 bhp (Depending on how well the turbo has survived and the exact nature of the exhaust)
I\'d spend the £200 on a decent set of tyres ;)
Yes, think I will stick with the PS. Could be a long day on the slalom course!!
The exhaust looks / sounds the business, don\'t know what make it is but reciept for £1K came with it. Large bore pipe straight from turbo to rear of car, then splits into a Y into two rear silencers.
Would love to spend £200 on tyres, but there\'s only about £70 left in the budget!! The tyres on there have plenty of tread but are a questionable brand (NEXEN?). As Pirelli used to say - \'Power is nothing without control\', but should be a laugh at least!!
Can you send some pics of the Monos ? I have a few sets on ebay at the moment and especially the Racing Sparco ones would fit your requirements exactly, nice wide stance and fill the rims nicely buty i need to know soon before someone bids.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=270201287041&ssPageName=STRK:MEWN:IT&ih=017 (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=270201287041&ssPageName=STRK:MEWN:IT&ih=017)
There you go pdtaylor. It\'s the original ebay advert with the MOMOs shown on it. What\'s the ebay number of your wheels mate?
It\'s OK, I think I \'ve found them. Look good to me.
Quote from: grinderdid someone call :D :D :D
i love it when people work to budgets - just like me :D :D
the rot in the car will cause you the most probs - its a pain to fix ( click the link in my sig for the website - and have a look under the rust section )
if you run at .9 bar of boost everything should be fine - and why fit a boost controller if you are on a budget - it seems pointless to me
strip everything out of the car - why make it faster when you can make it lighter :D :D - get all the back seats out
if you can - take off the AC and air pump ( should free up a few HP - say 4-5bhp )
the spec of the car - you should be seeing about 230-250 at the fly - so thats pretty good
we need pics and all updates you make to the car though :D
Stu
As per what Stu said, but take the air pump off AFTER the MOT, as it will help you get through it ;)
Thanks Prof, like your thinking.
Quote from: TeamTotalWankelpdtaylor,
Thanks for the offer of the brakes, top man. The backs seem OK but haven\'t had a real good look at the fronts as yet. The ceramic pads sound just the job though, especially if they\'re cheap!! The car\'s an S5 (\'90) but unfortunately it\'s already been fitted with some 7.5x16 MOMO alloys (225/50 rear 205/45 front) with no spigot rings!! I\'m trying to source some at the moment. I\'d be quite happy to swap these for a std set with good tyres if anyone has any though.
grinder,
Why just make a car lighter, when you can make it faster and lighter?!? ;o) Back seat are out for welding, and staying out.
The boost controller I\'m fitting is the manual (MBC) \'cheap as chips\' variety, not the mega money electronic variety. Is 0.9 bar the max I should aim for then? Can\'t I go for the full 1 bar for this short blast? The chip I\'ve fitted is supposed to give \'safe\' mapping up to 1 bar.
Did they all have AC? I\'ve not even looked, been too busy welding.
Thanks again guys,
Nick
Problem is the intercooler, then the turbo. The stock turbo is past it\'s efficiency limit after 12-13 psi, so although you can get a bit more out of it, not much. The stock intercooler is woefully inadequate past 12psi of boost. I would say to avoid engine carnage keep the boost at 0.9 bar tops, and consider a simple sprayer for the intercooler - every little bit helps. A bit of hozelock irrigation pipe and sprayers fitted up to a salvaged washer bottle should do the trick. With a button in the car for spraying :)
Irrigating the RX7, now there\'s a thing!
If you\'re serious - would you just point them so they spray across the top on the intercooler front to rear? The headlamp washer bottle should do the trick shouldn\'t it?
that would do it as well.
I got the idea of doing that from Brett - who\'s played around with it too, but the Scooby and Evo guys have this sort of setup. Ideally it would be on a boost switch so that it came on when you gave it some welly, but a manually operated one would be just as good for a little bit extra.
I plan to put mine in the rubber grommet that sits on top of the intercooler, and spray onto the intercooler from the 4 corners. The amount your spraying will not be much, and evaporative cooling will see most of it go off as vapour, but the cooling effect will be quite a boost to the intercooler.
