Good memory. The RB+midpipe isn't too bad along as you stay sequential. IMO, the biggest problem is smell for the exhaust. Mrs. SleepR1 isn't going to like it. If you aren't going to track it anymore go with a high flow cat.

R

 

Who in Indianapolis is going to tune your car? You better get good help if you are going to run 15 lbs. And like I mentioned before I hope you aren't reading 15 lbs from the PFC display. I would guess the display (not the internal computer) is off by a good 1 lbs.

 

Smell can't be any worse than when my cat was failed anyway Mrs. Sleep doesn't like riding in my car...she gets scared easily Zavier Neeley and Jason Baughman are tuning my car at the Rx7 Store in Columbus OH. I'm having Z tune my FD to 1.05 kg/cm^2 (Power FC readout). In reality, I won't set the boost any higher than 1 kilo (14.22 psi) for stoplight street rodding Car will be picked up on Sunday Nov 2, so I'm looking forward to finally having a dyno plot of my car with all the mods listed plus MP instead of high-flow cat (air pump removed). Perhaps they'll post it on the Rx7 forum?

 

BTW, that's RTS3GEN's engine bay (as of last weekend).

 

I'm blinded by the sheer bling bling of the polished piping

 

Yep, unfortunately, the picture doesn't do it justice. You really can't see everything that he has polished and chromed.

However, his car looks like that all the time. Even after track events, it will be completely cleaned from head to toe in just a day or so. Then of course he checks everything out to make sure everything is everything...

It probably seems a little much, but that's what keeps his car going without having huge problems. We all run into those little things.

 

Thanks for the kudos, I have tracked the car for almost 5 years now averaging 7 to 9 events per summer. Reliability is all relative, fix the weak points and you'll eventually fix most if not all of the weak links. Temp is key but I think my luck has stemmed mostly from running full synthetic Amsoil oil and some other top secret additives I have used on Cameron Worths' suggestion. I run X1R in the oil also, every change I add a 1/2 bottle. I run Protek R in the fuel, and also run NO thermostat with 1/2 antifreeze and 1/2 Pro-Blend's " cools like ice water". Oh, yeah, I forgot to mention that I ALWAYS run 1/2 tank of at least 100 octane and 92 while on the track. Every bit of safety helps. Sleep, shoot me a pm and maybe we can come up with a solution or a improvement to your system. If not, good luck with your gremlins.

Art

 

Well you have a point but with all that extra weight you'll need to upgrade the brakes, susp, and add a single to carry those students around at speed. Soon you'll be praying for more 0% credit card offers to land in your mail box

 

Ok, I get it now

Perhaps people have the misconception that a "stock form" car is going to be more reliable than a race modded car...I believe this is the illusion you suffered from instead. The more you mod your car, the better it's going to run, both performance and reliability. The stock twins (especially running sequential) is a perfect example. A nice simple single will perform much better on the track and also be much much more reliable. Mazda could have developed the RX-7 a lot cheaper and easier if it skipped all the things that make it a very streetable car. These are the things that cut down on reliability, not racing mods. No racing car should IMO have sequential turbochargers as they're not designed for racing. They're designed for everyday driving.

I believe my car will be pretty bulletproof on the track when I've finished with everything. However, I have no delusions that my motor or turbos or suspension or whatever is going to last forever, even after all the money is put into my car to make a perfect setup, the parts will still eventually need to be replaced or rebuilt save only the apex seals (funny but true). So when I say bulletproof I refer to unexpected failures. So far with my project the motor is the only thing that's really been completed; I've eliminated the water seal problem with the heavy duty units. The ceramic seals will never need to be replaced, they'll put up with any sort of racing abuse and hold out against detonation long enough for me to back off and fix the problem with tuning. The housings are good for at least 60k miles of hard hard driving at high power levels (Rob gave me that figure if the engine was run at 550rwhp). The motor is also ported so I don't have to run excessive boost to reach my power requirements. I expect the GT35/40 turbo to last at least as long as the stock twins (60k miles or so) at 15-17psi on the street and 20-22psi on the track. I also expect to cut a lot of abuse on the engine with excessive air/water/oil cooling as heat is one of the rotary's biggest gremlins. That pretty much covers everything that sets the FD apart from other cars; everything else requires the same maintenance as any performance/racing car does. If you set the car up correctly from the start, it can be just as reliable as any other car, if not more given its small size/mass. The rotary proved itself once and for all in 1991 when it annihilated the rest of the field in the highest echelon of car racing next to F1, not to mention the most grueling at 24 hours straight, and after the race they took apart the motor and decided it could have run another 24 race back to back. It just goes to prove that if you prepare correctly, you can achieve your goals with this power plant and car.

