trevor.racing

ill get right in to it, 1993 rx7 jap, 13b with t04z 550 and 1000 cc ing, 3.5 down pipe with full system, power fc w/datalogit, apexi boost, fuel presser reg, and a high flow pump.
Hear comes the smoking brain cells, we are trying top come up with a safe map to use as a daily driver :S, this is what im thinking
1. oem power fc map
2. disable seq turbo settings
3. retard across the board
4. tune afr
5. slowly add timming following oem curve at 5 % at a time dyno runs after changes
6. set overheat retard to hit harder (water and air temp)
7. boost well be in around 15 to 18 psi pending how everything works
....any input, ideas for timming or fuel?, befor i pull the pin on the hand granade


ok info on me, my name is trevor, i have been in the honda world for to long and now im making the move to fast and lighter things, the 1993 rx7 is my boss car and i have been building it for over 3 years with him, we finaly made the jump to the big one slug last month and now its time to make it work, iv been tuning boosted honda for years so i have an idea what to do but just need some people to hold my hand

cewrx7r1

iTrader: (2)

With 550/1200(bored out 850s) on my GT35R, they were only good for 14psi with duty cycle in the high 80s.

With 550/1000s, no way will it be safe for 15psi.

arghx

iTrader: (3)

I have a T04R (same as T04Z but not ball bearing) and I see 87% injector duty at 18psi with 720/1680 running at 43psi fuel pressure (large street ported engine). 550/1000 is nowhere near enough fuel for that turbo.

trevor.racing

ok guys 850 in prim and 850 in sec, tune the idle and low load with the fc ?, that give 1700 total

arghx

iTrader: (3)

Still not enough fuel for that turbo. You do know that a T04Z can do like 600whp on a piston engine easily?

Also, the 850 side feed injectors don't function so well in the primary position. They can be made to work but there are other injectors that idle better.

trevor.racing

ok, so all 850cc wont be enough to run this turbo full blast but how about like 10 or 13 psi?, and dose anybody have a walk though for doing the 850 in the prim spot?

cewrx7r1

iTrader: (2)

Stock 850s in the primaries is so outdated/old fashion/stupid!

Go with the newer Bosch EV14s sold as IDs.
Get the 750/2000 setup.

trevor.racing

well i went a head and stuffed the 850 in( o ring the bottom), started tuning, idle is total crap 10.5 :S and no matter what i do to the basemap from p1 to p5 and n1 to n4 dose nothing atall :S???.....past that iv used map trace with lm2 and is working nice im at 5500 rpm with 14 psi boost, im at 74 %duty and almost out of map sensor , any ideas guys/galls?

NeoTuri

iTrader: (2)

I gave up trying to idle tune 850cc as primaries. I think there's a minimum amount of fluid they'll pass if they open and its too much. I went back to 550 and bumped the secondaries to 1600. I'll probably run a 750cc/2000cc top feed system soon.

gravytraindg

stock map sensor should be fine to about 16-17psi

Drew

trevor.racing

all good info...people are saying if i set up lag 65 and .04 it well help with tip in

tom94RX-7

iTrader: (5)

You setup manual idle control? Try that and Retard the timing in idle cells to -7 , the more you retard the timing the leaner it will idle. Don't use negative lag it will make you have to use more fuel and higher injector duty cycles. I use 850's with +.04 lag and the idle is decent, not bad at all, Afr about 12.1 to 12.4 and leaner than that when warming up. And I'm at 44 psi base fuel pressure, which made it idle a tad richer but smoother I think.

tom94RX-7

iTrader: (5)

I have to correct myself regarding my post above. I played around with negative lag to get my idle leaner with the 850s primarys, and I figured out this is very easy to do and easy to keep your tune basically the same. Simply inserting a negative lag value and then adding that same amount to every cell in your base map gets your tune basically the same as before, except I had to add a little more in every cell from 4000 rpm to 8000 rpm, and 16000 pim to the bottom row.

I inserted a -.20 lag time correction (it was at 0 before this with the corrected InjPr Lag (ms) vs BatV settings), and then added .20 to every cell in the base map, did some testing and afr's looked the same, except I needed to add an additional .1 in all cells below 16000 pim on the base map and above 4000 rpm. If you don't add to the base map then the afr's are too lean.

This works because when you insert a -.20 lag time correction, the PFC simply subtracts .2 from the on time of the primary injector every time it pulses, this is verified by looking at the InjFrPr values in the monitor window while datalogging and making these changes with datalogit. This reduces the pfc minimum on time of the primary injectors so you get a leaner idle. The default minimum is 2.5 (2.5xx), it lowers to 2.3xx with the -.20 lag time correction value I used.

I wanted to provide this information for anyone in the future reading this thread. I may try more negative lag for a leaner idle, and of course adding the same amount plus a little extra in the base map to make sure the afr are not leaner under boost.