[drmo]

Are you doing dyno pulls in 5th gear? Can't see doing 220kph in 4th or you must have some really long gearbox.

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[malkolm666]

Yes, 5th gear. It gives me more acuurate digits in the log. 4th gear takes a little to short time to make the tune perfect.

 

[LotusElise]

Thank Markus! Btw the dimensions I gave you on the header was outside. I think it was 1.5-2mm pipes. Did you inculde that in your math?

I did.

I found out why the power is dropping like a rock after 7000rpm!...I found that the ThrottlePlate was closing after 7000rpm.

We had a discussion here years ago which is the best gear for calibration of the engine at the dyno role. One limit, I wrote, was the rotational speed of all rotating parts. The failures of measurement and the risk of a flipping car increases. On the other end, a to fast increasing engine speed also lowers the measurement and calibration quality, because of the delay in response time (t90 duration) in lambda metering, actuation of valve train phasing and so on decreases the quality too. So finally with OEM 6spd gearboxes 3rd and 4th gear will make it best. But breaking through the speed limit at 7000 rpm makes me really wonder what idea runs you to calibrate in 6th gear (6spd) or 5th gear (5spd, automatic) on a roller dyno? Do you know how much energy a 15" wheel incorporates at 220 km/h, especially once it vibrates more than on street because of the metallic knobs of the roller surface? Around 22-25 kJ of Energy, let a 100 kg weight fall down your feet from at least 2 m height, you know how much it is.

Rotational energy increases with power of two of engine or wheel speed! Going to 4th gear means a cut of almost 2/3 of that energy. I hope you are going to reduce the risk of tuning by choosing a lower gear for calibration of the ECU map. Or can't you fix the gear of your automatic gearbox for the tuning?

 

[LotusElise]

Yes, 5th gear. It gives me more acuurate digits in the log. 4th gear takes a little to short time to make the tune perfect.

Do you incorparate into the dyno power calculation process the increase in wheel diameter because of centrifugal forces? I do it for example for my virtual dyno measurement on street, but it is a model which corrects VSS and engine speed correlation, no measurement! Centrifugal force also increases with power of two of wheel speed. The enlengthening of the diameter is significant, cheating you a higher engine speed increase and a too big power curve at the high end. More accurate would be lowering the wheel speed! That what I mean with accuracy at 5th gear and beyond declines significantly.

All of course if you tune on the roller dyno. Axis dyno is not relevant in that.

 

[drmo]

Marcus, he probably has a low inertia dyno without a brake, so the runs in 3rd and 4th gear only take a couple of seconds which means tuning is really compromised.

Malcolm666, can't you make rough adjustments in 4th gear on the dyno to see how the engine behaves in higher rpms (7000+rpm) and make fine tuning on the road in 4th gear?

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[LotusElise]

Marcus, he probably has a low inertia dyno without a brake, so the runs in 3rd and 4th gear only take a couple of seconds which means tuning is really compromised.

Good arguement, drmo!

Something, I mean the low inertia, I wouldn't recommend. Especially part load calibration need transient and stationary operation of the dyno to be accurate in adjustments, so a braked dyno (eddy current, water, ...) is always more preferable over a high inertia roller dyno.

I agree with you, street fine tuning would open the door to see where the VE goes beyond 7000 rpm at lower gears, as the engine speed increase would be much slower in 4th gear compared to a low inertia dyno role. I could check the log data with my power calculation programm, I've done in VBA.

 

[malkolm666]

With the Accord it would be best to dyno on 4th, but my habbit is that I usually dyno k-series on 5th. All the k20-swapped cars with 15" runs to fast to tune correctly on 4th gear in EDM ep3 gearbox or JDM gearbox.

Within 200-300hk both my dyno and all the cars works best with even results when the dyno is braking 10% of its capacity. (300-400hp 20%braking and so on). My dyno has the capacity to brake 730KW.

Dynoing in 5th gear on my accord gives my a perfect tune for the street. My dyno works so perfect that the need of streettuning is gone. Im happy, my customers is happy and most important in life, my wife is happy. Going 200kmh when a Moose steps out in front of you when you have one eye on the lambdameter is kinda scary. I didnt put 2years salary in a dyno to keep on dyno on the streets..

I feel stupid that a didnt tried 4th on the dyno. That my fault. But Im happy going 5th gear and noticed this problem with the flashpro so Hondata can make a fix for it for everyone running a CL9/TSX/Accord.
Had been no fun to notice on the street or track when doing 220-240kmh.

 

[goforbroke]

This is an interesting discovery, no clue why Hondata put the limiter so low though or even put a limiter on it period.
I was running Flashpro on my TSX, but removed it and plan to reinstall it after
installing the rest of my parts.

Not sure it’s worth contacting them to remove it because I don’t plan on doing high runs at 137mph+, but you never know.....

I wonder if this applies to both generations of flashpro for the first gen TSX though.

Malkolm, what year is your TSX?

 

[malkolm666]

I run the 07-08 ecu.

My black Accord CL9 is from 2003.

In the next update on the flashpro-software it will be gone for everyone in the world.

I like kpro more, but its a headache to install it with dual ecus in the CL9. And also the cruise controll wont work with kpro.
Flashpro is cheap and keeps all the standard functions in the car.

