Marks RX7 - lets break a rotary.

[Adey]

are they self supporting or do they have a bracket?

 

[Mark Davis]

are they self supporting or do they have a bracket?

They have a bracket

 

[Brigsy]

Aem coils no good or just getting rid of ht lead?

 

[Mark Davis]

Aem coils no good or just getting rid of ht lead?

Just eliminating the leads mate. Had some strange burn marks/hot spots on the two of the coil terminals and leads.

 

[Brigsy]

Fair play. Agreed ht leads are always a weak spot, no matter how much they cost they still fuck up.

 

[Mark Davis]

Fair play. Agreed ht leads are always a weak spot, no matter how much they cost they still fuck up.

As with any kit like the AEM the leads had to be made custom and they were never quite good enough. Think they were Magnagor but never quite clipped on well enough hence some interesting burn/heats marks on both rear rotor coils (this is the failed rotor each time, not saying this is the sole cause though). I managed to source some MSD ones but they were not the right length so we’re dodgy too.

From what I’ve read R35 coils are proven on cars making north of 1500hp so massively overkill but good for future proofing I guess.

I’m going to run the car at 1bar moving forward, will make around 500, probably a little less but hopefully live for more than a week. Then over the winter go down the flex fuel route, I don’t mind keeping a 200l drum of E85 at home

 

[Steve Swan]

The more power you make the harder the ignition system has to work. High compression and rich mixtures (like when you floor it at mid RPM) will always be where weakness will show up,as they effectively Quench the spark, that said I was talking about conventional piston engines. How do rotaries compare?? what are the combustion chamber pressures? I guess they are lower than traditional motors. They rev much higher which is where the big numbers come form and this in turn will work the ignition system harder. Having as little HT system as possible can only be a good thing as it minimises leakage, also I guess multiple coils have more recovery time than a single, then there is the failed coil if you still have the rest you can limp home (provided it's not too far) The only thing that bothers me, is that today a lot of clever engineering is used, in conjunction with much penny pinching to arrive at solutions which are technically great, but made out of absolute trash as they have a finite life. On another line of thought, I assume Mazda exhausted the rotary concept from an emissions point of view. This design was never going to be a clean burning option, but with turbocharging, would surely have reduced emissions. Look at all Eco. motors today all are forced induction as they would not work without it. Funny how the lessons learnt before the First world war were avoided by manufacturers until quite recently. Harry Ricardo said back about 1926 that poppet valves would restrict engines to 1500HP maximum. He was right from his point of view at the time and the 4 stroke conventional engine has been taken to it's logical limit. I enjoy this thread because there is a better solution out there which is not conventional, but is not being given a fair chance, because the people running car companies today are most likely not the kind of people the Founders would have hired . @Mark Davis keep developing this, I love reading about it's ups and downs and most important the lessons learnt along the way. Hopefully there will be a period of ups and this will pacify the finance director.............

 

[Mark Davis]

150 miles completed with no issues so far. Car is tuned to 1bar with a rev limit of 7300, makes all the right noises and is pretty quick, likely around 450hp. Only downside is it needs the extra 1200rpm or so as peak power is pretty much on limiter - I’ll be patient this time though and leave it be until I’ve got a good amount of miles on.



I drove over to Bicester yesterday for a 7s day event, 70 RX7s all under one roof. Here’s a few of my favourites.

 

[Mark Davis]

The HSDs are 12 years old and I don’t like them on any of their settings so I’ve upgraded to Ohlins.

 

[Mark Davis]

Project flex fuel is a go.

 

[Brigsy]

Keep us updated on how it goes. Id like to do similar on the Trophy in the future. With the current prices of fuel on the pump, the price of drums of vp racing e85 does not look too horrendous for occasional use

 

[Mark Davis]

Keep us updated on how it goes. Id like to do similar on the Trophy in the future. With the current prices of fuel on the pump, the price of drums of vp racing e85 does not look too horrendous for occasional use

This is partly my thinking too.

I keep a 200litre drum at home, when I really want to go out and kick its head in I whack in some e85, go full boost and love life.

Then when I burn through that (likely very quickly) I just put in pump fuel and the ecu adjusts accordingly. I’m hoping it’s the solution to keeping det away and my engine alive.

 

[Mark Davis]

Out with the crusty 12yr old HSDs, in with the Ohlins. I’ve left them on standard settings just well i get a few miles on them before adjusting too much and they are already way better than the HSD, my old man back pain can notice the difference in the dampening.

 

[Mark Davis]

I bought some new rear led style lights from Japan. I think it modernises the look quite nicely. Just the 6 month wait for these.



They do all sorts of funky shit with the indicators but I’ll stick to normal blinkers or flowing like below.



In other news I’m having a fuelling issue, I believe it to be the pump so a new one arrived today, just waiting on OEM fuel filter too so I can swap them out at the same time.

My ECU did a great job at saving yet another engine by hitting the differential fuel cut safety as it drops below 33psi and isn’t raising with boost, on a standard ECU id definitely be on yet another engine.

I’ve lined up the works to be done for my E85 set up in October. Radium in tank set up with swirl pot, dual walbro 450s plus an additional lift pump. Coupled with AN8 feed and AN6 return it should be pretty spot on. I have the flex fuel sensor and loom already, looking forward to some E85 goodness early next year.

 

[andybond]

Those lights are crackers! So much want!

Great news on the ECU. Seems like a sound investment already!

 

[Steve Swan]

I think that when you are nearly splitting the atom inside the combustion chamber, Proper engine management is money well spent. Your eyes, ears, nose and right foot is not fast enough to save the day.. Looking forward to hearing about the new system. I don't claim to really understand it, but it will be a great read..

 

[DaveL485]

I think that when you are nearly splitting the atom inside the combustion chamber, Proper engine management is money well spent. Your eyes, ears, nose and right foot is not fast enough to save the day.. Looking forward to hearing about the new system. I don't claim to really understand it, but it will be a great read..

I think the "normal" human reaction time from <thing happens> to <physical reaction> is about 0.4 seconds at the lower end - thats over 50 engine revolutions at 8000rpm - we're just not fast enough!

 

[Mark Davis]

I’ve made a somewhat frivolous yet exciting purchase.

95% complete (barring gaskets/seals/bearing) semi peripheral port 13B for my next engine when the current one inevitably explodes.

These set ups make some serious power and move a shit load of air. With the right turbo this is 700whp territory. Also means less boost required per HP making it more efficient in general.

Spec is as follows;

13b rew
Semi pp
All stock ports 100% untouched
Resurfaced housings
CNC’d for 1/2” through studs
External oil feed
Copper sleeves
Balanced rotating assembly with auto rear counterweight
Lightened, race clearanced, and face clearanced rotors
Solid dowel pins
5x 1/2” through studs
10mm studs
ARP nuts
2x SCR fuel rails
SCR upper and lower 4 barrel intake manifolds and gaskets
SCR 90mm throttle body with tps
Power Seals 2mm methanol apex seals

Some pics;

 

[andybond]

I do believe I mentioned 13BB PP a bit ago. Get your working lump out stat and sell it! This is going to brap for days

 

[Mark Davis]

I do believe I mentioned 13BB PP a bit ago. Get your working lump out stat and sell it! This is going to brap for days

you planted the seed