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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.
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
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.
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 ****/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.
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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.
They both have broken cap lock buttons? Some coincidence that
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.
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").
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
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?
forum uploader keeps failing when I try to add the timeslip?
https://ibb.co/41qcQ3D
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
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.
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.
Mike
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.
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.
03-22-24, 11:53 PM
