Jump to content
SAU Community

Recommended Posts

Hi all,

I just had my car tuned at Hills (awesome tuner btw - thanks to all who recommended them) and got 177rwkw, which I'm damn pleased with. I'd like to know what my torque is though, but the car was dyno'd in 3rd and is giving me insane numbers. I think I saw a thread on this a while back but noone actually said how you can convert the number to the real torque.

Anyway, you can get my dyno sheet at www.ozemail.com.au/~caddies

Anyone know?

I'm sure it's got something to do with the 1.3:1 gearing on 3rd, but dividing by 1.3 certainly isn't giving me correct numbers.

Cheers,

Michael

Link to comment
https://www.sau.com.au/forums/topic/6907-torque-multiplier/
Share on other sites

Yeah I'm still interested in figuring out the flywheel torque too :(

Out of interest what mods have you got and what boost are you running? My intercooler plumbing is killing my power, I'm going to get that sorted early next year. Every mechanic that sees the way the pipes are hooked up with right-angle bends gives me a worse reaction and a bigger speech on how crap it is. Mark's was the worst :D

Link to comment
https://www.sau.com.au/forums/topic/6907-torque-multiplier/#findComment-104004
Share on other sites

OK I think I have nailed it. I think the answer to your original question is that your dyno is showing 2.33 times the flywheel torque after losses(I will explain what I mean by that later). I don't know why it's 2.33 but I will explain how I got there.

Firstly the I have used ratios from here which I think are correct. My car redlines at about 100km/h in second so I know the first one I had was wrong. So using this your max power at 129km/h is 6157 engine RPM, which seems fair. At this speed your wheels are doing 1084 RPM. Now given that kw=NmxRPM/9551, that means with 177kW the torque at the wheels is 1559.7Nm at the wheels. Thats impresive.

So I think what the dyno operators do when they set it to display torque at the wheels is reflect this back to the flywheel. eg. Torque=Nm@wheels/(Gear Ratio X Final Ratio). That would give you 274.56Nm at your peak power (you get the same figure if

you put 177 and 6157 into the Nm=kwx9551/RPM formula where RPM is engine RPM). This again seems fair because the torque at peak power at the fly with stock 184kw@6400RPM is 274.59Nm. So you are making about the same torque at the wheels as a stocker at the fly, but slightly less power at the wheels than stock fly power due to the fact your peak is at slightly less RPM.

Here is the spreadsheet with the right gearing. You can put in you tyre stuff, different speeds and power to find torque.

Link to comment
https://www.sau.com.au/forums/topic/6907-torque-multiplier/#findComment-104406
Share on other sites

OK, here's a full list of my performance mods -

* HKS Type S FMIC

* HKS Cam Slide Pulley on the exhaust camshaft - 2 degress retarded

* Trust Airinx Pod Filter

* 3" front/dump combo pipe with a separate wastegate line, all HPC coated.

* Fujitsubo twin 3.5" catback exhaust

* Apexi Super AFC

* GFB Bleed valve (14psi)

* GFB Hybrid BOV (not really a performance mod, but it could affect how the car runs I suppose)

I think that's it.

Cheers,

Michael

Link to comment
https://www.sau.com.au/forums/topic/6907-torque-multiplier/#findComment-104454
Share on other sites

b2barker,

That all makes a lot of sense. I am glad we finally got this all sorted out. I might copy and edit my dynosheet's Torque scale on the left to reflect what it should be. After all, even if I get it slightly wrong, I'll at least be closer to what it should be.

Cheers,

Michael

Link to comment
https://www.sau.com.au/forums/topic/6907-torque-multiplier/#findComment-104457
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Let's be honest, most of the people designing parts like the above, aren't engineers. Sometimes they come from disciplines that gives them more qualitative feel for design than quantitive, however, plenty of them have just picked up a license to Fusion and started making things. And that's the honest part about the majority of these guys making parts like that, they don't have huge R&D teams and heaps of time or experience working out the numbers on it. Shit, most smaller teams that do have real engineers still roll with "yeah, it should be okay, and does the job, let's make them and just see"...   The smaller guys like KiwiCNC, aren't the likes of Bosch etc with proper engineering procedures, and oversights, and sign off. As such, it's why they can produce a product to market a lot quicker, but it always comes back to, question it all.   I'm still not a fan of that bolt on piece. Why not just machine it all in one go? With the right design it's possible. The only reason I can see is if they want different heights/length for the tie rod to bolt to. And if they have the cncs themselves,they can easily offer that exact feature, and just machine it all in one go. 
    • The roof is wrapped
    • This is how I last did this when I had a master cylinder fail and introduce air. Bleed before first stage, go oh shit through first stage, bleed at end of first stage, go oh shit through second stage, bleed at end of second stage, go oh shit through third stage, bleed at end of third stage, go oh shit through fourth stage, bleed at lunch, go oh shit through fifth stage, bleed at end of fifth stage, go oh shit through sixth stage....you get the idea. It did come good in the end. My Topdon scan tool can bleed the HY51 and V37, but it doesn't have a consult connector and I don't have an R34 to check that on. I think finding a tool in an Australian workshop other than Nissan that can bleed an R34 will be like rocking horse poo. No way will a generic ODB tool do it.
    • Hmm. Perhaps not the same engineers. The OE Nissan engineers did not forsee a future with spacers pushing the tie rod force application further away from the steering arm and creating that torque. The failures are happening since the advent of those things, and some 30 years after they designed the uprights. So latent casting deficiencies, 30+ yrs of wear and tear, + unexpected usage could quite easily = unforeseen failure. Meanwhile, the engineers who are designing the billet CNC or fabricated uprights are also designing, for the same parts makers, the correction tie rod ends. And they are designing and building these with motorsport (or, at the very least, the meth addled antics of drifters) in mind. So I would hope (in fact, I would expect) that their design work included the offset of that steering force. Doesn't mean that it is not totally valid to ask the question of them, before committing $$.
    • The downside of this is when you try to track the car, as soon as you hit ABS you get introduced to a unbled system. I want to avoid this. I do not want to bleed/flush/jack up the car twice just to bleed the f**kin car.
×
×
  • Create New...