yy4u

Well the results were a little dissapointing but anyway, here's the deal.

I don't have any sort of boost controller and to control boost i have to climb under the car and adjust the wastegate screw manually.

THe outside temps were in the 90's and they only had one pretty small fan blowing on the car.

WEll i showed up with the car running about 11psi, so i dyno at 11 psi (0.79 bar) and my A/F ratios are actually quite good. staying between 11 and 11.6 all the way from about 4500rpm to 7000 or so and max HP was 317

I turned the boost up to about 13 psi (0.91bar) and hit 346 rwhp at about 6800 rpm or so, with some break up at high rpms

I turned the boost up again and had it set at 20+psi somehow, don't ask me why. And after a couple of runs of it leaning out rapidly at high rpms when the boost passed 17psi (the threshold for the stock map sensor) and so those runs were cut a little short, before figuring out what i had done when i saw the PFC showing 17psi and the mechanical boost gauge showing 20psi.

I finally got the boost back down to where it was peaking at about 16 psi (1.08bar) and did few more runs.

Top run was 404 rwhp, with a/f's in the 11's and leaning out to around 12.5 at the top end. Last run of the day was 393rwhp with slightly safer a/f's in the higher rpm's

What bothered me a lot was that my boost would get to 10psi very quickly and hesitate/hold there for 1000 rpms or so, before starting to climb again and would climb all the way up to 15-17psi. One of the other forum members thought this may be due to the fact that i dont' have an electronic boost controller and that one would help dramatically. any ideas??


In any case, i was slightly dissappointed in the power produced, i thought it would be a little higher than that, but i suppose being as hot as it was didn't help things. My intake temps stayed in the 50-55 degree C range

I'll post the graphs when i get access to a scanner.

I did most of the fuel tuning with the PIM voltages on the Power FC, however i tried to go the injector maps and tuen from there but at the lower right of the map at high boost and high rpm the cells were maxed out at (1.496) and i really needed them to be a little higher for the higher boost to prevent it from leaning out like it did. It seemed no matter what i did with the PIM's it would still lean out at high rpms. Could it be my fuel pump? I know my injectors can handle the flow, but not sure if the pump can keep up. If the pump couldn't keep up would the PFC show 100% injector duty

I know the stock map sensor is worthless above 1.2 bar, but is it inaccurate as it approaches that peak number to the point that it won't read enough boost and therefore the power FC wouldn't supply enough fuel??

All the runs were made on 93 octance pump gas

Any ideas, thoughts, or suggestions are greatly appreciated!!

-Rob

yy4u

BTW, i do have an aftermarket fuel pump. Nippondenso i believe, but it was on there when i bought the car and i haven't investigated thoroughly. Just noticed it wasn't in my sig and figured many people would say that it was the problem....

anyway, tell me what you guys think

skunks

break up in the higher rpms is due to your sparkplugs or ignition system, are you planning to get ignition upgrades in the future? I think this would help you a lot.

yy4u

i have the hks iridium plugs and magnecor wires but no twin power or anything of the sort.

KraftDinner

403 rwhp and 393 rwhp with 16psi boost isn't too bad in my opinion.

twint78

aight first off yy4u im there with u man
dont worry about that power
when i dynoed my t78 at 14-15lbs it was through the wastegate.i have a boost controller now.
well i wasnt getting full boost til 6000 rpms
so at 6500 and a couple runs we gave up.it dynoed at 307rwhp.
ur ignition system is way strong enuff.that is not ur problem
u need a manual boost controller
see the wastegate takes forever to get the boost up there,so hp is lower.when u add the boost controller u will have full boost by 4500 rpms, i did.therefore getting 400rwhp range areaat 15lbs.
my car was also unfine tuned when i made these passes.
who programmed ur pfc?xs?
this is also what i found out.
xs has to tune ur computer for 1300cc injector t04s kit.its the only base maps they have.and i have a t78 with 1600's.
also the reason u r getting real lean in the upper rpms is cuz a t04s is made for mid range power.that means xs engineering put a bunch of fuel in the lower to good mid rpm range.as where a t78 makes high rpm power where xs doesnt put extra fuel.
we found this out from a couple reasons.
but one was that we added fuel in the top end and we got 17 extra rwhp.of just messing with one little part.we didnt even tune the whole map.
best thing to do is call next week to rotorsports racing next week in kannapolis, nc and ask for brian.he is getting a datalogit,plus he has many t78 fuel fine tuned
maps.hope this helps.

yy4u

SR tuned the PFC, and yes i need to find someone with a dataloggit to do some more tuning. Thanks for the help !!

