ddub

Right, so..... I got an S-AFC, had it installed and then dyno tuned it, and now I have some questions and concerns.

First, my S-AFC is weird, cuz in Low Throttle settings everything is fine, but in High Throttle settings adding fuel (+) actually subtracts fuel and substracting (-) adds, so its opposite. But it's all hooked up correctly, the installer and I checked the connections on the ECU again to make sure and everything was hooked up right. Plus Low Throttle works the way its supposed to, any ideas why its like that? It isnt that big of a deal since I know just to do the opposite, but I was wondering why it'd be like that.

Anyways, to the concerns.....After tuning, my best run was 119 rwhp 115 ft/lbs... WTF is wrong with my car? That is not very good at all. I mean, I have a K&N cone filter, RB Header, Bonez High-Flow cat and dual mufflers that are not restrictive at all with 2.5" piping all the way through, and magnecore 10mm plug wires. Shouldn't I be higher than this? Is something wrong here? I'm pretty sure there is.

Also, just trying to make sure, for setting the car type in the rx7 you do 4cyl, right? Or is that wrong?


Last question. So I was looking at RarerestRX's dyno readings from when he tuned his GTU, and I noticed on his printout it says "3rd GEAR WOT BASELINE" at the bottom... here's the pic from his post



So my question is, are you supposed to dyno in 3rd gear? i thought it was 4th. Cuz, 4th gear is a perfect 1:1 so its not multiplying the torque at all, and 3rd gear is 1.366:1, so thats not your real power, am i right? Or am i confused about something here? So, if that was true, then if i had ran it in 3rd gear instead of 4th i would've essentially gotten 162.554 rwhp and 157.09 ft/lbs (multiplying hp and torque by 1.366) right?

I'm confused and worried... Someone tell me I should've dyno'd in 3rd or something, I'd rather not have problems with my car......

Rpeck

What kind of dyno was it? All the dyno's I have ever been on .. you plug in the gear ratio's of the gear you dyno in and rear end ratio's. then the computer does the caculations for you. I have dyno'd in both 3rd, and 4th gear. i prefer 3rd. shorter pull with the heat buildup and such, and safer. 4th gear at redline your tires are spinning awfully damn fast.


-Robert

ddub

I'm not sure, it says WinPEP DYNOJET on the printout

I dont recall him putting in any gear ratios, rear end ratios or the gear... But it's not like this place doesnt know how to use their dyno, they are a well known business and have lots of ppl coming in to do dyno tuning


I'm mainly concerned about wtf is wrong with my car

Rpeck

Well if they did not have the rear end and gear ratio's set right, then you will not get accurate results .. therfore nothing might be wrong with your car.

ddub

I dont think they would've set it up incorrectly, they know what they're doing and they dyno tune cars all the time....

So, as I'm trying to find out, anyone have an idea wtf is wrong with my car and why it's being such a piece of **** to me...... Sorry but i'm really upset

KiyoKix

That's a pretty dyno sheet...nice and smooth.

ddub

Thats not mine... Thats RarestRX's

andrew lohaus

your aux port are working right?

ddub

no clue, but i was talking to someone on aim trying to help me that suggested that too...

i guess ill do the test thats on aaron cakes site to see if they are or not. hopefully thats the problem and its an easy fix

13bpower

Can you post a pic of your dyno sheet. It the aux ports are not working it should be obvious in the hp curve.

poor college student

one fo the reasons they don't do many dyno pulls in 4th gear (according to Mr. Dragoun @ 7s only racing) is that if anything happens... the wheels are spinning at 120+mph at the top of the 4th gear pull... that's a LOT of damage if anything happens....

deevious

I don't think the damage will be that different between 90mph and 120mph. It'll be a big mess in both cases.
It all comes down to proper strapping and weighting. And a well maintained dyno off course.
With my previous car I've done dyno pulls in excess of 140mph (and that was a diesel!!!) :-D

wozzoom

Where do you have the low/high crossover point set on the AFC??? You have an 88 FC which means your TPS is a single plunger. This is not an ideal situation because the S4 TPS only reads the first 20-25% of the throttle position. After you put your foot down beyond ~25%, the AFC will go onto the high map... Basically what I'm saying is that you don't even have to worry about tuning the low map. If you don't believe me, take your car out and watch the Throttle Possition % on the AFC. Try and drive the car without getting into the high map.

Next thing: You really need to know the status of your car before going on the dyno. 6-Ports are a big deal. Your low HP nuumbers are about right for a car with stuck 6-ports. Make sure they are working properly. Since you've equiped your car with a header and highflow exhaust, you may not have enough back pressure to open the 6-ports. Verrify they are working NOW.

Other things to think about:
How many miles are on the engine?
What are the compression numbers?
How old were the spark plugs?

wozzoom

Scan your dyno graph. I'd really like to see it.

ddub

I dont have a scanner to scan the graph, sorry.

There's 148k on the car, about 20-30 since the engine was rebuilt, though. Compression I dont know cuz ive never done a test. Spark plugs were replaced less than a month ago


And yes i know about the lo and hi throttle, we didnt even touch the lo-throttle, only hi. Also, what %'s should i put in for when lo and hi kick in? I know 10 for lo and 50 for hi is default, but someone else told me to do 40 and 60.


Would a header, high flow cat and less restrictive mufflers really cause the aux ports not to open? if so then why do they even sell the header and high flow cat for the n/a? that doesnt make sense to me that if it would hinder the performance rather than increase it ppl would continue to buy them.


