Project Cosmo 20B rebuild thread

[frank20bcosmo]

well guys after over a year the time has come the piggybank has been raided and the Cosmo has gone in today for the engine re-build
It has gone in to WGT Devlopments in Middlewich Cheshire UK a rotary specialist here in the UK, look them up on the WEB, Pip Gardner is the genius builder who will be getting up close and personal with my baby again, I will be going along to see him and have a heart to heart when he has it stripped and we can discuss which way we are going with it this time to achieve what I am after, I am thinking along these lines

Street port (already done last time)
keep the sequential twins
stand alone ECU (after run in period) Microtech preferred
Bigger intercooler (to discuss with Pip)
looking for 450 - 500bhp at the motor
may need secondary upgraded injectors (to discuss with Pip)
Full de-catted exhaust (already done 2.5 inch twin exit system)
No pre-cat (already smashed out of down pipe)
Boost controller (already fitted which caused engine to over boost so wont be used until ECU upgraded)

I will keep you updated on what Pip reccomends to achieve this

After engine Mods other work to be carried out

19" alloys
adjustable suspension (BC Coilovers)
complete the fitting of the remainder of the Dealer installed Mazdaspeed kit and paint to colour code the car (includes illuminated Cosmo logo on side skirts)
polish engine parts such as intake and hard pipes (to be done when engine stripped)

I will keep you posted with pics as the work continues with updates on all developments good and bad (not many of the latter please) (drinks)

Regards Frank

 

[rodneooo]

Good to hear its getting some work done! Fun times

Im not 100% on the flow capabilities of the 20b twins, but on my car (13btt) once ported the twins definatly choke the engine above 5500rpm. I was also expecting to make more power after the rebuild, but it ended up making much less than b4 the rebuild and porting. more poke in the low and mid range but virtually nothing up top due to severe flow restistion.

i think you may struggle to reach your power goals with the factory twins. also u wont enjoy the power it does make if chokes in the top end. i know it kills my life knowing what is capable of without the twins.
U will also want to limit boost to 12psi or they wont last too long.

Im only keeping my twins for the mean time as the car being daily driven.
Just to give u an indication on the difference betweens twins and large single.

Current setup 190hp @ wheels - 12psi
exact same setup, but a tired std motor 210hp - 12psi ( made 20hp more with smaller ports and low compression.... go figure lol)
same setup with t04z 330hp - 14psi (bucket loads of mid-top end, very fun indeed, mush more rev happy) this isnt even in the turbos sweet spot yet...

In short, ditch those turbos !!!!!!!!!! or lower your power goals

u will definatelty want larger fuel pump, a decent sized intank is an easy upgrade. secondary injectors will be needed depending on boost levels. about 14psi would be the absolute limit on factory injectors.

Do u have your heart set on a microtech?
there is a fair bit of work to piggyback them properly and retain all factory functions esp if keeping the auto box.
Haltech offered plug n play looms for e11. If your can get your hands on one id grab it right away.
if u were to weigh up the pros and cons of each setup and installation, the haltech will win hands down. plug n play loom, full boost control, uses all factory sensors & coils & all round a much better ecu..
With the microtech u will have to change alot sensors & coils (i think) and totally butcher your loom with a fair bit of rewiring.
Soemthing to think about... But at the end of the day its a matter of what your tuner is familar with.

Just my 2c for a fellow cosmo owner.
All the best with the build, be sure to keep us posted.

 

[frank20bcosmo]

Hi Rodneoo
I am open to what the builder reccomends I know he has fitted Motec recently in a 20B but that was in an RX7 (manual) so it could be an issue with the ato box but when I get to sit down and talk with him I am sure we will come up with a solution, I have not had the phone call yet to tell me what he has found when he has pulled it apart, could be he has not got that far yet but I am in no rush, its not like its the middle of summer here, I am hoping it has not damaged the housings which will save some cash to spend on other things,, but I am not banking on it as when you do it is usually ends up worse than you thought (deadhorse

 

[mazda speeder]

Hey Frank, taken the plunge eh' (drinks)

i will be following this thread keep the updates rolling in, any pics from our builders workshop would be great.

anyway best of luck

 

[frank20bcosmo]

A quick update, just spoke to Pip at WGT
Engine is out and stripped, as suspected broken tip on rotor thankfully the rotor is not damaged, however housing is damaged and it is the rear housing, luckily Pip has located a 2nd hand housing in Washington and it is being shipped over(usa) well I am presuming it is that Washington and not the one in Tyne and Wear (headshake no other damage (breakn) Thank God

Now the bad news, looks like the Motech or Haltech are both out the window due to the automatic box as Pip informed me the stand alones do not like communicating with the auto box, he is thinking a piggyback on the original ECU maybe the best option, he is going to give it some thought which way and system would work best,, Any ideas guys?

