0xenocron

LOL thanks John

That dip after VTEC must have been some sort of exhaust or intake resonance.

BTW, have I ever mentioned how much I LOVE Injector Dynamics injectors?

SR20S13

question, is your graph is that calculated flywheel horsepower or is that wheel horsepower but just says flywheel on the graph?

0mtber

iTrader: (2)

I agree!

Use this to cure the mechanical restriction:



Nice work chris :-)

vtec8200

That is flywheel horsepower, roughly 177whp at a 17% loss.

00Red_SiR

To the best of my knowledge, only an engine dyno measures flywheel HP. If a chassis/hub dyno says flywheel HP on a chart, it would have to be a conversion factor that's being used since they take their readings from the hubs/wheels. Honda's typically lose about 12-15% from the drivetrain. It's an excellent tune and I'm sure the car works great but do people really think for a second that it's putting down an actual 208.6 whp to the ground?

0xenocron

In fact most chassis dynos measure flywheel hp and calculate wheel...how come you can do a pull in 3rd gear or 4th gear and basically they measure the same

This is "comparison mode" which is Dyno Dynamics method of equating to Dynojet numbers...it says flywheel on the graphs (just like dynapack) but every car I have had report to me about going on a local Dynojet the numbers have been within 1-2% as far as I have been told

00Red_SiR

For an inertia dyno (Dynojet):

"Those of you with a knack for physics will realize that the torque produced in first gear at the tire-drum interface will be significantly greater than that produced in fifth gear. Since the rpm of the engine is factored in (by the dyno), the different speeds developed by the different gears are negated - therefore, one can say that the computer reports "engine torque as measured at the wheels."

0xenocron

And the rpm pickup on most dynos is horrible too, which is why you see a ton of dynojet graphs out there without a torque reading. How are they calculating wheel hp if they can't measure torque at the tire-drum interface?

00Red_SiR

DynoJet pickups are pretty flakey for sure. They are still able to calculate wheel HP by back calculating from known values:

(Taken from the Bristol Dyno site)

"The Dynojet calculates horsepower even if there is no torque reading, and it does this in the manner that I am in the process of describing. Those of you that have had your vehicles tested at my shop and have watched the computer screen closely have seen that the computer plots out only the horsepower after each run, and I have to click the mouse a few times to get your torque. It does this because sometimes there is no torque reading, or the torque reading is faulty. This can happen because inductive and optical rpm pickups may not be perfect, and/or your ignition system may make things go a little haywire. If the rpm readings are not perfect, and the computer used the rpm x torque / 5252 formula, the hp reading would be inaccurate.



Work = Force x Distance

Now we get to the good stuff. Calculating the work is pretty simple for the computer. It just figured out the force, and it can easily figure out the distance because it knows the circumference of the drum and how many times it has rotated.



Power = Work / Time

We have an answer. Somewhere the computer factored in the bearing drag, and it throws some constants into those formulas to get the numbers to come out into the right units, but you get the idea."

FkingSUV

first loss in the books.
time to order up some more mods

http://www.youtube.com/watch?v=3j0s-...er_profilepage

00Red_SiR

That race is about right. The RSX you were up against had a decent levels of mods and would have made a good deal more power than you. The only thing that kept you in there was the lighter weight car. What kind of mods are you thinking of next? Cams I would think?

FkingSUV

I've thought about cams but i really like the drive-ability of the stock units. Not to mentioned i averaged 36mpg after the first full tank of gas since the tune.
I figure even with a set of S2Pro1 with cam gears/springs&retainers and a retune i'll still be lacking some power when up against those pesky rsx's.

The plan right now is to hook up a single fogger dry shot utilizing the s300 control. a 50 shot should be plenty to turn around the results of last nights runs.

crazydominicanman

Pro 1's with skunk2 pro series valvetrain

SR20S13

that rsx, if its the same one that chris tuned makes 236whp on the same dyno. So you'd have a decent amount of power to make up but some pro1's maybe a better header if you can afford it? or performer-x intake manifold? but pro1's plus like a 75 wetshot and you'll take them or your 50 dry shot haha

FkingSUV

Thats the one.

Im not sure the gains/cost of the intake manifold and cams (+supporting hardware), are worth it. all my research shows NA application like mine with pro1's (or Tuner2's), net about 10whp on a good day. Although it may make the run closer, it would be hard to expect a win.
And in case its somehow not clear, im still totally happy with the car. The results from that video depict exactly what we figured would be the outcome. I didnt build this expecting to be the fastest car on the street.

SR20S13

run it from a dig though and I bet that it would be pretty darn close, even in my stock bottom end b18c in a eg hatch with shitty 60ft times i was destroying cars out of the hole, then they on the back half i'd get destroyed

00Red_SiR

If, that the case, I would understand you going with like a 75 shot of nitrous. That's exactly how I had my car setup because the motor was enough for me most of the time but I liked having that little extra when I wanted it

FkingSUV

great. thanks for the response. I spent a lot of time reading threw your results while planning this build.
i may do some cams at some point, but the truth is, the car is a riot to drive at this power level. Nitrous should be a simple answer for the few times i take the car out looking for trouble.

FkingSUV

We hope to make it out to english town next Wednesday night if the weather agrees.

Neither cars in the video have made any passes so we're all interested to see what the numbers say.

SR20S13

with a little luck no doubt, you will deff make it into the high 13's with a setup like that. My car making prob. 130/140hp MAYBE would run 14.5@94.88 MPH it still had a stock header/stock p30 intake manifold so you should no doubt get that. I run up at Lebanon valley in upstate NY

FkingSUV

I'd love to see a 100mph trap speed. depending on how ambitious i am that night i may drop the catback at the track.

Zaraki

Wait, so you're at 208whp in your hatch and you couldn't pull that RSX-S???

I have a 93 Si w/ 200whp and I've raced my cousins RSX-S w/ basically the same mods(I/H/E/RBC/Cams/K-Pro) and pulled him every time. Dig, 40 roll, 60 roll, etc.
We even switched cars and he'd beat me when he drove mine.

FlewByU352

WTF chassis are you in where you can run a 14.5 at almost 95MPH with 140HP? Is this like a swiss cheesed CRX or a old Mini? BTW I found the race pathetic, rolls are for bakeries... not racing and doing so on the street clearly where there are other vehicles is just plain dumb.

SR20S13

95 honda civic cx, weighs 2350 i think with me in it, and I really don't know how much HP it was making thats just my guess because when i put a 3 inch exhaust and bisimoto header on it made 160whp stock block c1 with b16 head

FkingSUV

Sounds like your cousin needs a tune?