My Rx8 build

Thread in 'Project Cars and Builds Threads' started by F51, Jul 1, 2015.

  1. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    So i just bought a non running rx8, Im sure most of you are already thinking this was a crazy stupid decision but I really wanted to take one apart and rebuild it. The car its self is a 2004 231 model and has more service history than any car i have ever bought, it even has stamps right up until 72k all with mazda specialists. Unfortunately In an Rx8 that counts for very little it seems. I actually paid next to fuck all for it so thankfully if it all becomes too much scrapping the car will recover me my cash!

    I was told it had low compression on the first rotor, after speaking to a few rotary specialists they have told me that numbers from normal compression testers are pretty pointless and that rotary specific testers are needed to record compression. they also stated that alot of the time garages/rotary forums scare monger and some times the cause may be as simple as a blocked cat or a ruined coil pack. It turns out that amongst the extensive history there is no sign of a new cat or it ever having the coil packs and leads changed! it seems these usually last 25k ish so these coils should have been coming up to their 3rd change! It is likely that they have been changed before under warranty and maybe the paper work not kept.

    so first things first is to get the car home and determine exactly what is wrong with it, do i get to pull it out and take it apart? or is it just a simple fix that has been over looked.

    Second thing, once the problem is found is to get it back working.

    Third thing will be to strip the car of everything that isnt needed and either sell it or use it to build some kind of fort. The car will never be used on the road as i have no intentions of using it daily and im too poor to run it day to day.

    last thing will be to make any modifications needed to be a suitable drift/track day car. so Bucket seat, Harness, lock modifications, some upgrades to the brakes and to the suspension. eventually i may progress to increasing power but i have way more reading up to do before i think about that. anyway here is the car still say outside its previous owners house until i find a nice cheap a frame to tow it a few miles back home.

    [​IMG]
     
  2. LOKISY

    LOKISY Member

    Joined:
    Sep 16, 2007
    Posts:
    935
    Likes Received:
    0
    Hope it's a simple fix! Good luck.
     
  3. PurcyP

    PurcyP Member

    Joined:
    Feb 19, 2014
    Posts:
    184
    Likes Received:
    0
    If it had low compression on the first rotor then surely there would be a print out for you to hand for a compression test?

    generally a crapped out coilpack and or cat will report a misfire
     
  4. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    Well there is something about a compression test being done but its from a normal garage, after talking to a few specialists they say that you can only get readings from a rotary specific tester and the testers are rather expensive. It makes me think the original compression test is pretty much useless. the rx8owners.co.uk guys have said to try seafoam as if it has lost compression it may be down to carbon/crap stopping the seals working as they should do.

    Do any of you who live around the hampshire area have an A Frame i could rent to tow it? I have one but my brother used it and he is away for a few weeks with work.
     
  5. PurcyP

    PurcyP Member

    Joined:
    Feb 19, 2014
    Posts:
    184
    Likes Received:
    0
    You can..to a sense use a normal compression tester if you know what to look for in the pulses

    compression tests at a rotary garage usually cost around £50-£70


    Go with the seafoam but to be honest id be looking at a rebuild, the carbon build up etc even if you clean it out the damage is probably done as it causes the seals to get chipped and break, score the housing etc.


    No on the A frame im afraid
     
  6. Tommy59

    Tommy59 Active Member

    Joined:
    Jan 4, 2015
    Posts:
    248
    Likes Received:
    40
    My first port of call would be to remove the coilpacks, leads and plugs and inspect them. Due to the position of the plugs, the leads and plug tips sometimes corrode so this might be worth checking. Along with this, over time the insulation breaks down in the coilpacks and they begin to earth out the top of the coilpack causing little white heat spots on the coilpack and a weaker spark. You may not have any of these issues but it's well worth a check.
     
  7. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    with the coil packs, is it worth getting uprated? do they last longer or is it just a waste and better to get mazda parts.
     
