Im the Happiest Person Alive, also DYNO!
 

So this week has been awesome. After changing my spark plugs,oil/oil filter,fuel filter,air filter, and getting a new exhaust i went to the drag strip 1/4 mile again.

last time when i had fuel cuts (stupid fuel filter) i ran a 22.5

this time i ran an 18.4! thats about a stock 1/4 back in the day so im happy! i couldve done better, my launch and shifts wernt the best and my tires suck. hoping for 18 flat next time just with better launching and shifts.

then today i went to a car show/dyno. had the car dyno'd (2 pulls).

but first lil back story. when i bought the car there were a ton of things wrong. but i wanted this car as a project, i wanted to bring it back to life. so i started reconnecting plugs and hoses. i changed all the fluids. i got a new rear end put on. i stripped the interior etc. etc.

the engine before was always choking and dying, never wanted to start, would bog all the time or performance would just suck.

now its amazing. starts easy, pulls hard, no problems. so i feel like ive acomplished something. and ive learned SO much thanks to yall and this site and other owners in groups.

back to the dyno. i know stock there were to have 100/100 on power. so i was hoping to hit close to that (cmon its a 30yo motor, had to loose some power).

it was 105 today, but i wanted to dyno anyway (mobile dynojet). so i told him when to shift (he was happy cuz hed never had the chance to dyno a rotary, just muscle cars) but he said he would have to let off early for the computer so he let off around 4.5k instead of 6k like i was thinking would be better. so that and the heat and 45% humidity really took a toll on all the cars there but im happy to say i made 95hp/94lbft at the wheels!

so i believe if it was cooler and he pulled harder i wouldve made at least 100 at the wheels.

also i won peoples choice! beat a lot of muscle cars.



http://farm3.staticflickr.com/2876/9...67d5545a_c.jpg

now its time to swap on another LSD rear (had to swap on a open diff rear cuz the dude before the dude before me blew the GSL rear, so he got an open diff rear and welded it, then that blew on me). but i bought a gsl rear. then start adding power.

A splendid chapter in an ongoing story. Congrats!

Pretty cool to hear man, congrats!

Congrats on your success - no better feeling than sorting out something complex and making it behave.

So he only ran the engine to 4500 RPM?

yeah he shifted at 4k in 2nd and 3rd then did the peak run in 4th (as do most dynos if not all) only up to about 4.5k (was watching the screen). i but hey im still happy with 95! especially in 105 heat.

What are your mods?

Good to see you sorted it all out.

I've always been afraid to dyno mine - - too many horror stories about perfectly-good engines being grenaded on the dyno, pushing for higher numbers.

I don't know...an NA revved to redline a couple of times for a dyno tune should be fine. Piston engines...they're prone to dropping valves or spinning bearings on the dyno when taken on a couple of trips too many to redline. I should know...spun a bearing the day at the track a day after a dyno session...I'm sure the extended dyno time didn't help things. Turbo rotaries may be more susceptible to grenading due to heat, but if you're dyno tuning it, the idea is that you get off the engine when things get lean and make corrections.

fm

So you got 95 whp on this thing? That's pretty good...that's about 10 bhp over what a fresh 12a should have stock. I, too, would like to know what mods you have.

fm

Good work looks fun

Mods at time of dyno:

STP air filter
valvolene 10w40 conv. oil
k&n gold oil filter
stock header, straight pipe to straight through muffler, no cat
2ndaries 1/2 spring cut on vacuum
rear hatch stripped
shitty dry rotted tires (LOL)


nothing special. so im glad to make it to stock hp at the wheels and a lil over the crank.
like i said, the car used to run terrible. now its quicker than ever.

i did delete my air pump after this event. car seems muchhhh better without it. :)

soon ill be deleting my a/c and doing duel pulley

(yes thats right, no a/c in texas when yesterday it was 108!)

ive been to several mobile dyno sessions (other than this 1st one on my car)

they most the time dont push it to redline. they stop way before.

now on a in shop dyno i have no clue what they do. im just glad this wasnt a mustang dyno or i was afraid my car was gonna show like 40hp...gotta love the heartbreaker dynos.

so i went back to the strip today. i took my air pump out. took my ceiling, storage bins, carpets out and all the pink fluff underneath.

i was hoping this...with my "bad" shifts and crappy tires would still run me an 18 flat in the 1/4.

well....i didnt run an 18...