RETed

I agree - those are pretty respectable numbers from your T78 for that boost level.



-Ted

Cheuk in Seoul

I agree, those are acceptable numbers for a T78 at 16 psi.... remember that thing doesn't get into its sweet range until the boost is up around 20 psi.

94touring

Thats not too bad, anywhere around 400rwhp on the street is pretty good. I will recomend the twin power igniton amp, I know it helped me run much smoother in the higher rpms and i'm sure I picked up some power too.

yy4u

twin t78, what kind of manual boost controller do you have. Will manual controller be as effective as an electronic one.

vosko

iTrader: (4)

you can try www.boostvalve.com

twint78

i am using a t78.manual and electronic.is like oranges and apples.a shitty manual can cause boost spike,but so can an electronic.but a good manual boost controller just far supercedes a an electronic controller.no wiring, no hassle, no fuzzy logic, no low or high setting, no glitches .just turn it up and go, or turn it down.but i use a dna manual.its about 100 bucks and its all u need.u can find it at the suprastore.com

surfpac

You can even make your own manual boost controller. The pressure relief valve is the way to go and not the bleed type valves. I've made a couple of them and my friend is using one on his Turbo II and it works well. Quick spool up (due to wastegate being completely shut before desired pressure is reached), accurate, no boost spikes, no boost creep, simple to adjust, cheap to make (or buy).
DIY boost controller http://pages.cthome.net/gus/mike.html
or you can get from Ebay or these other guys
http://www.dawesdevices.com/boost.html
www.boostvalve.com

surfpac

You can even put 2 of these together with a solenoid valve and make a dual stage controller.

Mr rx-7 tt

iTrader: (5)

Quote "I turned the boost up again and had it set at 20+psi somehow, don't ask me why. And after a couple of runs of it leaning out rapidly at high rpms when the boost passed 17psi"......

You need a more powerful fuel pump...That one doesn't flow enough.

surfpac

You can even make a single or dual stage with boost rate control, which allows you to set how quickly boost comes on, as well as how high it goes. Just think outside the box.

surfpac

Here's the link to the single stage with boost rate control.
http://www.autospeed.com/A_0685/page1.html
Just make two of these and a solenoid valve to make a dual stage. Now that should be enough flexibility.

sexxy7

I certianly didn't mean to turn the boost up that high, but its very hard to tell how far its been turned up when i just have to guess how much to turn that damn wastegate screw. I didn't realize i had turned it up too much until i finally looked over at the mechanical boost gauge and realized it was significantly higher than the boost i was looking at on the Power FC. I know my current settup isn't capable of 20psi but i was hoping it could handle 17psi.

Is the fuel pump i have now not capable of even 17 psi? I'd hate to replace the fuel pump and still have the same problem of it leaning out up top. Is that the most probable culprit.

THanks
-Rob

yy4u

sorry, a friend had logged in on my computer.

vosko

iTrader: (4)

i'm gonna see how the blitz sbc-id works controlling boost on a T78 if not i have a greddy TVVC sitting in my room

Heath

iTrader: (11)

Please let us know how the Blitz works when you install it.

jtmiller02

Were you the FD @ strip fest yesterday in greeleyville? I used to check out all the import forums pretty often and hadn't been on here in a long time...but thought that sounded like the car i saw yesterday. I was the guy on the blue banchee that stopped and talked to you for a few mins. I'll check out our tapes and see if i have any video of your runs, if so i can try to get that to you, I know we have about an hour and a half of bike footage. Mostly stunt stuff not much racing... I was trying to get some good stuff to use in some new videos we're making, take it easy Jon

sexxy7

hey Jon, what's up!? This is the chic that was with him

jtmiller02

hey, sorry i kinda took off in a hurry and didn't really even say goodbye to you guys, the guys were getting started with the constests out on the track and i needed to hurry up and get down there to get some good video. I duno how late yall stayed but there was some pretty sweet stunts and stuff later on in the evening. It was good to see some other people around who are into real perf. cars, [not hondas and mustangs] If you're looking to get up with more RX-7 owners from SC, I'll talk to my friends and see who all has them still, you can also check out http://www.hightach.com , which is the website for the racing club that i helped start a few years back, at one time we had almost 10 3rd gens. in SC that were members. again it was nice meeting yall, i'm very sorry but i'm terrible with names, but remind me again and i'll do my best --Jon