Charles R. Hill

iTrader: (7)

Marietta8, who owns his own shop in GA, told me about that one.

rotarygod

I guess it's only impossible until someone does it. Having one dent just from boost at hose levels is a new one on me. That's actually not that much boost when it comes to denting rotors. I'd be curious to see more info on that and the circumstances of it. Marietta is a good guy so I'm not going to claim bs on him. Just that it deserves more attention before a true conclusion can be determined.

rotorocks

I boosted it to over 15 once (Oops, by accident ) ...Nothing happened.
14 PSI happened 3 or 4 times earlier, when I was playing with the boost controller.
And I can't say my tune was that good.
I am sure that properly tuned and fueled, it can hit 20# and more.

Rootski

iTrader: (1)

Do it! I'd make the drive to Michigan to be a customer.

Jedi54

iTrader: (7)

I say prove the guy wrong! Either go with the Mazsport or wait for the AFSC. The reisis CAN handle boost, some ignorant people just won't accept it.

Charles R. Hill

iTrader: (7)

Rootski, it wouldn't be a problem for me to travel to Norwalk and do a project, or two, with you if you like. Most of my tools will can along in my trunk. I already have a trip to delaware planned for the 25th of Feb. and maybe another halfway around the World.

Rotor, what makes you so sure on the 20 psi+?

rotarygod

Boost pressure as a number doesn't tell you what pressures are going on inside the engine during combustion. Remember not all turbos flow the same amount of air at the same pressures. It's the amount of air in the engine that matters, not what pressure it entered the engine at.

Charles R. Hill

iTrader: (7)

Yeah, the details like where the boost pressure was measured and so forth were not part of the story but if I had a turbo I would be cautious just the same. RG, based on the ideas you and I shared before I went with nitrous I would be comfortable until levels over 12 psi. Then I would be careful.

rotarygod

I'd be willing to take a car up that boost pressure with the right turbo but after about 1 bar, I'd really be considering either alcohol injection or a much higher specialty gas.

Charles R. Hill

iTrader: (7)

I tend to consider water/alcohol injection as a bit of a band-aid solution, as opposed to using higher octane fuel, but that's only because of the added hardware and not a criticism of the idea itself. Like nitrous, it seems that very few people understand the purpose and how to install or tune it correctly.

sburkett

A little late but to back up rotarygod's earlier post, one of my customers made 603 wheel horsepower on a 13B REW with stock internals and 2mm seals. No problem, would have kept going but his boost controller couldn't hang past 28 psi. 500+ rwhp on a 13b is expensive, but it's almost cookie cutter to pull that off now.

I will be tuning with VP Import for my Renesis project and at 120 motor octane I think I'll be able to run some serious boost. Will also be doing a pump gas tune, but I don't really intend to drive my car on the street much.

Otherwise, concur with everything RG said here. We'll see what breaks first, but it won't be due to detonation, and I bet it won't be seals.

Steven

rotorocks

@15 PSI measured from under the throttle body, when it spiked up that high, the engine did not even flinch, it just gracefully took it. It was back at the beginning when I just built the system.
I never run it at such high pressures, on purpose. The highest I did for an extended period of time (through the time it took me to accelerate to the 65 mph, as per the posted speed limit ) was 12psi.
Nowdays because I had lost my map, and I am working on a new tune I completely shut closed the boost, so the car runs at a max of 6-7 psi.
There is no specific justification to the 20psi number. It is just I have my faith in this motor.
It is not the pressure that destroys the engine, it is detonation, and if every measure is taken to avoid it, I don't see why Renesis can not be boosted to this levels, or higher. Especially if it is built up.

TeamRX8

iTrader: (25)

the trans and diff can barely handle the OE power level so I have no doubt that parts will be flying

sburkett

Diff will be a Ford 9" I think that will be okay . The RX-8 tranny is junk, but I'm going to see how much it can take on the dyno, and probably have to upgrade before I go to the strip. The transmission problem is going to be a pain in my butt no doubt.

nycgps

iTrader: (1)

Im a noob in these but Im curious what can we do to help the Tranny problem ? I know I can change the rear diff to something else (stronger perhaps) but Tranny .... which tranny actually fits ?

