fxdsconv2000

From the Stage 1 post I've read it "kicks in" at around 5000 rpm. My question is why? Wouldn't it be better to "kick in" at say 4000 rpm?

Since 4000 Rpm is 80 mph in 6th gear and this mod basicaly leans out the mixture, wouldn't we get better gas mileage and more power at the 4000 mark. Therefor at adverage highway speeds have better fuel use and more power for passing.

Or lets say your crusing around at 65 in 6th gear and you want to pass. You drop down to 5th (4000 rpm) and have the extra power needed for passing.

Would this cause premature engine wear or damage the engine in anyway?

Maybe this could be a Stage 1.5

RX-8 friend

It's very simple. It's actually closer to 6000 RPM. Mazda's stock programming was fine up to there, then got very rich. Stage 1 fixes that and cleans up the mixture at the intake transisions as well. I think it also leans out the idle a bit. See the dyno graphs elsewhere here. Basically, Stage 1 returns the engine to "correct stock" configuration, from "messed up by EPAII" configuration. This was not a simple process. Lots of dyno and road time with lots of instrumentation monitoring progress (and setbacks).
Stage 2 will be another matter entirely.

Either way, you can only get so much from the engine without getting into porting etc. and if you start doing that, well, you would have a race car, and they don't drive too well on the street .

fxdsconv2000

Thanks,
I think I'll hold off until Stage 2 is out. I don't have to Smog test my car so the Stage 2 with either no cat or high flow cat is for me

How much would it cost if I buy the Stage 1 now and upgraded to Stage 2 later? Would I have to purchase the whole Stage 2 kit or just upgrade the exsiting Stage 1?

So how long until Stage 2 is out?

Omicron

Good question...

JimW

Hey Maurice or RX8 friend: fxdsconv2000 poses a good question. Is there any insight into stage 2s powerband and driveability? I already proclaimed my desire for stage 2 but, a lot of in town driving occurs at the lower rpm range and can be beneficial for some. Can the stage 2 air/fuel and timing be tuned as such? Since it runs lean at the lower rpm range to begin with, can a bigger fuel pump or injectors be safely utilized in conjunction with timing to acheive this, or is this another animal? perhaps a future mod? Thank's guys.

kristopher_d

When driving at 65mph, grab 3rd to pass. Wind the damned engine out. That's why rotaries are Grrrrrreat!!!

RX-8 friend

I discuss "proprietary" secret discussions below, so promise you will not tell .
We were discussing what could be done for the automatics last night (theoretically of course). Looking at Maurice's dyno that is posted. Problem is the auto motor almost for sure has a different curve, as the intake ports and manifold are different. However, in frustration, Maurice said "just sell your car and buy a manual". Reason is the power starts improving at 5000 RPM and gets fully "nice" at 6000. The auto shuts down at 7500. If we could do an auto and have the same improvement vs RPM as the manual, it would be very frustrating for the driver. The car would just start to "take off" and hit redline!

However, to address your questions, I'm told the stock fuel system has a lot of overhead room (injectors running only around 40% WOT stock) so that shouldn't be a problem. In tests of "what is even possible", using race gas (for safety as they were taking it to the extreme), power in the area of 300ish on a Mustang dyno was seen. Lots of heat was also generated!

Sooo, the quick answer is "yes", you can have more power lower down (using timing for example). Perhaps if we could get control of the intake plubing vanes we could take out some dips as well. In fact, look at the dyno graph, and imagine the "ramp" (where stage 1 starts to have effect) improvement generated by stage 1 continuing (lay a ruler on it), up to 300+. Pretty scary! Stage 2 will be limited by keeping cooling a non-issue and by fuel octane rating. We think the dropoff just before 9000 RPM is the stock system exhaust restriction.

Just some hints.

JimW

Good to hear. So it is possible with better intake tracting in mind!Thanks.

racerdave

I still think an even lower final drive ratio would help a bunch with Stage 1.

This way, the gearing would be a lot better for staying in the 5K + range. As it is, even in second gear (68 mph) you'd be breaking the speed limit on most interstates in the US.

So ratchet the gearing down to make 2nd gear top out and 61 or something, then that would also put you much closer to having 4th gear be the optimal passing gear on the highway.

Just a thought, but I don't know if anyone makes a more extreme final drive ratio for the 8 right now.

DisneyDestroyer

?? am I missing something? In my car I can't get it up to 68 in 2nd, it does top out closer to 61/62.

93rdcurrent

So will racing fuel be necessary with the stage II mod? Or can we use 91 or 92 octane and be alright? And can we use the high-flow/high-temp cat with the stage II mod? Sorry for so many questions.

JimW

Maybe stage 2 could have a switch for alternating between 92 oct and race gas? Similar to what Mopar is doing with the stage 2 SRT-4!

RX-8 friend

Well, I've said it before and I'll say it again, Stage 2 is for racing. On a track. You NEED good fuel, not necessarily race fuel, you need to tune it for your setup and altitude. The cat. should be changed out for a high temp. one, so you don't destroy the stock one. We are worried that if we ship this to just anyone, blown engines could result. There are just too many "street racers" with too little knowledge who blindly install and use this stuff.

I, who have a modified 3rd gen RX-7, know about how easy it is to live on the edge without realizing it.

The current prototype stage 2 uses the same electronics as stage 1, just with more options connected. Multi-maps isn't one of them, unfortunalty. That's why it's not $1000+.

Also, remember that everyone is learning. There may be improvenents to stage 1 in future years (and yes, they will be available as updates for units already purchased). We just need to get more "out there" to hear how well they work under all conditions for now. Stage 1 is safe, pretty much with whatever you do. Stage 2 would not be.

JimW

Stage 2 and the random tech cat with resonator and always 92 oct should be safe then? O.K. I'm ready:D