Just for me to know , how do you guys deal with the normal driving part of the 20b (i say normal , as in just cruising not hauling ***)
for one youre RPM`s tend to stay a bit higher when cruising in 5th gear , and is it just me or does this engine not want to move the car slowly , when ever i try to just move the car real slowly it tends to want to move fast (even when just putting it in gear and not giving some throttle) i hope i am explaining this right
when i try to keep the car moving slow i tend to get a jerking action of the car (might be my clutch though) but it still seems different than the 13B
Anyone care to chime in ??

 

Are you using a springed clutch or solid hub. That may be your starting point.

 

it is springed though , but its a 6 puck copper disk

 

I use a springed round and it engages nicely. Not meant for more than 400hp though. You also must have a light weight fly wheel.

 

Sounds like a tuning/idle issue.

 

No, it sounds like dive train. Do you have a good pressure plate?

 

Yeah , kinda do have a little bit of tunning more to go , i am not shure if i still have that coolant seal issue ,because all of a sudden the car doesn`t blow smoke anymore , that has me baffled i am looking into this first and then going to fine tune it a bit better , i drove the car this weekend and feels great , there is a lot more torque then the 13b , however still breaking in so i am keeping the revs down
doesn`t anybody find it a bit anoying about the high revs when cruising in 5th , at abot 60MPH i am at about 2K RPM ...

 

and yes i do have a good pressure plate , however my idle is a bit rough , i think i am running a bit too rich , whats the usual AFR`s for a ported 3 rotor ?

 

2k at 60 is a good place, wouldnt want it much lower.
if you are using the same trans as the 13b it should be the same.
as for driving the only problem i have is resisting putting my foot into it
matt

 

This sounds like an accel/decel correction issue. If the base map is tuned relatively lean at low rpm I have found that I need to be fairly aggressive with the accel enrichment to stop the car from choking when changing the amount of throttle opening. Don't neglect 500-1500 rpms either since it can make a big difference in how easy it is to engage the clutch smoothly.

 

sounds like a tuning issue

if youre using the same tranny, then your engine speeds are the same. did you recalibrate your tach for the 3 rotor?

as far as afrs, there is no specific number for ratios in vacuum, you kinda just have to tune it to your engine. start with a base map (afrs in the 13s), then take out fuel till it starts to miss a little, then add a little back in. mine runs good at 15.3 in vacuum, and around 13.8 idle, but yours may be way different.

 

yes my tach is corrected , just the sound level gets a bit anoying after a while , .....feels as if i realy need a sixth gear ....i will be playing with my fuel map a bit later this week (i usually dont have time to tinker with the car during the week) i did notice some slight black residue coming out of my exhaust so i am thinking i might be a bit on the rich side there ,
does anyone else feel as if they need a sixth gear or is it just me?

 

my car has a t56 in its future... but theyre still going for almost $2k, plus the custom stuff for the swap, so it might be a while.

 

does that fit without cutting the car ?

 

on the question of needing 6th gear, would a Renisis (RX8) transmission bolt up? Even with minor modifications. I don't know, I'm just giving ideas and thinking out loud, but a turbo2 bellhousing may fit in place of an rx8 bellhousing to use the actual transmission of the rx8. As I said, just thinking out loud. Has it been tried, questioned, or measured? It might be something to think about if it hasn't already been proven unworthy or impossible.

 

i dont think the rx8 tranny is very strong....

 

He's right. A turbo 13b crushes RX8 trannys, I could only imagine what a single turbo 20B would do to it. I dont even think it would last the break in period.

But we're getting off topic lets help felix with with transition problems.

 

yeah its defenetly a tuning issue i think , i just peeked into my fuel maps and its a bit "jumpy" i still have to do a fine tune , i am also looking into the whole timing issue i think my car is a bit too retarded (no pun intended) but my wideband should arrive soon and breaking in will stop , and then the fun starts
Also i`ve looked into this the rx-8 tranny IS way to weak for this application i`ve read somewhere that its the miata tranny ,
Also ive realized its not realy the rpm`s that stay hich (2k@ 60mph) its the engine that is louder (because of the 3rotor ) i might need some getting used to

 

The RX-8 transmission and the Miata 6-speed transmission are basically the same, and not very strong. The Miata 5-speed transmission is like the NA RX-7 transmission, also not strong. You need a T2 or FD transmission for a 3-rotor, or if you want a 6-speed then from a Supra/Vette/etc.

 

but my wideband should arrive soon and breaking in will stop , and then the fun starts

Make sure when you get the wideband that the sensor is NTK sensor and not a Bosch. Nothing against the bosch it just doesn't last to long. I went through 3 in a summer.

 

damn for real ..?...i was planning on one of those AEM units i tuned a supra with one and it was pretty much cool to work with (dont know bout longevity though) does tha AEM use a Bosch ?

 

i like my innovate quite a bit, im pretty sure you can buy it with either sensor.

pat

 

There are differing opinions on which sensor to use and supporting data for both sides. I have had good luck with the Bosch sensors and I like the fact that they're only $35 a pop, because I can replace them at little cost everytime I change the oil. That said, I have used one for over a year.

The best wideband going right now is the Tech Edge. It can be setup to use either sensor type- or the new super accurate Bosch sensor, it has inputs for EGT probes, and a programmable digital display that isn't subject to voltage offset. Pricing is similar to the innovative units, but they are more flexible and the support network is very good. The accuracy is first rate. I got the basically the same readings using it and a motec stand alone unit.

 

I rode in a turbo 20b that had an ACT stage 3 pressure plate & a stock Fd disc. There was no slippage and no jerking.


The Rx8 tranny has an even higher gear ratio than the Fd's. 6th gear is like .80 while the Fd's 5th is in the .75 or something range. The Rx8 tranny would hold up as long as your not putting the power down.

 

Driving the car has becaome a mission since its been raining 4 days straight already , i only drive it on the weekends (work and **** doesnt make it too practical for me ) BUT , i have lifted my rpm limit to 5000 , i found out i have a problem with some bad *** boos creep i have a waste-gate spring of 2.5 psi (dont ask where i got it) anyways at about 5000 rpm the boost spike to about 10psi , its fun and all but anyone knows if you cant controle youre boost you cant controle ****
so i am thinking of adding another runner leading to my wastegate (my current manifold design has 1 runner ) i never didforesee that the 3 rotor would make this much power so i overlooked that area ,
Nonetheless it is still awesome i can spin my tires in 3 gear only using 5000 rpms and 10 psi actually if i am not carefull the car gets sideways in a real hurry ,
Right now its a bit laggy since like i said before i have a 2.5 psi wastegate spring ,my boost controller is not even connected , the coupler the goes from my turbo to intercooler piping has a hole in it ,the discharge port(nipple) on my turbo housing is open (boost leaks from it) and my car is still pig rich (damn wideband hasnt arrived yet )
I know i should get these things fixed but i didnt mind them since i am still breaking it in , as soon as the wideband arrives i will keep you guys posted , and also i will try and fix up an apointment at the local dyno guy here and take some vids
Overall impressions .....hhmm i can spin tires in 3 gear without using all my rpms and just 10 psi (you can actually feel the front end of the car lift up ), i can go uphill in 5th gear at about 40mph , its great so far , but i am taking it slowly though
cant wait for that wideband to arrive to fix up those little things and get that sucka tuned !!