I am going over to see him next week and pick the hard pipes and inlet manifold so I can get them polished, I will discuss it further with him then, I will endavour to get some photos of his workshop (as requested Mazda Speeder) and what he is working on while I am there, I have a few shots of the Cosmo being trailered away on her way off to WGT to post up this weekend all being well.
updates to follow, any reccomendations on which piggyback will work best let me know,, thanks

 

[Berty]

I am piggybacking a Microtech onto the Cosmo ECU at the moment. I'll let you know once I have it all figured out.

 

[Herblenny]

If your goal is 450-500bph (350-425 whp), It could be reached through the stock turbos but modern single will achieve this with an ease. Since you are rebuilding the engine, I would ask your builder to change out the restrictive exhaust sleeve. The intake ports on the 20Bs are larger enough to handle well over 600+ whp and usually gain might not be much especially if you are not reaching the limit of the engine. Its usually the exhaust sleeves that restricts the flow (how mazda control the power).

Also, make sure your engine builder is actually getting the JC rear iron... some builders I know would just port match and use different irons, but issue is that the turn in inside the iron is different from 20B vs other engines. This also isn't a big deal but should consider as rear rotor is usually the one goes out on many rotaries.

And finally ECU... Motec is high dollar unit and consider to be the best on the market. Most of these standalones can be ran parallel with stock ECU.. meaning stand alone will run all the engine/power related and stock ecu controlling transmission and such (I guess you could call it piggyback). Problem is that most builders/tuners might not know how to wire it up. At this point, you might want to consult an expert regarding to this as they might need to go through your system and see which wires are which... could be very time consuming for some builders and might not want to take on that task or since not familiar with your car they might not want to spend the time (in this case, very limit wiring diagrams for the cosmo). I would be questioning this shop if he/she said Haltech or Motec will not work, and said you need to go piggyback (as some thinks piggyback ECU is HKS F-con that only controls Fuel/inj).

One thing I would also like to mention is your purpose of building up your cosmo.. My experience is that knowing the goal will help you save time and money. If you goal is daily driving, extra 75-100HP might give you a slight satisfaction, but not sure it is worth 10+K extra money you might spend (Turbo, turbo manifold, ecu, etc. etc). If your goal is track, I would just put the cosmo back to stock and maybe pick up an FD and build it. JC isn't really a track car nor drag car. But if you are building a show car, there is no rule and build whatever you wish, since its a show car where you are building something to just show off. Sorry, this is just my experience and trying to help you save some money and time as I myself have gone through this and seen many people who build purposeless car that waste money and time and later just ditching it and picking up something else.. as they tried to build some 'do it all' car only not meeting their imaginary goal.

 

[frank20bcosmo]

Hi Herblenny, thanks for all the info and knowledge
I can confirm it is a 20b rear housing that he has sourced.
I am not after a track car but as you say a driveable street car with a good 100+bhp over stock, the reason for the ECU change is so the motor does not go bang again, current set up has a free flowing exhaust a good air intake a street port and a boost controller and after the run in period it lasted 300 miles,, when under boost it hit fuel cut and took the tip, I want to be able to set up the motor so that when on boost it is fed properly with the right fuel/air mixture and have the potential 400+ bhp on hand when required.
the only 2 things it is lacking (apart from the exhaust sleeves which I am not sure would of been done last time, but will check) are a bigger intercooler and some sort of computer to control and feed the fuel / air mixture to stop this happening again.
The Greedy e-manage ulitmate seems to be the best one judging by what I have read so far as you can eliminate the fuel cut, speed restrictor, and incease the boost on the stock turbos while not interferring with the electronic gearbox.
what is your thoughts on that system?
what have you done to your Cosmo performance wise or are you leaving it well alone?