Only thing I will say about the water sprays is this - they don\'t make you popular at drag strips.... (Or you could open the bonnet just before the run and freeze the intercooler with a CO2 fire extinguisher...)
If your removing the Air pump and bits like that see if you can acquire a biggish electric fan and do away with the Manual one on the front of the motor (its more to stop the belts slipping to the water pump once you remove the Air pump than any serious power gain but it all helps ;))
Another tip is not to lose the stock air box (if its still there) just drill some big holes in the top, it will flow just as well if not better than any induction kit and it will come with Mazda\'s own cold feed as well.
Also check if its got a steel of Ally bonney on, if its steel try and run it as much as poss with the Bonnet off ;) they weigh allot.
Thanks guys, all tips noted and gratefully received :chat
Does a car need a bonnet to be road legal? I don\'t think so, but it may not be in the spirit of the event to lose major parts of bodywork! I\'ll have to make a few tentative enquiries.
I\'ve already replaced the std airbox with an ebay special induction kit, it was cheaper than replacing the manky std filter! I\'m going to try to retain the std cold air feed and get some more piping in there also. Which will all be fairly academic if I can run without the bonnet :evillaugh
http://www.mazdarotaryclub.com/forums/showthread.php?t=47375
theres a picture on there of my cold air feed, its pretty effective
pdtaylor,
Did you have a look at the Momos mate? Any good for you? If so did you have a swap deal in mind to help the cause?
Cheers,
Nick
whats wrong with the wheels you have ? - just missing spiggot rings and naff tyres
i have some spare wheels but 1 needs a full set of rubber and the other are only 15\'s :(
did you buy some lowering springs ( i have a full set of Pi lowering springs in the garage ) ?
oh yeah - dibbs on the exhaust !! LOL :D :D :D
Decent panel filter is all you need :)
grinder,
Yes I got some brand new SPAX springs of \'rx7kid\' yesterday, he only lives down the road from me. Thanks for the offer though.
There\'s nowt wrong with the wheels I\'ve got, but if someone was to offer a straight swap for a set with better / stickier rubber already on then I\'d have to rip their arm off!! Not fussed what they look like really.
PS 1st dibbs noted :Laugh
brett,
I\'ve already bought and fitted the induction kit (cost me all of £16.99!!) so I\'ll just have to make the best of it, feeding it plenty of cold air.:Thumbs-up
my wheels wont help then
the 15\'s have yoko tyres - but they look like a winter tread pattern on them - and the other 16\'s are bald :(
No probs grinder. I\'m not too bothered about \'competing\' on the existing tyres, it\'ll just add to the excitement!! :2eek
Might have a non-vented FRP bonnet up for sale soon, if you need to use a bonnet for the competition.
Will need racing pins as it doesnt have the underskin with hinges and lock on (but is much lighter \'cause of it!). Has black gelcoat impregnated in the surface so doesnt really need painting.
When you say non-vented, do you mean the big hole in the middle for the intercooler?
If it\'s for sale it\'ll have to be reet cheap as we\'ve pretty much blown the budget! ;)
Quote from: pdtaylor18Looks a good poly bush kit, think i got the more comphrensive one as mine came with everything and for the whole car.
This should be an interesting project, sort of thing i would have done a few years back. Strip the car totally and especially the aircon but keep the power steering if you are doing some handling stuff. Put a new set of plugs in it even if they look alright and certainly go for 9\'s all round. is this a S4 or S5 ? basically 1989 onwards will be S5, just asking as the S5\'s have a better turbo and more BHP (200 standard). Dont put any large wheels on, the standard TII alloys are quite light and the tyres will be dirt cheap.
If you have trouble with the front brakes let me know as i have a few sets of calipers sitting around, i\'m just taking off some really good. almost new disks if you need some. I will hunt around and see if i have any pads, got some ceramic ones that eat disks but perfect for you and what you are doing, probably clean the disks up a treat !! Where are you based ? if i can help you out then i will. I have lots of spares for the TII.
pdtaylor,
Looks like I will be needing some front pads. How much do you want for the ceramic ones you\'ve got mate? I\'ve stripped my calipers and might also need a couple of decent pistons as mine are a bit ropey.
Any help will be much appreciated.