 

[goforbroke]

I run the 07-08 ecu.

My black Accord CL9 is from 2003.

In the next update on the flashpro-software it will be gone for everyone in the world.

I like kpro more, but its a headache to install it with dual ecus in the CL9. And also the cruise controll wont work with kpro.
Flashpro is cheap and keeps all the standard functions in the car.

We are running the same gen software then because my TSX is a 08.
Yeah flashpro is a lot more user friendly especially for the TSX crowd which likes to keep the creature comforts. The swapped hatch guys don’t care about AC, PS, cruise control and etc...lol

Btw are you in New Jersey or across the pond, looking to have Jeff Evans tune my car but you might be another resource also.

 

[malkolm666]

Im in Europe. Jeff Adams and Derek/D-rob seems to be two of the best tuners in the states. It cant go wrong when using one of them. They have excellent skills.

 

[goforbroke]

Im in Europe. Jeff Adams and Derek/D-rob seems to be two of the best tuners in the states. It cant go wrong when using one of them. They have excellent skills.

Yeah I’m aware of them both, regardless looking forward to your test. Also good to see a built motor in our chassis.

 

[malkolm666]

4th gear pull. Only had time to do 3pulls today. No tuning. All of them was 300hp+. Best was 303,6hp@283nm.

 

[drmo]

That is nice result. Maybe a little low on torque for the setup but still ok.

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[LotusElise]

4th gear pull. Only had time to do 3pulls today. No tuning. All of them was 300hp+. Best was 303,6hp@283nm.

Thanks for sharing it. Good to see you solved the issue, and it doesn't relate to the header basically :up:. My engine simulation of the setup, which is similar to yours beside cams, didn't show any chance for that from dimensioning side. That's also good to see, it has it's eligibility (s. #34 and #36) .

...Maybe a little low on torque for the setup but still ok...

As simulation with DC OG design lobes shows (cam data of DC OG 4.0 as reference), these are good cams in terms of wear and noise. They come alive late on the engine speed side, therefore the engine setup must fit their character to utilize their shiny side: port size, valve size, intake runner lenght and diameter, header dimensioning, .... I would have expected to see peak power with them at 8.5 krpm and to see the engine chocking at 8.8 to 9.2 krpm with such an adapted setup. A TODA (C or better D) lobe design would lift the torque over the actual setup, especially in the midrange, therefore it would be a better fit for a 5spd automatic gearbox with DD character :twocents:.

 

[an2ny888]

Lotus elise, how would a toda A3 cam work on this setup?

 

[LotusElise]

Lotus elise, how would a toda A3 cam work on this setup?

I haven't the time to tune the VTC map for the engine simulation, but the same VTC map tells me following:

• before 7.2 krpm the TODA A3 produces more VE than the TODA C, beyond that the TODA C has higher VE, once I use a TODA header
• the engine simulation of the RRC IM engine setups are challenging, the solver need much more time to find a solution due to the bell mouth shape and the calculation cell size. About 30 minutes for 10 engine speed points, too much to run 6 total rev range runs for VTC and VTEC tuning. Anyway, the TODA cams make the torque curve more peak'ier, more midrange torque compared to DC OG 4.0 and, depending on header, less torque in the high end.

Like stated above, the DC cams need a good flowing and harmonizing intake and exhaust setup to utilize their performance potential. Same to the TODA cams, a beefy midrange design of IM and H could bring them into astonishing torque values. Here the setup is mix, the RRC is a midranger, the header more a top ender, the head ports I just can guess midranger and the cams top ender. The bottleneck for peak power here seems to be the IM and the cylinder head. On the other side putting a TODA cam on a 13.0:1 CR is hard stuff for MBT tuning when using 91-93 octane fuel. The huge lobes and the retarded Centerline of the DC cams help to lower VE and to increase turbulent kinetic energy of the trapped air and fuel to keep knock limit more far away.

So finally the result with the TODA A3 could be less impressive on dyno compared on the simulation result, due to the choosen CR. The setup here is not really a specialist for a certain application, it is a mix of characteristics in their parts, making it difficult to utilize their potential.

I would have choosen a 12.0:1-12.5:1 CR a smaller cam to fit the VE capability of the RRC IM, the actual header would do a favour to this engine setup too, something a 5spd automatic gearbox would make happy, lower revs at same power, less noisy, more driveable, more reliable...to adapte the actual small block, the head need high flow ports and IN valves, the actual cams and IM like the S2 Ultra, Hayward center feed style or VE specialists like ITB's, but the noise level in a DD 5spd automatic is awefully :twocents:

 

[malkolm666]

, the actual cams and IM like the S2 Ultra, Hayward center feed style or VE specialists like ITB's...

I have the S2 Ultra Street manifold in my shop, should I try it? Or is my engine not worthy?

 

[drmo]

I have the S2 Ultra Street manifold in my shop, should I try it? Or is my engine not worthy?

You can try it but I think you will loose some torque in the lower and middle to gain up top.

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[LotusElise]

I have the S2 Ultra Street manifold in my shop, should I try it? Or is my engine not worthy?

You can try it but I think you will loose some torque in the lower and middle to gain up top.

Yes, the info of deibral coincides with that drmo (s. http://www.k20a.org/forum/showpost.php?p=3147226&postcount=56).