magical sequential twins?
 

Anyone ever heard of "THE DOCTOR" on here talking about his "Bathurst SP 650ps Twins"? He said these sequential turbos had larger turbine wheels (51mm), larger compressor wheels (47mm), and higher a/r (0.85a/r). Claimed they were better than BNR's sequential twins and provided dyno proof but never sold them in large quantities (unknown). Just wondering if twins like this actually exist, and give BNR's a run for its money. Pretty interesting read if you check out his posts.

This is his account: https://www.rx7club.com/members/the-doctor-100221/

https://cimg5.ibsrv.net/gimg/www.rx7...94c064b50.jpeg

https://cimg4.ibsrv.net/gimg/www.rx7...6c6e87688.jpeg

There is a big thread on this joke already, spanning multiple years. Buy at your own risk. If they were magical, you'd see a lot of people running them, and real dyno data from someone other than mr doctor

Did you mean mythical? :lol:

I think the bigger issue with “THE DOCTOR” or MARCUS READ is that he’s obv invested a lot of money into dyno days and getting his product out there but refused to spend 10 dollars on a new keyboard that doesn’t have a broken caps lock key.

I think the bigger issue is that he’s just full of shit.

Marcus carries better stock than Mazda Australia of FD parts, I have held several generations of various high flows in my own hands including twin GT28Rs he has played with. They are legitimately larger and more modern turbines and compressors, they will undoubtedly flow significantly more than BNRs choking factory turbine wheels. You may not like his online persona but the turbo and relative power over factory turbines are legit. Obviously any particular dyno may read differently to others but if you are suggesting turbines with something approaching 50% more flow area, better downpipes and exhaust and better than SP intercooler/ducting won't make significantly more power you are full of sh1t/a one eyed BNR groupie. Likewise claiming a mainline or dyno dynamics in Aus is more optimistic than a mustang will get you laughed out of any room you care to enter.

Billtech amongst several other shops who have tuned for his customers are legit and tune rotary and numerous other cars.


Do the sums on effective compressor and turbine flow area vs modern 35r variants or similar, it's not rocket surgery.

Edit: just thought I'd add, I have zero interest in twins personally (have an original 35r and upgraded rotating assembly as well as a G40-1150 to try once I have sorted all my reloading stuff and given my block a birthday) and no financial affiliation, just collect parts in the flesh occasionally.


Pretty sure sure Marcus did pretty all the work on turbo Dev in the first place before they parted company.

For the umpteenth time, THE DOCTOR (aka, Sasha A.) & Marcus Read are not the same; two different individuals who did happen to work together at one point apparently; hence, possibly the confusion re: the Aussie pair.

Note: I have zero association w either RX7 enthusiast, but wanted to clarify some of the lazy takes and or misinformation from anybody equating the two.

I agree that if the listed turbo numbers are real then they add up to that performance level. Certainly capable of ~245 rotary hp each. What I’d question is if the manifold and other OE components are possible of it or not. :dunno:
.

They both have broken cap lock buttons? Some coincidence that

Again, both real people, I buy stuff from Marcus regularly, I bought a billet GTR coil kit from Sasha, collected in person.

Who's Marcus?

They are just 2 different people that make/sell stuff. Marcus sells cool stuff. Sasha is the guy that refers to himself as THE DOCTOR (surprising haha) and makes claims without ever providing data or videos to support it and says everyone else's stuff sucks. If the turbos were really that magical, there would be a whole lot more of them.

Appreciate the clarification. :icon_tup:

I had a half hour conversation with him over chat about his twins.

"faster than a 600hp Single"

Ok, show me a dyno

"Oh I don't have one matey, just trust me"

On and on.

Asked for back pressure readings, dyno, literally anything with a standard 5252 plot that could back up ANYTHING he claimed

Instead, he sent me pictures of him in Japan, saying "trust me matey it's the best"

Eventually after 45 minutes of asking, he admitted "350-370hp" is standard for his twins....

Yeah. Wasted my time, total snake oil salesman.

Odds are they don't have some secret sauce, especially with technology from 20+ years ago.

For that power range, might as well go with 99 spec. Better spool and should reliably support 350hp.

99 spec will make 370 when pushed. Like he said, 350-370hp, and with his other claims even that is seriously suspect. I'm beginning to doubt there's anything special about them at all

But it was the way he tried to sell, claims without proof etc dodging questions saying "TRUST ME MATEY" that really put it over the edge. Definitely not a guy who believes in his product, just a dude who really wants to sell to anyone who's got a dollar. No customers willing to dyno, his own car isn't running now, only dyno has weird scaling etc etc. I was laughing while trying to get the actual info from him, but looking back on it it just pisses me off. I'm sure good people have lost money listening to his bs.


