Its alive!!... v.RX7

[Jims5543]

In March of 2006 I overheated the engine in my RX7 at a 2 day DE in Miami. I cooked it.. bad... 280 degrees bad I even melted the injector deflector/atomizing tips in the engine along with the solder slugs on the side put on for warranty monitoring. Yeah that one was void.

So we decided to make it stronger, faster, meaner, oh yeah, and run cooler.

We did what is called an agressive street port, this is a rotary version of a port and polish but like everything else in a rotary, it does not just get you a few more ponies it gets a LOT. We are expecting a 25% increase in power from this port job.

The unfortunate part is that when you port this deep you cut into the water jacket. We sealed it back off using a $90 a quart epoxy that failed once it was brought up to 200 degrees in water. Worse part was that it happened after we put the engine back to gether and were breaking it in.

JB Weld fixed the problem, go figure.

So now it back together with a HUGE fuel system inplace that will support 700RWHP, engine built up to handle 25PSI of boost and all kinds of go fast upgrades to the engine.

Dont forget a 9.5# flywheel to replace the 23# one.

Se we started it up for the second time today and I brought my laptop over so we could trip the fuel down 10%. I run a Motec M4 ECU in the car.

Here is a short clip of it starting up and back ing out of the bay for me to tune it. You can hear the wine of the Be Cool fans and fuel pump just before it starts up.

The smoke is normal on an new engine it has not sealed up yet, plus we are running a lot of premix in the gas. Think 2 stroke engine. Premix helps with premature engine wear in a rotary. Mazda injects crankcase oil into the engine but the better way to do it is to premix like a 2 stroke. Unfortunatly no one would buy the cars if they had to do that.

The Video, I am giddy with excitement.

[onewhippedpuppy]

Very nice, sounds mean. So do you need to change your sig to 2500 lbs 500RWHP? I look forward to more stories of suprising expensive cars on the track.

[Jims5543]

Actually I am in the market for some "track Doors" = doors off a doner RX7 to be stripped down to nothing. I am removing the Power Sunroof motor and associated crap along with some other weight savings. Shooting for 2400 lbs or less.

We are expecting 450-470RWHP due to the turbo not being big enough to make any more power. I have a GT35R in a box needing a manifold. Once she is broken in and tuned we will look into putting that on. Its a better turbo for that elusive 500RWHP.

[kaisen]

Congrats! I've always loved seeing your car and appreciate the updates you give us from time to time

[Dantilla]

What a great ride. Thanks!

[Rick V]

Sweet! Bring that puppy to Fontanna this Nov. I want a ride. And for those not knowing this is what an RX looks like in the throws of death. Sorry Jim, I couldn't help myself.

[kaisen]

Smokescreen? Did Q issue you the RX7?

The name is Cesiro. James Cesiro.

[Jims5543]

Originally posted by Rick V
[B]Sweet! Bring that puppy to Fontanna this Nov. I want a ride. And for those not knowing this is what an RX looks like in the throws of death. Sorry Jim, I couldn't help myself.

LOL!! See the camera on the roof? I have footage of that little outing.

To tell the truth, that was the 1st session of the 1st day. I was baffled why the car was throwing so much smoke. Once we tore down the engineit was apparent why. The last engine rebuilder used popsicle sticks for feeler guages when clearancing my side seals on my rotors.

There was so much gap on them that they were pulling engine oil through the combustion chamber.

Rick- Honestly, you REALLY want a ride in this thing? Think of my 911 on steriods. You kept saying it felt like the 911 was going to break loose, I can honestly tell you this car is that X10. It will scare you to death.

I no one minds I might bring it up this year, my only problem is I am bringing my 911 up on the 28th to leave for the summer. I'll work it out.

[Jims5543]

Here is the "Smoke Cam"

Watch for the CGT right as I shoot some flames.

[kaisen]

Mmmm flamebroiled

[stomachmonkey]

Originally posted by Jim Cesiro
Here is the "Smoke Cam"

Watch for the CGT right as I shoot some flames.

Had an 80', my brother had an 81'. That car was an absolute blast.

Have never driven a car that was as easy to throttle steer. Just damn good clean fun.

And so easy to get HP out of. The backfire/shooting flames thing was a blast.

Coming home one night in a light rain and from out of no where a black 911 (of all things) comes charging up my ass. But we are coming up to a light that's going red so I slam it down thru the gears and BANG, I get a huge backfire and flames out of the tailpipe. I can see them reflect in the 911's hood. I think it scared the crap out of him because he did not come within 5 car lengths of me after that.

Do you know Steve Stander?

Last I heard he was involved with the Mazda Speed program?

Waaaayyyy back in the day he was one of the first guys tuning RX 7's.

He had a shop here in NY called AutoTrix.

We were friends but I lost track of him over the years. He was a good guy with a passion for the brand. He built that 10th anniversary edition TT that set a record at Bonnevile. He and my brother used to go down to Englishtown and embarass guys with 5.0 mustangs. My brother was running a worked Turbo MX6 at that time. Use to piss guys off getting beat by a FWD Japanese 4 banger.