Charles R. Hill

iTrader: (7)

I have heard such things about the factory tranny and diff but I can guarantee you that I have probably hammered both of mine as much as anyone on this forum and they are fine. I've even kept my foot in it during nitrous use with wheelhop just to TRY and wreck the diff but it didn't happen. From what I remember the factory trans was good until around 400 h.p., where the input shaft snapped. Next comes the PPF and rear axles at about 450, and the rear lower links bend at 600. I am working on new axles and a replacement link set out of titanium right now. I should know for sure about both in the next week or so.

Of course, pressure alone is not any way to evaluate the rotor faces' durability. However, the intake charge has to light some time and that is where the concern comes in. At 20 psi, setting aside details, you're talking 2.3 bar. That might be a bit high but who knows(?). We'll see soon I guess. Lemme get to that 150 shot in the next couple months and I'll have something I can discuss with credibility.

Greddyturbo1

Good info here guys , we are probably not going to answer the question, if the Renesis is good for higher boost today, hopefully we will find out shortly..

The question I have is - Since the Renesis was in development prior to the release of the 2003 RX8, and if this engine was the hottest new Rotary engine, Why didn't Mazda install this Renesis into the 2002 Rx7 in Japan. And market this as a major advancement in rotary design and still keep the RX7 going...I'am still thinking the the Rx7 which was made til 2002 was not such old technology since it was only one year later till the Rx8 appeared, I know there is alot of people saying the Renesis is the stronger motor and from very well respected members, and I don't mean no disrespect, but I 'am still not sold on this idea. I hope the info keeps coming in, Thanks.

Charles R. Hill

iTrader: (7)

A few years ago, as I was researching the nitrous idea, Rotarygod and I spent a little time examining the details. He came from a mechanical/technical standpoint and I was coming from a philosophical one while also having a bit of performance street/racing experience. We both came to the same conclusion; that the Renesis would HAVE to be a better all-around engine than the previous 13B in order for it to be worth all the hoopla and fanfare. This is coming close to your own thoughts, Greddyturbo1. I would venture to say that the reason Mazda did not cut the Renesis loose on the RX-7 was that markets, especially in the sports-car world, are very sentimental and don't like changes that often. Thus, Mazda introduced the Renesis in a market that would be accepting of the new technology. It was thought by Mazda that the likely market for the RX-8 would be those who always wanted a rotary-powered car but could never afford one until now or people who used to have an RX-7 but now have family concerns. In either case, those particular people are far more forgiving than would have been hardcore enthusiast RX-7 owners, whether in the U.S. or Japan. Would you have believed that a new N/A 13B could ever develop as much h.p. as a TT 13B? Or hold up to repeated 9K hammerngs? As it turns out, several durability concerns that applied to the RX-7 engine do not apply to the RX-8 engine. However, it appears that some other parts, like the e-shaft, have remained the same and might even be more durable due to advances in metallurgical technologies.

Brettus

iTrader: (2)

why would they put a new motor into something they were just about to can ......

Charles R. Hill

iTrader: (7)

That, too. Good point, Brettus.

Greddyturbo1

Your probably right,I'am still learning.. Does anyone know what the price of a 2002 RX7 would cost in US dollars, in 2002.. I'll try searching, just want to compare pricing versus the RX8...

MazsportScott

I started to type a list but it grew to 20 reasons in less than 30 seconds so I stopped. My personal opinion is they should have offerd a n/a FD in 93, the lower cost combined with the sexy looks (still have yet to hear anyone say "Damn thats an ugly car") meant they probably would have moved more units. That said I believe the Renesis is a very good engine. The fact is, I have knocked on the 400rwhp door and opening that door is right around the corner. Have faith, although major changes in engine design has required some rethinking to the traditional approach to rotary performance, your Rotary Rocket as it sits and waits for you to "pull the trigger" is a very capable and reliable platform. Scott

TeamRX8

iTrader: (25)

LOL, anybody who has seriously competed with this trans knows it blows up, even Mazdaspeed Motorsports admits that it's very weak

california style

which part of thre trans?

As people here who know me realise, I am teh mechanical numpty...

By weak trans you mean the part after the clutch before the differential on the rear axle? or what?

please dont hurt me!

phartknauker

Im also interested in what part of the trans is "weak". Im ready to go forward with my plans to buy the Pettit SC and would hope the stock tranny will hold up.