What's the ethics of sharing a text conversation between yourself and a vendor? Cause I'm really tempted to air out his BS but at the same time I haven't given him money and it was a closed conversation. I should probably leave it as "go ask him for proof yourself and see what he comes up with to dodge the question".

99 spec twins, BNRs, Rmagic ball bearing primary twins and even these "magic" twins are an incremental improvement over the standard FD twin turbos.

The standard or '99 spec twin turbos are around $3,000 brand new, so any incremental improvement is hard to swallow at $5,700 (the cost of the "magic").

There is also the Hitachi HT12-3KAI's, which I have and several others on the forum have. I don't see that they are still being produced. I bought mine around 7 years ago. These were produced by Hitachi themselves to improve on the 99 spec version and were sold by GCG in Australia and a few vendors here had them also, such as Ari at RX7.com.

-10-12% more air flow due to the larger intake turbine wheel 43.2 mm vs. 41.5 mm, exhaust wheel the same as all the other versions
-shaft is 40% thicker for less wobble and much greater longevity
-*most important*- seals are 360 degrees rather 270 degrees- makes a huge difference in longevity and oiling
-housings are redesigned with different shape but similar volume
-*second most important*- the wastegate is larger (Wastegate is 27mm vs. the previous 25.5 mm. This can allow about a 20% more exhaust volume to be vented away from the exhaust manifold when it is fully open.) which means less chance of overboost and better boost control
-actuator are better and upgraded to take higher boost but unfortunately same spring rate (I switched mine to custom Forge actuators with changeable springs)
-flow maps are improved
-these were developed to run up to 20 psi, which is unfortunately limited by the stock manifolds, but can run 16-18 for long periods and have again much greater longevity even at these higher boost levels

Mike

Again, probably a perception difference between 370 "American" horsepower and what a DD or mainline reads. There is also a realistic limit to what people will make with a relatively stock engine bay and target boost on regular pump fuel. If you go to race fuel, flex, water injection there is significant head room on those turbos. Not my interest but people seem to be expecting better than a modern single with stock ports/intake manifold from sequentials at pump fuel boost, that sounds like moron factor at the potential customer end rather than retailer?

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https://ibb.co/41qcQ3D
forum uploader keeps failing when I try to add the timeslip?
https://ibb.co/41qcQ3D

Never knew about these twins, they sound like a nice improvement. Since a big limitation of the twin turbo setup is due to the stock exhaust manifold, I wonder if it can be ported enough to be less of an issue.

I wonder if these are what other aftermarket companies were using in the past as well such as Knightsports. I'm going to have to go down this rabbit hole eventually as I plan to keep my car sequential but know my stockers will only last so long. I don't plan on breaking 350 so response and longevity are key points in my search.

I thought they were discontinued.

The Hitachi HT12s are supposed to be discontinued. Maybe some has a set or a few stashed.

It's a ton of money for random time slip and a "trust me matey" as the only available "data". If they were that good, people would share info. In general, people share data when it's impressive, and don't share info when they are embarrassed about spending money with crap results. There is no data available from Marcus either as the seller, just excuses as to why he has none.

10.7 et is fast for twins.

15 years ago tom94RX-7 did 10.87 et on stock stock twins (411rwhp dyno).

Thats why I say, incremental improvements..

https://www.rx7club.com/time-slips-d...turbos-954861/

Yes it it.

But Marcus also told me his car isn't running now (another reason he "can't" provide a dyno) so I don't know how sustainable those power levels are..

I hope we get good data to back it up and they really are as good as they are claimed to be. I'd rather be wrong than right honestly, big power twins in an FD is a very cool thing.

^Interesting feedback. Just to be clear, your direct interaction was w Sasha or Marcus?

I don't know if Hitachi even makes turbos at all anymore. They probably exited the business a while back.

Post count booster, ha.

rx72c was running the FD Motorsport twins on his personal car a couple years ago before they became unavailable and should have a dyno if you want to trawl through facebook - running a pulsar now?? I see Sasha was flogging a set of "refurbished" ones a few months back, which might amount to bead blasting, or maybe he still has some cores there if desperate?

From what I recall from other tuners, 270kw@1bar on petrol seems to be typical with these (Dyno Dynamics), with the SP covers installed. If you suffer from potential illegalities with a single, probably the best bolt-on option out there.......fucking around with bored out side feeds nowadays though - yuk!

I haven't seen the 3KAI's listed for sale for at least 4-5 years, if not more. I am lucky mine are still in great shape. Raymond, you are probably right that Hitachi is out of the turbo business.
Mike

He has a fair few customers with them running ethanol around 25psi. Would be hard to argue worse life than overspeeding factory or KAI turbos on the small shafts. His personal car is an SP (so arguable leaving it on stands is an investment) and he usually has imported RZ Rx7s or GTRs to drive around if not driving the falcon.