Regards
Frank

 

[mazda speeder]

Are you getting the e-manage tuned on a rolling road? i wcould recommend some london dynos?

 

[RenesisKing]

I want one so badly, but I can't have one in the US for few more years due to restrictions. I will have one eventually.

 

[frank20bcosmo]

Are you getting the e-manage tuned on a rolling road? i wcould recommend some london dynos?

I am going over to Pip's all being well on Wednesday not sure which system he will reccomend as the best to use, Pip has got his own rolling Road so can be all done in house, this will not be until the engine has been run in so probably be June or July next year, then again after my chat with him we maybe going a completely different route, MANUAL,, SINGLE TURBO,, but have to cost it all up first, and sweet talk the wife (angel)

 

[frank20bcosmo]

I want one so badly, but I can't have one in the US for few more years due to restrictions. I will have one eventually.

what are the restrictions in the USA? is it age of vehicle?

 

[RenesisKing]

It needs to be about 25yrs of age to be driven on the roads legally. I'll try to find the link. http://www.nhtsa.gov/cars/rules/import/

 

[frank20bcosmo]

It needs to be about 25yrs of age to be driven on the roads legally. I'll try to find the link. http://www.nhtsa.gov/cars/rules/import/

The only problem with that is by the time another 5 years goes bythey will be that rare (especially the 20b) the prices will be through the roof
go on goo.net and see some of the prices now, they have gone up 50% in the last 4 years and with the exchange rate to the yen how it is at the moment it is not cost effective to buy them from Japan at the moment, good news for those that own them now though(drinks)

 

[RenesisKing]

I think I just might bite the bullet and get one next year and just do the work that it will undoubtedly need and just store it until I can register it and drive it.

 

[Berty]

Do not buy the Emanage Ultimate for the 20B.

Greddy never sorted out the AFM issue that I emailed them about, nor did they every address the incorrect wiring diagram issue. You are welcome to have my ECU setup file if you choose to go down this route, but I would not recommend it given that other ECUs are so cheap now.

 

[frank20bcosmo]

Hi Berty,

I have an update coming soon and some pictures to upload, however funny enough my builder said a similar thing and suggested not to go that route either for the same reason. what system are you going with now berty? and have you gone the manual gearbox route?

I will update the thread in a few days and you will see which way I have decided to go(2thumbs)

 

[RenesisKing]

If you are going for a ECU I suggest Microtech and use the LT-12. I have the LT-10 I still haven't installed it on my car yet but on RX-8club people have had great luck with it. Its reliable and fairly easy to use. If you have some issues or any questions give Dave a call at KDR Performance. His shop was bought out by an investor and its called something else but the number is the same I think. Do you ever go to rotarycarclub.com?

 

[Berty]

Hi Berty,

I have an update coming soon and some pictures to upload, however funny enough my builder said a similar thing and suggested not to go that route either for the same reason. what system are you going with now berty? and have you gone the manual gearbox route?

I will update the thread in a few days and you will see which way I have decided to go(2thumbs)

I have gone down the Microtech route also for two reasons...

1. Its about the cheapest standalone that will work with the 20B
2. It works and then has been proven many times
3. There is a large support base

IF I had more cash and more time I would have no issues with sinking the cash into the Haltech PS2000. It is a very good ECU and much more capable than the Microtech, however it is slightly harder to get the car running initially.

I am still running the auto, however I have most of the gear required for the manual conversion. The only reason why I haven't put the box in is because I want to be able to drive my car asap! It has been off the road for long enough.

 

[Herblenny]

what is your thoughts on that system?
what have you done to your Cosmo performance wise or are you leaving it well alone?

Regards
Frank

Hey Frank, I agree with Berty.. Do not use Emanage.. I would go with Microtech, Haltech, etc. I think there are far more Microtech support as Berty said and also you need to see if what kind of support you might have locally. Getting a fancy ECU that you can't get local support might yield headaches at the end... Unless you want to learn and such all on yourself.

I haven't done anything to the Cosmo since the exhaust. I'm planning to keep it how it is and just drive it once in awhile. However, I am now involved in doing a 20B swap into my FD. I started a build thread on here..

http://www.mazdas247.com/forum/show...RX-7-quot-by-Herblenny&p=5833838&goto=newpost

I'll be going with Haltech PS2000 on the new car.