  8. PurcyP

    PurcyP Member

    Joined:
    Feb 19, 2014
    Posts:
    184
    Likes Received:
    0
    I never ever had issues with latest generation mazda coils.

    they have gone under various updates, if you start putting the power down and look at turbos etc then going to LS coils isnt a bad idea.

    in terms of the now and checking if its duff coils that somehow caused low compression then i wouldnt spend money, see if you can borrow a set including leads and plugs if need be.

    however if it genuinely is low compression on rotor 1 then all the coils in the world wont cure it, if the buyer said its low compression but in fact a misfire on rotor 1 then entirely different and cheap story.

    but judging by what you said, id be saving pennies for a rebuild.
    excess carbon build up will chip away the apex seals and score the nitrate liner or whatver it is they use, of the housings.

    Also a worth while thing to look into is either premixing or fitting a SOHN adaptor, rotaries like two stroke like a fat kid loves mcdonalds.
     
  9. -sideslide-

    -sideslide- "ent it"

    Joined:
    May 21, 2010
    Posts:
    1,936
    Likes Received:
    0
    bin the renesis pile of junk bud it really has no power even new or with a rebuild, They also aren't a massive fan of been turbo'd

    If your going to start to throw a few grand at a new/rebuilt engines and want a fairly start forwards(minus the electrics mind) then buy a 13b turbo motor(the rx7 FD one) it goes it quite easy means its pretty much the same thing. Getting all the dash to work is a bit harder but if I can do it any one can tbh,
     
  10. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    if i was to go through the effort of an engine switch i would probably put the 350 v8 i have sat at my dads house in there, run it on holley carbs and sack off as much electrical stuff as i could lol any engine switch would bring its own set of issues even if it was to a 13b, if it didn't everyone would have been doing it already.

    I haven't even recovered it to my house yet lol, I am busy until next tuesday testing all of Southampton's players in the lab.
     
    #10 F51, Jul 3, 2015
    Last edited: Jul 11, 2015
  11. -sideslide-

    -sideslide- "ent it"

    Joined:
    May 21, 2010
    Posts:
    1,936
    Likes Received:
    0
    V8s are a pain in rx8 as the length means passing around moving the steering rack it's also makes access almost impossible the best conversions are the v6 or rotary.

    I put a Sr in mine but i would go v6 next time.
     
  12. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    wouldn't the 2.3 out of the mps be a better fit? the mx5 and rx8 front subframes look the same, almost identical so i assume with some work other mazda engines would fit.
     
  13. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    So today I Finally got the Rx8 home, I managed to get my brothers missus to drop my A Frame Off and decided to risk towing it with my little focus. Safe to say I will be looking for a new tow car very very soon! It struggled to get to 30 and every tiny bump dragged me all over the place! Anyway i was pretty happy to finally get it home [​IMG][​IMG]

    It has really started to Grow on me, I absolutely love the shape and overall look of the car, so i set about trying to get it to run or at least sound as if there was some life in it.

    The battery was totally dead so I took it off to put on charge and used one of the many spares i have ready charged. I gave it a quick turn over but it sounded pretty odd!

    I went to check the leads/coils ect were ok to discover all the leads were detached, so I jacked the car up to find the second row of plugs, being my first time working on a rotary I had no idea how it was all laid out. When i looked closer It became obvious as to why i couldn't find the second row of plugs, The bastard of a previous owner had removed them! So I now have to go and buy a new set.

    [​IMG]
    Looking at the car now, If the engine doesn't fire with new plugs in I will pull the engine out and start looking for a 13B out of an rx7, I realise this swap does present its own problems too but I think i would like to stay with the rotary.
     
  14. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    A few things I have noticed:

    The shocks although not leaking don't look as though they have much life in them
    A few of the suspension bushes look slightly perished
    The brakes have a bit of rust on them and the pads are low
    The ride height is way too high for the car! Im not really a fan of things being unpractically low but it looks to need 30-50mm taking off the height all round
    The wheels are pretty ugly and heavy so will need changing in the future
     
  15. PurcyP

    PurcyP Member

    Joined:
    Feb 19, 2014
    Posts:
    184
    Likes Received:
    0
    Ironically the rx8 wheels are some of the lightest oem wheels in class.