Where is this "can't provide a dyno" coming from? He regularly shares dyno charts on Facebook.


faxtory form twins is really a niche thing for people who want period correct or very close engine bay or have class limitations, in that context stuff is generally expensive for marginal gains, given the price of new standard turbos it's to be expected. Again for most people I don't see the attraction, I'd rather use the logic control to use the secondary runner throttles vs rpm and run a split pulse single turbo.

This thread is a scam and waste of time just like the other one. No point in debating this endlessly unless someone actually has a video of a car running them on a dyno and/or track with time slip. There is a reason there is no data only snake oil claims. Would be happy to be proven wrong here, but this has gone on for years.

Marcus

He would make more money advertising a product vs waiting for a car to age.

Look at the dynos on Facebook. They all lack data, weird scaling, no ft/lbs, screen shot is cut off etc. There is no clear standard format HPxFTLBS showing boost. Please show us a good clear dyno, I would like to be wrong. But a 45 minute conversation with Marcus directly lead to zero actual data, if he had any he would have shared it. Instead, he just showed me pictures of him in Japan. Maybe Japan has a Visa category for "exceptional aftermarket parts" that I somehow missed?

Yes, my point exactly.

(Show us the engine bay Squiggles, your V12 quad turbo e46 is a lie)

I've seen the posts on Facebook but it looks like its been the same dyno/car for years. I'm not "nay saying" but I agree with the rest, it is suspicious. I am probably one of the few hopefuls for these twins as I am one of those you mentioned that is in that "niche" group of wanting to keep the nostalgic sequential twins and will be looking for replacements at some point. I am 100% sold on the Stock mount intercooler that both Sasha and Marcus sell and plan on grabbing one in the somewhat near future. I'm also 100% behind the vision both of those individuals like to push with a great performing sequential FD as that is my personal preference and I like the vision and product ideas they have. I just need more reassurance.

The facts are, we are at an age where it would be super simple to take a cell phone video of these cars running these setups at the dyno and post them. If they can do that and provide actual data, then they will have a new customer with me. But as others have said, that price is hard to swallow when I can grab a brand new set of 99 specs for half the price and meet my power goals. I would rather do something "beefier" that would probably last longer but its not worth that risk when I can buy two sets of brand new twins and stuff one in the closet until the other set dies in 20 years. Do you happen to know some of these other individuals that run these setups personally that you can ask if it is ok to give out their social media or something? That way possible future customers such as myself can be able to do more due diligence in researching the investment. I know I personally would be ok with somebody asking me about my experience with a product I am using, especially if it is in the rotary community. We honestly need more support in the Rotary community to continue to make parts for these cars such as JP3, SMB and RaceOnly. I would be happy to support them and keep them in business if they are making a product as well as they say.

I only lived in Sydney for a short time and was never really in the scene there, I'm sure if you messaged one of the owners he tags on Facebook they could give you feedback. I know the Rotormaster/Gas Motorsport workshop has had a good reputation for a long time (and some fast drag cars too), maybe flick them an email asking for a vit of feedback on tuning them?

I have actually purchased my set of twins from Marcus, as when I was replacing my twins BNR's were on backorder and Marcus actually had his set cheaper than a set of new 99's. I paid 3500 AUD in 8/21 for them, and they were a set of rebuilt twins. I wish I took more photos of them, but alas I was too excited to install them. There was some cracking on the wastegate port, but nothing atypical from stock twins. I am running a PFC, with basic bolt on mods, and have had the car tuned at Sakebomb garage in Fremont, CA. I got the autoexe intake, a ARC SMIC, catless downpipe, Bonez cat, and RB catback. I also have Rmagic ingition if that matters at all. Here is my dyno sheet, Sakebomb said I had an exhaust restriction, which may be true from the cat, but I am also limited by stock (but refreshed) fueling.
https://cimg1.ibsrv.net/gimg/www.rx7...ab81c87407.jpg

Honestly I don't think my tune is that good, but I am currently running ~14 psi. Will most likely get the car re-tuned down the road and can update once that happens.

Additionally, partially because these were rebuilt turbos, I believe these are pushing a non-zero amount of oil into my intake. Every time I take my intake elbow off for something I see a decent amount of oil.

I don't think there is much point with high flows (beyond not overspeeding factory turbos) with a factory fuel system. I have a significantly higher flowing pump fed from a surge tank and high flowed secondary injectors, from memory I have seen injector duty peak hold on the handset in the 90s duty cycle with Apexi intake, U type intercooler, some Japanese 3 inch down pipe and a 3.5inch catback just on series 8 turbos.

Because, any actual measurements show it’s bullshit

https://cimg9.ibsrv.net/gimg/www.rx7...640c8427e.jpeg

Marcus, the definition of the rx7 clown of the web. LOL

It is beyond me that people actually support that fucking moron