 

I spoke to soon before reading the entire thread...looks like Crispy already slapped the sense back into you Manny I don't want to overwhelm you guys with all this text so I'll reserve my other comments after a few other people have posted.

 

If I hear one more time about the rotary winning ONE 24 hour race at LeMans over 10 years ago (and save me all the "we'd have dominated if we weren't regulated out of competition hoopla) I am going to . Yes it was a great victory for Mazda. But if that one victory is such the basis for Mazda pride than Porsche is kicking the entire world's *** and therefore must have the best engines and cars on the planet; bar none. It doesn't work that way. (and I will leave out the current mess with the Renesis. Wonderful new technolgoy that brings us much less power than expected and still nearly horrible gas mileage. The apple doesn't fall far from the tree). Can someone remind me how many turbos were on the LeMans entry? Two? One? NONE?

Just as you pointed out that a street engine and a race engine are two different systems, you seem to forget that when talking about the race engine in the LeMans car. I am sure that engine saw a level of materials and preperation that has and will never exist for a road going Mazda car. Mazda acheived their goals with THAT powerplant in THAT car. A 13B is different and is only a cousin to the LeMans engines.

Everyone here who has lost apex seals or coolant o-rings on stock motors please raise your hand. Man, did ALL of you guys overheat your car or have improper tuning? There's just too many of you to say that ALL of you screwed up...

 

 

I don't understand why your engine doesn't overheat without a thermostat. Most Jap and American thermostat set up allows a portion of hot side coolant to bypass back to the block when the thermostat is closed. This bypass port is a hole that faces the thermostat. As the thermostat opens it moves towards this hole slowly closing off the flow going straight back to the engine. As the thermostat fully opens, it closes this hole and all of the coolant must flow thru the thermostat to the upper radiator hose.

Without the thermostat, this bypass hole never closes and a portion (30%???) of your coolant goes straight back to the block. I found this out when my car overheated on a cool day running without a thermostat. During rebuild, I took apart the housing on which the filler neck is mounted and saw how the thermostat worked. Confirmed this with the tech people at Evans.

Anybody has an explanation that disproves my observation and proves that no thermostat is best?

 

The guys I have seen running no thermostat plug the hole you speak of along with running a restrictor in place of the thermostat.

 

Use a "drilled" thermostat and you get 90% of the benefit of running with a thermostat and 90% of the benefit of running without one at all.

Two things I found to be most critical to reliability cooling and boost. Get those two under control by however means necessary (single turbo or simply turning down the boost and performing every possible cooling mod you can) and you car will *survive* the track because that's all it really is.....survival.

Crispy

 

Rough dyno tune done @ Rx7 Store's Mustang Dyno yesterday (Nov 2). Tuning was done by Jason Baughman and Zavier Neeley. Used up most of a 2/3 full tank, ran between 7 to 10 dyno pulls, and 3 hours 45 minutes (read lots of heatsoak), we got a safe tune with AFRs in the 10s/11s as read from the lambda sensor in the RB DT's tail pipe. Base hp with MP no adjustments to Dave Barninger's base map was 285 rwhp (14/15 psi). AFRs were 10s. Jason leaned out the AFR to 11ish, and we got 306 rwhp with 15ish boost. Jason tried advancing the timing a skosh, with a resulting decrease in hp, so Jason backed the timing back down, resulting in no changes in the ignition timing from Dave Barninger's base map--Dave retarded the ignition to take advantage of the healthy street port he gave my motor. The Power FC tends to run in nonsequential mode with rpms from 3000 on up, so the dyno plot looks similar to what a single turbo motor would like like--lots of power in a very short time from 3800 rpm to 7300 rpm. Dave's healthy streetport gives my motor lots of midrange pull, with rwhp decreasing as engine speed exceeds 7000 rpm. Peak hp was read @ 6750 rpm, 306, and peak torque was read at 4750 rpm @ 273 lb.ft. With Power FC boost set to 1.05 kg/cm^2 (15 psi), we did see spiking up to 1.15 kg/cm^2 (16.4 psi). On the road with cool AITs (30 to 40 C), the car feels STRONG at 0.80/0.85 kilo/cm^2 (11/12 psi) boost. The midpipe, has a very raw sound and feel, especially when you get on it. Autocrossing will never be the same...it will be more like drift practice Oh, and yes, I wreak of exhaust fumes after a trip in my new "street rod" I applaud you all in keeping the faith with road racing the FD.

