i have a bunch of maps in my pc for single, stock twins, etc but nothing that looks like what i need now.

I need a map for 4x850cc, on stock twins and a streetport. I know this is a long shot but if someone has something close to that and want to share, i'd appreciate. I have some maps i can give in exchange if you want to see some different things, most of them are tuned by steve kan.

thanks

 

Take a map for same port and single turbo, and you could add back more timing
(1-3 degrees) above 5000rpm.

Logically think how the two flow differently form mid to high rpms. And include turbo back presure.

 

yeah good advice but let say i was more worried about the 4 850cc. Plus all, the single maps i have are for 1600cc which completly changes the dynamic of the A/F ratio.

I have yet to see how it reacts with the 4 850cc, i am having a problem with the first one i just did, seems like it flooded for no reason and now i am unable to restart it. So i thought i would try a different map. Seems like it is injecting too much fuel on startup even though i lowered a little bit the inj crank time.

We started the car a couple of times and it worked pretty good then one day, it juts made some back fire and never started again. Try the oil trick with the cleaning of the housing and it still won't start. Were are going to try new plugs even though those only have like 30 minutes of life...

 

Almost everyone knows that 850 primaries are not the way to go unless you have too. They are a hard to idle tune unless using negative lag. The PFC has a minimum idle inj ms time which the only way around is lag.

This has been discussed for many many years!

 

just wanted to give a quick feedback of what happened, we removed the plugs again and installed some new one with some oil in the chamber, car started right away, in fact, never seen an rx-7 start so quick. I have also changed the inj crank time to some that i have found here on the forum (lower) and it starts real quick. I suppose we had one or two plugs that were not good in the previous batch.

Chuck, your comment about having trouble with idle with 850 primaries really scared me but this car, untuned for now, has a perfect idle, i have seen many cars tuned with much worst idle than that one. It just stabilizes so quick, man this car runs good. Now the break-in can start.

thanks for your help

 

The simple and proven fact is that 850 primaries should not be used on a street car if you want to be able to easily tune idle and low cruise.

Use 550/1600 which can handle a lot of power. For a race car where idle is not important and you are not on the street in stop and go driving, then they are OK.

850 primaries were needed in ancient RX7 history before enlarged secondaries were available for RC Eng. or Bosch 1600 were available.

 

wouldn't 1600 be a little overkill for stock twins under 15 psi?

i must admit the bored 1300 would be the best compromise but i am kind of afraid to install these on people's car since so many people have had problem with those.

Would you trust them? For a single turbo i install 1600 no question but i am kind of confused when it comes out to twins that need just a little extra fuel. This is why i thought 850 primaries would do the job since they are oem injectors with their known reliability. I guess these are the last i am going to install, i'll keep my search for the perfect setup...

 

I ran 550/1200 on my non-seq twins at 15psi boost below 85% duty cycle.
The 1200 were 850s enlarged by RC Eng. I did not go 1300 for the same reason of some published problems. Rewiring the fuel pump also reduces duty cycle.

 

yeah i always rewire the fuel pump, taking no chances.

so you think that boring the injectors to 1200 will be more reliable than going to 1300? I thought it was the process that was the problem, not the size...

I admit i have no experience with those and i beleive i will try to do a little more research.

thanks.

 

i was running 1300 primaries and 850 secondaries (don't ask) a few days ago by accident and it was drivable. Not sure what you guys are talking about 850 primaries not being drivable lol.

thewird

 

Driveably but harder to tune and not normally needed. So why do something that requires more work and is not needed?

"If it ain't broke, don't fix it!"

 

Understood. My setup is 550/1300 anyway just found it strange when I was running 1300 primaries hehe.

thewird

 

Trust me the 850 Primarys really sux, I cant get any leaner than 12.2 AFR @ 1500 rpm idle, that is even with 0 for the amount of fuel to inject. You just cant turn it down

 

I have 98 octane fuel over here.. Does anyone have some fuel and ignition maps I can use until I get my full exhaust and then proper tune.
Currently completely stock series 8 (stock twins, stock exhaust etc.)
Runs very rich I believe as the octane is much lower than Japan's 106?

 

Check what they mean by Octane in japan weather its AKI, RON or some average

 

If you have a datalogit, go to the Settings 5 tab and change the Injectors settings. I've attached a pic of how mine are set (you'll have to adjust for your 1600s) and I'm able to get idle AFR in the 16s.

Having said that, I will eventually go to 1300s because I prefer to run the airpump and with the 4x850s I get annoying backfiring below 3k RPM that I've had little success tuning out.

-Scott

 

^How'd you come up with 80.0 on the pulse timing??

FWIW if you use different settings than what the manual calls out you are definately going to need to redo the whole fuel map.

 

I don't remember why I didn't go with the standard 64.7, but I know I didn't come up with it. I'm sure I found it somewhere on this forum.
You're absolutely right. I changed the injector settings before doing any tuning.

-Scott

 

^Wish I would have. Now I just deal with a rich idle because I don't feel like retuning the whole map.