    Regarding ride height i stuck koni sport kit on and lowered lovely amount and the ride was spot on, was like it was never lowered. However these are limited in adjustment, ride height is fixed damping can be changed fronts via a key and rears off vehicle.
    Cant remember the number it lowered by but the arch gaps were gone, looked good whilst being sensible.

    Also why on earth did he remove the plugs n not tell you, how odd.
     
  16. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    Im not so concerned with sensible, it will only ever be used on tracks so I am looking at different types of coilovers, I wont bother getting bits like that until it is all back running though.

    I know, he also took out the standard head unit after I had bought it! It has the heater controls on it as a complete unit! I had locked the car but the passenger door was unlocked when I went to collect it. He has moved out now too and wont answer his phone, He lives somewhere close by still so if I see him I may have to give him a bit of my short temper.

    Luckily my dad broke one up a few year ago and one of the parts he has left is the headunit/heater controls. Unfortunately the engine was the first thing to go off that one but he has a spare 6 speed gearbox/prop/ diff and complete rear subframe just incase I damage mine on track and a few panels in black incase I stick it in to a barrier.

    With the 13b out of the FD Rx7, Does it mount to the RX8 gearbox? I know the bulkhead may need modification because the inlet needs a few inches extra and that the turbos make it a tight fit down the sides.
     
  17. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    [​IMG]

    Just got the coil packs out and they are showing the white marking underneath suggesting they are pretty much dead/dying That might account for the hot start followed by not starting problem the previous owner had.

    Im going to try source some second hand ones with plugs off the rx8 owners club just to test and see if that is the only issue.

    I have been advised that if it has these white spots to check the cat hasnt crumbled and blocked the exhaust so that will be my next task Hopefully it turns out to be a nice quick fix!
     
  18. PurcyP

    PurcyP Member

    Joined:
    Feb 19, 2014
    Posts:
    184
    Likes Received:
    0
    in the case of the suspension then, go for whatever tickles the pickle, plenty of kits to choose from which is good.

    Cheeky fuck taking stuff out of the car under the presumption of its included in the sale, getting the head unit out is no 5 minute job either what a fucktrumpet id be going mental.

    Good thing you have spares to hand i guess.

    In regards to the 13b i cant help you on that one, but it would be worth if you go down that route to be a single turbo rather than the massively complicated sequential turbos, all those vacuum lines etc makes my head ache.
    Places like heyward rotary can point you in the right direction if you go down that road.

    In regards to coils, the white spots are a bit of a misconception, and cause of so many arguments lol, the engine bay gets unholy hot, its that heat makes the insulation go a bit white, only way to tell if the coils have gone is if the car misfires, you can test the coils by looking at the ignitior resistance and timing lights and all sorts of crap, but generally youll find the car will run and the check engine light will flash and record a misfire. That being said i am not ruling out the coils are the problem as you said in the original post they havnt been changed in forever. A lot of people stick by the white spot rule as its coincidental that the coils fail and the white spots are there. hence the arguing starts.

    So with that hopefully it is a cheap fix, if you wish to stick with the renny that is
     
  19. F51

    F51 Member

    Joined:
    Nov 7, 2014
    Posts:
    228
    Likes Received:
    0
    Well i have just bought a set of coils and plugs off a friend, they have only done a few thousand miles before he stuffed it in to a tree backwards lol

    yeah i know! It just so happens his son lives somewhere near me so i might have to go bang n his door.
     
  20. Ianisawankel

    Ianisawankel New Member

    Joined:
    Apr 4, 2015
    Posts:
    12
    Likes Received:
    0
    looking forward to see what you decide to do with yours mate
     

Share This Page