 

When I first read this I was truly disappointed, but then I read it again and discovered that you mention the use of a Mustang dyno. If I recall don't those types of dynos under rate the typical dyno (like the one that KDR uses)? Based on what I believe you've done to your car I would assume that you easily had 340 hp to the wheels.

Ramon

 

Yeah, I was disappointed too. I was hoping to build a car like yours!

 

Hey Ramon, how is it that different dynos yield different hp readings? What is Dave Barninger using @ KDR? What did your FD dyno at (and what psi)? We have just about the same mods, except for my '99 J-spec twin turbos.

 

It is my understanding that a well sorted out FD with stock/99 spec turbos running 13-15 lbs can make 350 rwhp. (BTW, I wouldn't suggest doing track events at that boost with your turbos). This number I believe comes from "Dynojet" dynos. I wouldn't be surprised if a lot of shops used this type of dyno. The inertia dyno you used is called a "Mustang" dyno. They work differently or so I'm told.

In any case I bet your 306 rwhp on the Mustang = ~335 on a dynojet. That's pretty good.

BTW, I haven't dyno'd my car.

See the following thread started by Tim Benton. He has your setup and got 360's on his 99 spec turbos.

https://www.rx7club.com/showthread.p...ght=spec+turbo

If you are not sure about your power go back to Road America and see if you can hit 5th gear like I did before Canada corner :-)

PM me if you need more info.

Ramon

 

You take a 13mm freeze plug and rough the edges up then you plug that bypass hole so there is no recirc of coolant. Once you have hammered in the freeze plug, you take a sharp metal chisel and stake it at 10o'clock, 2 oclock and 6 oclock position so it doesn't swell back out. The bypass is typically used for faster warmup to aid in cold start emissions, not needed on a road going race setup. Also, if you haven't tried the Problend "cools like icewater" then you are truly missing out on one of the best cooling systems one can use. I have been road racing my 7 for 5 years on the same engine with no cooling issues to date, even in 100plus degree temps. I have tried every imaginable combination including Evans coolant, which I might add was the hottest my engine has ever seen, I record every event in a log book and the ambient temp as recorded in the paddocks was 103F. My engine temp at peak was 253 degrees F at 9psi. I did note however, that the car was running flawlessly. With only 92 octane gas at this temp there was no pinging or detonation. And inspection of the plugs confirmed this with a nice dark brown coating on them. So, my observation was that the Evans coolant worked by not allowing any hotspots BUT, was allowing the engine to run a higher temperature safely. BUT, by comparison, this past June, running 50% Problend and 50% antifreeze/water mix and ambient temps at 102F, my highest peak engine temp was 227 degrees F. and running 11.4psi boost. The proof was in the pudding for me. FWIW.
Art

 

To add to my post in regard to pomanferrari's last question, in a road racing environment, much to Crispy's response, you are just trying to keep the car alive. When you are generating very high temps for extended periods you need to dissipate the heat as fast as possible, therefore you need as little restriction in the flow of water to the radiator and back into the engine to cool it. If you have a suitable radiator that is all aluminum and gets ample supply of air(ie ductwork) a thermostat will hold the water in the block longer and therefore pick up more heat, but this is where it gets tricky, the radiator will only dissapate a given amount of heat in that short time it is flowing thru it. Since most radiators flow via gravity once fed into them, they will all cool at the same rate, but remember you have the thermostat in place and you are picking up more heat and becoming less efficient at dissipating it thru the radiator. Now the laws of thermodynamics take over and tell you the heat not lost becomes almost additive to the heat you are keeping in the engine by allowing it to stay there longer. Then the longer you drive the system in this manner you will reach a point where the slow water moving thru the block and the fast gravity fed cooling radiator can no longer generate the "normal" heat gradient by which to dissipate the heat and "BOOM" nice meltdown. Without the restriction of the thermostat, you can move the water thru the block and the radiator at almost the same rate and thereby keep the temperature gradient more consistent. Got it? NO thermostat for long enduro and road racing.
Art

 

Where do you get the Problend, and what is it chemically? Is it ethylene glycol/water-based?

 

Ah...well, my car "feels" faster than 306 hp...but I'll just tell people 300 "Mustang Dyno HP" at the wheels. I wouldn't be lying

 

Ramon, checked out what you posted about the Mustang Dyno reporting a more "conservative" dyno number than DynoJet. Apparently others agree. rynberg's results show 11% less hp with Mustang Dyno.

I guess my 306 Mustang dyno hp would be 330 to 340 DynoJet hp?