I RAN A 17.4!!! and that was with spin and bad shifts (im still learning)

im going to take the door panels off and then dry ice the tar tomorrow and then take the a/c out and run a duel pulley and well see if i can run a 17 flat next week. also going to replace my clutch hydraulics.

i think ill do realllyyy good once i get some grippier tires.

not bad for a 30yo 1.1L

Good show!

With the mods in my signature I dynoed at 134 whp 124 torque. That was before the RB SP
exhaust and the ignition upgrade.

Sound like your on the right track.

Nice...that's what I was hoping with a similar setup.

Milkstout, not to rain on your parade, but there's no way that losing maybe 40-50 lbs at best would have dropped your time by one whole second. The best that this kind of weight loss would get you in the 1/4 is less than 1/10 of a second. I think you're just getting used to the car and driving it better. Either way, good show!

fm

i still spun and my shifts were slightly better so maybe so. im still taking tar off. so itll be fully stripped in a day or 2. also still need to take the a/c out.

if thats the case. once i get new tires and clutch hydraulics i should be running alot better. my "speed" shifting has gotten better thanks to the strip

Time for some logo stickers - - 5hp each!

The first time I ran my Civic at the drag strip, I ran a 13.8 @104 mph on street tires and full interior (including a baby seat). I had a 2.23-second 60' time. The next time out, switching from street tires to slicks, I improved my times to 13.4 @ 102 mph... my shift points were too low. I had a 1.9-second 60' time. Same specs, same interior. I'm reasonably sure I could have dipped into the 12s if I had revved the car out to where it should have been...stupid ECU config error on my part.

I stripped the car of 350 lbs, kept the same power (actually was a little down on power), but adjusted the ECU and got a 13.2 first time. My times got worse after that because the engine was starting to go... started hearing rod knock and had to stop the party. I only managed a 2.1-second 60' time that run, so I would have been well into the 12s if the car would have held up.

This is to illustrate that the biggest difference in my times was due to traction. I dropped my time by almost half a second by just swapping out to slicks. The 350 lbs I shed would have been good for about .3 secs.

BTW, Road and Track did an article on the RX-7 some time ago (don't remember the year) and it showed the 1/4 mile time for the '79 GS as 17.0, the '83' GS as 17.1 (a little heavier car), and the '84 GSL-SE at 16.4. Mind you, this is a car with new tires, multiple runs on ideal track conditions, and with an experienced driver at the helm. So with a stock 12A car almost dipping into the 16s, a car with slicks (or drag radials) should easily get into the 16s. Just be careful with slicks...I know on my Civic, if I got wheel hop, I could say goodbye to my axles. I'm not sure how well our cars absorb the shock of a launch on slicks.

fm

http://img812.imageshack.us/img812/702/3zka.jpg

nice job!

There is often no point in pushing to redline. Once you go over the top of the curve in both HP and Torque it isn't going to go back up so you might as well stop. I suppose knowing what it does up to redline could help you choose shift points if that was your goal.

However in this case I think I would have insisted in going to at least 6500 rpm because the HP/Torque peak is supposed to be up there somewhere.

Now I am going to have to go look at some of the dyno plots.

Max bhp is achieved at 6000 rpm on stock 12a and 13b engines (84-85-spec 13b that is). Max torque is at 4000 for the 12a and at 2750 on the 13b. If the car has mods, such as carb, header, or any sort of porting, that power bad will shift upwards.

Milkstout, by killing the dyno at 4000 rpm, you're not seeing the true power you're making. You should run it to at least 6000rpm. With mods, a little higher, just to see where your power actually peaks. Also, you're not doing yourself any favors by dynoing the car in 85-degree weather. The heat will kill your power. I saw a 15 whp difference on the same setup on an 85-degree day and a 55-degree day.

At what rpm are you shifting? Remember that even though you may not be making more power above 6000 rpm, you want to go past that so your shifts drop you into the sweet spot of your power band. If you shift too early, you'll be struggling to get the car back into its power band and lose valuable time.

fm



Whe

Damn phone...


Power BAND, not power bad. I meant 95, not 85-degree days.

fm

Dynos should have an SAE correction factor which should keep things pretty close, but you will always see higher numbers on cooler days.

My stock sans catalytic converter 12A 5 speed car would do a consistent 16.0. No belt on the air pump, no A/C. I was pretty happy with it.