Scott

[Rick V]

Originally posted by Jim Cesiro
It will scare you to death.

Now I gotta ride. You should know me well enough to know I don't get rattled too easily. Besides you can only kill me once, if you do I won't ever ride with you again.

[Jims5543]

I dropped my 911 off at my mechanics so he can make me a custom little part for it and drive the RX7 back to the office.

I noticed right away the 9.5# flywheel. Actually that would be when I stalled it. I cannot get into it yet but driving it for the 1st time in 15 months after only driving the 911 was interesting.

The seating position is a lot higher in the RX7 both off the floor of the car and off the actual ground, after being in the 911 for so long it almost felt like I was in a pickup truck.

I took a 90 degree turn pretty fast, in the 911 you feel like it squatted down in the rear and dug in, the initial turn in on the 911 is remarkable, but by mid turn you feel like your coaxing it through the turn. In the RX7 the turn in is not as sharp, but the rest of the turn is very light, the car wants to turn its feels so much more balanced at mid turn.

It was fun driving the monster again even though I could not give it any boost it was still fun to cruise along in it. Although that lightened flywheel has forced me to drive differently. I cannot ride in a higher gear at low RPS or she will buck right away, so I am finding I have to drop a gear lower cruising to make her happy, anything below 3K RPM pisses her off, remember, redline is at 9K. Power comes on hard at 4K.

Good to see the old girl back in the parking lot at work.

But I still prefer to drive the Porsche gives hands down.

[kaisen]

Cool Jim. When you get her broken in and sorted, make a video!

[TimothyFarrar]

Jim,

What do you do about knock control? Don't those apex seals crack easily?

[Jims5543]

You tune differently. In other words you set your timing maps, boost and fuel conservative then ease your way in. It takes a long time to dial these cars in.

The guys breaking apex seals are trying to set records.

I just want a fast car, I really try not to chase horsepower when tuning. We usually do a pull or 2 on the dyno to check the A/F ratios, tweek, do a few more pulls playing with the boost, timing a/f again. Then go out and drive with the lambda turned on and tweek the fuel maps in the real world.

Tuning will take a couple of weeks.

She feels really good right now and for having only 200 miles on the engine it feels really strong, even though it is not fully seated in yet. I hope to rack up about 5-600 more miles then we will begin tuning it.

The engine will survive a slight ping / knock but will not survive prolonged knocking. Like I said you ease your way in really slowly and really try not to chase the numbers.

Edit because I can even trick spell check with my pathetic spelling.

[dd74]

Maybe I've asked this, but what are 3 and 4-port Rotary engines? I've seen them mentioned on Mazda-related websites.

[Jims5543]

Originally posted by dd74
Maybe I've asked this, but what are 3 and 4-port Rotary engines? I've seen them mentioned on Mazda-related websites.

I am not exactly sure of the question but here are some answers.

There is what is referred to as a 4 port or 6 port block in the 2nd generation engines. If the car was non-turbo it has a 6 port engine that would run initially on 4 ports then open on the 2 extra ports at higher RPM's to create better airflow and more HP. It only ran on 4 ports at low RPM because this made for more torque in the engine.

The straight 4 port setup was for the turbo cars because they did not need the aid of the 2 extra ports to make HP up high, that was what the turbo was for.


Now if you were talking about 3 or 4 Rotor engines thats a whole different story. 3 Rotor engines were found only in Japan in the Cosmo, a popular thing to do in the RX7 world was to get one of these 3 Rotor (or coded 20B) engines and swap them into an RX7. They were 2 liter twin turbo and factory rated at 270-300HP. They easily made 500HP with the stock turbos once tuned.

The 4 Rotor was exclusive to race cars, they cost about 80K each and guys like Roger Mandaville and Jim Downing ran them, Downing ran them in the Kudzu chassis in the AMLS. This was also the engine that Mazda won the Le Mans with in the early 90's.




I just dropped the RX7 back off and picked up the Porsche. Driving one, getting out and driving the other is really cool because both cars are so unique.

I took that same turn in the 911 that I took earlier in the RX7 and can say that it is obvious which car has a upgraded suspension and its not a fair comparison. That said the Porsche felt really good through the turn even it if did have a lot more body roll. But comparing the 2 is apples and oranges.

Both attract a lot of attention but from different people. The RX7 tends to draw attention from 18-24 year old boys where as the 911 gets look from the same 18-24 year olds but then includes 25+ men and some women.

The drive in the 911 is much more fun no matter how you look at it though. Its just a very enjoyable car to drive. The RX7 is fun too but not nearly as much as the 911.

I was happy to drive the 7 again after 15 long months.

[dd74]

Hey Jim - Thanks for the answer. I mistyped the question. I did mean 3-rotor and 4-rotor engines.

Thanks again.

[sewell94]

Jim,
Which dyno are you tuning your car at?? I'm curious, because i'm the only i know of locally that has a dyno that actually loads.


It's great to see your Rx7 back up and running.