And yes i am going to check my aux ports today after i get home from school to see if they are working.

wozzoom

Like I mentioned with the S4 TPS. You're never going to see 40 and 60% throttle. Set it at LOW=98 and HIGH=99%.


Yes it's possible. This has been a problem with S4 NA's ever since people started modding them. The pressure to open the 6-ports comes from the exhuast backpresure. If you remove to much restriction, then the 6-ports fail to open all the way. (Or they open late)

As long as you still have a catalytic converter on the car, you should have enough pressure.

I'd start with trouble shooting the actuators. Make sure that you can operate them by hand. Pull the vac hose off and blow into it...You should be able to operate the sleeves by blowing.

Rotary Racer

Lets see if I can answer some of your questions. BTW I am the one who tuned RarestRX's car.

Like Wozzoom asked where do you have the low/hi set at? This could be an S4 TPS possible issue but I can’t be sure at this time. Have you tried to call Apexi and see what they say? Apexi are a bunch of good guys and they know their product give them a jingle.

I hate to say it but the dyno is a harsh B***h. Kevin's first ever dyno pull we only got 140 at the wheels. So with that in mind stock is 160hp at the crank after the approx. 15% drivetran loss puts down 136hp at the wheels. Then add the modifications he had at the time brought up that # to 140. Take your car for example stock 146hp at the crank, approx. 15% drivetran loss brings you to 124 hp at the wheels. With the mods you have I would expect to see 128-135 depending on how you tune the S-AFC. So yes your #'s look low. I would be researching why your car is not producing the #'s. Compression test, checking to see if your 6th ports are working (you could try manually opining them) clean fuel system and a clean ignition system. BTW what was your fist pull with out the modifications to the S-AFC? Lets see the pic of your dyno pulls. Do they have the A/F graph on them? I assume you used a wideband to tune properly.

BTW it's a GTUs not a GTU .

Yes you are correct the more accurate gear to dyno in is 4th. But 3rd is mostly used for a couple reasons. 1 some dyno's only read up to a certain MPH and using 4th would bring the MPH to high for the CPU to read. 2 dynoing in 4th gear takes a longer time thus putting more stress and heat on the motor, 3rd gear is quick and the loss is not that bad.

Other than the weird (+) is neg and (-) is positive thing sounds like the #'s are correct and you have some demons to look into. PM me if you have any other questions.

- Dana *Throws up fist in the air* "Damn you dyno, DAMN YOU TO HELL!!!"

SDrotary-FC

you can always zip tie you ports open when at the dyno.

Amur_

Just have two cents to throw in about checking the aux ports.


Just b/c the actuators turn, doesn't mean they're turning the sleeves.

My ports have always appeared to be working perfectly. I say appeared b/c a few weeks ago I ripped them out and pulled the sleeves to make sure that everything was clean in there.

What I found was that the arms that go from the actuators to the sleeves had deflected - the arms had been twisting in empty space. I've been driving with that motor for 3 years with zero function from the aux ports and never knew it.

Everything's connected properly now, but I have to repair an rpm switch before I'll finally find out what driving with those ports working is really like. Looking forward to it.

wozzoom

You could do this BUT the problem is still there when you get off the dyno. Plus, the dyno will tell you what RPM is optimum for opening of the ports.

I operate my 6-ports with an RPM switch. My first time on the dyno, I set the switch for 3800 RPM. After a couple of runs, we adjusted them to open at 4500 RPM because they were opening too early and I was actually loosing power from 3800 to 4500. I would have never known this if I just wired them open...

Fix the problem. Don't just create another.

wozzoom

Wow! 3 years? Were the sleeves stuck open or closed? Or where they just rotating around randomly? I've never heard of the arms becoming deflected like that before on there own. Maybe the previous owner of the car didn't install the lower intake proplery?

ddub

Thanks for the help and suggestions everyone... I'm actually going to be taking my car into a local shop "Bothell Imports" thats been suggested by NW people as a very reputable rotary shop. They have a guy there, Steve Hayes, that is their mazda technition that works on rx7s all the time. I scheduled a 1 hr diagnostic testing for him to look and see whats wrong. Supposedly in an hr he can let me know everything that's wrong with my car and how much it would cost to fix it or how to fix it. Hopefully they will get everything worked out

I am still going to check the aux ports tonight, though, and see if I cant find some of the problems myself before I take it in.

Amur_

They were sitting closed. Fair amount of goop on both. Dunno if they ever actually turned on their own - I can't see through steel.

My mechanic was also suprised when I told him about it on the phone. But then, a lot of things about my car surprise him - there's usually something funky happening with it that's he never heard of happening on any other 7.

I'd assume that they were deflected b/c of a previous install - whenever it happened, it was b4 I got the motor. The thing is, I had to bend the forks pretty far to get them to fit onto the connecting rods in the sleeves. I didn't like that, but it was the only way to make it work. Next time I'm at my mechanic's shop I'm gonna have a look at one of the blown 13Bs they have there and see what things normally look like.

RXSevenSymphonies

iTrader: (2)

We did the grease on the actuator rods test, they definitely did not move. Tried to move it with our hand too.. not working out... so what should we do, try to wire em open?

jacobcartmill

iTrader: (6)

take the LIM off, take the sleeves out and clean them. take the actuators off and clean them. make sure the sleeves are shiny clean (or as clean as you can get them) and make sure the actuators open when you blow into the air tube.

after all the cleaning is done put everything back together and make SURE your actuators have pressure going to them (make sure they have a REAL pressure source, use the air pump if necessary)