Cheers,
Nick
Hello and Welcome mate. Nice project. Glad to see the boys are all helping you out. I think you have already found that the Rex boys are very helpful.
Good Luck and post as many pics as you can. :3gears-rh
hire a bugati for the day, £1k shud cover it lol
Challenge update-
Managed to have a real good crack at the car this weekend, even though it was my birthday so had to go to the boozer too!! :guinness
Hopefully we\'ve finished all the welding now, just need to seam seal and underseal the lot now. We\'ve tidied up all the existing repairs so they don\'t look like they were done by Stevie Wonder :cool
We went a bit mad on the lightening and removed everything trim wise in the back of the car, it really is bare. The followings also gone- rear bumper bar, towing brackets, rear wiper, washer bottle, electric aerial etc etc. The result is 2 pretty heavy cardboard boxes full of surplus sh1te, and a car sat with its rear up like a dragster. The front end is yet to be stripped / lightened.
The rear ride height\'s now been sorted. I removed a rear strut to fit the Spax spring only to find the rubber/metal/rubber sandwich top mount had dissolved :2eek The shock wasn\'t located to anything at the top!! So in true \'challenge\' style the old mount went in the bin and we made a new one out of the old top plate. Getting rid of the rubber sandwich also lowered the car about another inch to level things out nicely. A front strut was tackled next (top mount OK :yes ) and fitted with a Spax spring. I wanted to add some negative camber to reduce potential understeer on the slalom course so slotted the top mounting hole where the strut meets the hub. This seemed to work a treat but I\'m yet to measure how much I\'ve managed to get, but will be happy with 1.5 - 2deg.
After the back brakes were all OK we were hoping the fronts would be the same. Oh no, the first one had 2 out of the 4 pistons siezed solid. We managed to pump them out eventually and got the whole lot cleaned and rubber greased up, to hopefully hold fluid! We\'re yet to tackle the other side but it looks like we\'ll be needing some pads at least (pdtaylor?).
So thing are coming along quite nicely and I reckon we could be back on the road if we get another good weekend in. The car is starting to really look the part now, low and mean!!
The \'challenge\' car is just about ready and is back on the road, MOT\'d and everything:yes.
I\'m pleased to report that she bl00dy RIPS!! :eek: Well impressive performance.
My first test drive with its cheap and cheerful boost gauge fitted was showing a peak of about 12psi, but this would decrease as the revs rose on full throttle. I then fitted the MBC and got some cold air feeds into the induction kit. With the MBC slackened right off the boost still peaked at 12/13psi but seemed to hold this right upto 7Krpm. I gave the MBC a couple of turns in while I was out in it today (just couldn\'t help myself). The boost now peaks at 17/18psi:2eek, but again drops off to about 10psi with the revs. I\'m hoping to back it off and find a sweet spot around 14/15psi, and see if it holds boost at that level.
Since my last update the car\'s lost even more weight with the carpet coming out. The steel front bumper\'s gone, just leaving the skin c/w stick on plate (every little helps).The air pump will have to stay in place as there\'s nothing in the budget for a twin alternator pulley etc
Here\'s the finished spec-
Engine- 3" de-cat exhaust, induction kit with cold air feed, Stage 1 chip (1bar mapping),MBC.
Suspension- poly bushes fitted, spax springs, neg camber on front.
Brakes- new std front pads
Body- all interior removed (except drivers seat), steel bumpers gone, washer bottle leccy aerial etc etc binned.
Now I\'ve felt the way that this RX pulls I can\'t wait for the event :Giggle
Cheers,
Nick
Sounds like your about done then. So if the car is sorted now I guess the next thing is how goods your driving?
Whats happens to the car once the event is finished?
sounds like you are having a whale of a time matey :D
Quote from: adereed;496686Sounds like your about done then. So if the car is sorted now I guess the next thing is how goods your driving?
Whats happens to the car once the event is finished?
Hopefully the driving shouldn\'t be a problem, but it is very different to what I\'ve been used to. I\'ve got a bit of previous, competing in the Slick50 Road Saloon Championship for a number of seasons in the early 90\'s. That was in FWD VW\'s \'only\' putting out about 160bhp, so no real comparison.
