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Posted: Tue Nov 26, 2013 2:19 pm
by Merlin
It's cool. The graph isnt correct which is the problem.

This is what it should look like:

Image

In fact my graph and the one above are the exact same until 4.5K which is where the problems with the Hypertech dyno starts.

Posted: Tue Nov 26, 2013 2:21 pm
by Dino
BMCC: A Flat torque curve is what it is.. its making nearly 90% of its torque from 3500 rpm.
Most turbo cars have peaky torque curves and people map them to have the power torque held on to.
Vtec means nothing, its just a peaky power delivery.
The less difference in power/torque jumps makes for better driveability.
So i wouldnt say it does nothing for the car.

Iain, 1st live graph was a wheel reading, the second is the printout of the calculated flywheel bhp at Powerstation.

Guys dont be disheartened by any of your graphs.
So many different dynos, factors, operators, etc.... dont get held up on figures.

Posted: Tue Nov 26, 2013 2:30 pm
by honda-hardy
Image

whats going on here? hp dips quite a bit until vtec kicks in at 5.2k.

Posted: Tue Nov 26, 2013 2:31 pm
by BMCC
Dino wrote:BMCC: A Flat torque curve is what it is.. its making nearly 90% of its torque from 3500 rpm.
Most turbo cars have peaky torque curves and people map them to have the power torque held on to.
Vtec means nothing, its just a peaky power delivery.
The less difference in power/torque jumps makes for better driveability.
So i wouldnt say it does nothing for the car.
VTEC in that graph gains you nothing. In the graph Merlin's just put up VTEC gains you something. What the point of having a high lift (high duration? can't remeber :lol: ) cam if you get nothing from it? Ok in the graph you don't lose anything but still I'd want my VTEC to give me some form of performance increase rather than just not losing me anything.

Posted: Tue Nov 26, 2013 2:36 pm
by rob quilter
Wow, that dynos way out! A little bit out is understandable.

Posted: Tue Nov 26, 2013 2:38 pm
by Merlin
BMCC Look at Dino's graph at the top of the page. At 6.5K bhp rockets, climbing from 220bhp to 280bhp, as the torque and rpm increase together. In my graph the dyno isnt reading torque correctly (the whole issue with this dyno) and since torque isnt climbing the bhp is only being increased though the rise in rpm .

HH you sometimes see a dip in torque before VTEC on stock H22's.

Posted: Tue Nov 26, 2013 2:41 pm
by Confused
Also, remember, that different dynos do different things with their "wheel hp" figures to calculate the "flywheel hp"

The Maha at Powerstation usually gives a "low" wheel hp figure compared with other dynos, but they can't be compared because it's part of how it calculates stuff. The Maha dyno has 2 contact patches per wheel, which increases the drag - this reduces the "wheel hp" figure but is taken into account for calculating the "flywheel hp" (which, from my experience, is typically there or thereabouts correct)

Posted: Tue Nov 26, 2013 2:52 pm
by wurlycorner
Dino wrote: Iain, 1st live graph was a wheel reading, the second is the printout of the calculated flywheel bhp at Powerstation.
8-) I wasn't imagining it! :D

Posted: Tue Nov 26, 2013 3:01 pm
by BMCC
Merlin wrote:BMCC Look at Dino's graph at the top of the page. At 6.5K bhp rockets, climbing from 220bhp to 280bhp
Which I agreed with:
BMCC wrote:In the graph Merlin's just put up VTEC gains you something.
Dino wrote:BMCC: A Flat torque curve is what it is.. its making nearly 90% of its torque from 3500 rpm.
Most turbo cars have peaky torque curves and people map them to have the power torque held on to.
Vtec means nothing, its just a peaky power delivery.
The less difference in power/torque jumps makes for better driveability.
So i wouldnt say it does nothing for the car.
Which I diasgree with and here I am talking about the Hypertech graph restating a point I made earlier before the powerstation graph was put up:
BMCC wrote:What the point of having a high lift (high duration? can't remeber :lol: ) cam if you get nothing from it? Ok in the graph you don't lose anything but still I'd want my VTEC to give me some form of performance increase rather than just not losing me anything.
Now I think dyno print two (power station) is more realistic but my inital point made back a few posts back still stands as in the Hypertech graph VTEC appears to be gives you no improvement which is not the point of VTEC.

Any how my days going to the dogs at work so I had better get back to it! :P

Posted: Tue Nov 26, 2013 3:18 pm
by Merlin
BMCC wrote:in the Hypertech graph VTEC appears to be gives you no improvement which is not the point of VTEC.
Exaclty, which is what this thread is going on about. The Hypertech dyno is not giving accurate readings after VTEC engagement.

All Ludes make more torque once VTEC engages. As you say it is the whole point of VTEC to make more torque. I get wheel spin in 2nd and sometimes 3rd when VTEC kicks in (Yo). How can I wheel spin if there isn't a significant jump in torque. Hence why the Hypertech dyno is a sack of crap.