I\'m not really sure what to do with it after the event. It\'d make a great track day car, but I don\'t know if I\'ll have the time to get the use out of it as my other hobby (Lancia Montecarlo) needs driving too. The car stands me at £1K, but I\'ve put an awful lot of labour into it. I may ebay it afterwards to try and recoup my labour costs, if i don\'t get a decent offer beforehand ;)
PS. How do you download images on here? As I don\'t have pics hosted on a URL.
Im not sure you can post pic\'s if your not a paid up member. you can email them to me if you like and I will post them up for you. tiddlesrx7@bigstring.com
I was thinking if you were gonna break the car afterwards I would make you an offer on the chipped ecu
Cheers mate, just sent you a pic to post. Not great quality.
I don\'t think I\'ll be breaking it unless something goes drastically wrong!! The ECU chip was only £25 off ebay and seems to work a treat. I soldered it in myself (used to be my job) but the place would do your own ECU for £50 if you send it to them.
Here\'s the pic of the car. I was looking at the chips on Ebay. I wasn\'t sure about them but if you have one and it runs well then I may just order one. I have a spare ecu so I can have a go at it myself.
The chip I got was ebay number 170184726338. The car seems to run fine with it in and the boost limit / fuel cut I was hitting before has gone. I\'m yet to find the rev limiter:2eek. The hot tickover did need adjusting. If I remember right I had to wind in the bypass screw near the filter before the idle screw near the inlet came into \'range\'. It passed its MOT last week with 2.5CO and 800HC, happy with that:Giggle. The hardest part of the chip swap is getting the old one out as I no longer have access to a Pace solder station. So you might want to make sure you can get it out of your spare ECU OK before ordering.
Does your car hit the boost limit then? Or do you have an FCD fitted? Mine was cutting all the time just with its decat exhaust and induction kit.
Do you know if the chips control timing at all ?
1 Bar is a lot to throw at the FC - can\'t remember if you changed the intercooler or not - if you didn\'t your intake temps are going to be quite high ! :2eek
No im running a FCD, it was on the car when I got it. But with the mods I have I should be running a FD fuel pump and a chip or remapped ecu. I haven\'t hit the rev limiter either and its been well above 7k in the past.
Prof,
I\'ve no idea if it\'s controlling the timing or not. It\'s on the std intercooler still as the budget\'s blown!! I did clean it out so it should be working as well as it can at least. I\'ve backed it off to about 12/13 psi now, but it seemed to be boosting at that without the MBC fitted :confused:. Either way, the boost seems to tail off to 8/10 psi when it is pulling over 5krpm. Is this normal? Or might I have a leak or turbo problem?
Cheers,
Nick
When you fitted the MBC, did you disconnect the stock boost solenoid - it tends not to do much when you\'ve chipped the ECU, and if it\'s connected it will probably be the cause of the boost drop off.
There\'s a good article about boost and boost creep on the 1300cc.com site - http://www.1300cc.com/howto/how2/creep.htm - will probably help explain it better than I can. :)
Cheers Prof,
I\'m just getting Gateway Timeout on that link, I\'ll try again later. Can you please confirm which is the Boost Solenoid?
Cheers,
Nick
Quote from: TeamTotalWankel;497249Cheers Prof,
I\'m just getting Gateway Timeout on that link, I\'ll try again later. Can you please confirm which is the Boost Solenoid?
Cheers,
Nick
Mine has a blue connector plug and sits on the oil filler neck - if you follow the pipe back that \'Tees\' off the small pipe on the turbo compressor housing, the other end of that is fed from the stock Boost Solenoid. It\'s designed to bleed some air away from the wastegate, preventing it from opening until later, but the solenoid can be erratic and also can leak. If you just pinch off that pipe near the turbo, you\'d be running on spring boost only on a stock car, but with intake and exhaust mods that would have risen to the 8psi that the solenoid gives you in any case. More than likely it\'s leaking boost away.
Thanks again Prof. I think I\'ve located it on a diagram, the duty solenoid valve (turbo boost pressure control) sound about right? So if I pull the wires and the boost still drops off then pull the pipe and blank it off?
I plumbed in the MBC below the tee, next to the actuator. I guess if I\'d done it above then I wouldn\'t have this issue?
Cheers,
Nick