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Old 18th September 2003, 01:09 AM   #1 (permalink)
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347 dyno results

Hi,
Just thought I'd share with you the results of the dyno tuning of the injected 347 windsor in my 40. Note the power is rear wheel power and if any of you bright boys (or girls) out there can translate the tractive effort figure into something that makes some sense like foot/lbs or newton metres that would be great. - I'm not that smart!

Basic specs are :
347 eagle stroker crank,
Eagle "I" beam rods,
KB hypereutectic pistons,
Comp cams hydraulic roller cam (224 / 232@ .050 with 112degree lobe separation)
Roush cast iron heads ported to 266cfm@ 25" H2O on the inlet side,
Victor jnr inlet manifold,
1050cfm 4 barrel throttle body,
Headers are 4 into 2 (Non cross over)
Wolf 3d (V4) ECU
running on 98 octane pump fuel(BP ultimate)
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Old 18th September 2003, 01:23 AM   #2 (permalink)
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Re: 347 dyno results

342RWHP @5800rpm
1460lbs tractive effort @ 4600rpm


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Old 18th September 2003, 09:12 AM   #3 (permalink)
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Re: 347 dyno results

What is the cam number (e.g. 282 HR)?

I assume that the car was tested on a Chassis dyno? Maybe the tractive effort is the force produced by the wheels on the drums. If this is the case you would then divide by the tire rolling radius and the OVERALL gear ratio that you were in (selected gear times differential). We know it made 310 ft-lbs at 5800 RPM (based on HP and RPM). So I would guess that performing the math as above would result in something like 350 - 375 ft-lbs.
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Old 18th September 2003, 08:48 PM   #4 (permalink)
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Re: 347 dyno results

Heres a formula for tractive effort:

Tractive effort

Cheers,

Danny

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Old 18th September 2003, 09:16 PM   #5 (permalink)
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Re: 347 dyno results

What is compression and cam lift? To be honest it seems a little bit low for the hardware, but the cam and induction may be playing a big part in that.

If you have the horsepower curve you can calculate torque.

torque = HP * 5252 / RPM

R
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Old 19th September 2003, 05:33 AM   #6 (permalink)
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Re: 347 dyno results

I remember when I had my first and only time with a rolling road and when they do that first power run it scared the poo out of me! All that noise and no forward motion! Roy said the same when his car was done recntly too.

However reason for post was to ask about your carb. 1050 cfm seems mighty big. Is it a holley? What reasoning lead you to use this size? Output wise I guess my engine is similar to yours but with different bits in it. However carb is just a 600 (or 650, I can't remember now!) cfm double pumper.

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Old 19th September 2003, 11:14 AM   #7 (permalink)
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Re: 347 dyno results

Malc -
1050cfm quoted is likely to be the max that can pass through the throttle assembly being used (remember unit is injected) like the Edelbrock throttle assy used by Dave on his R42.

The actual flow requirement will be goverened as usual by the capacity, cam profile, valve size - ports sizes etc etc.

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Old 19th September 2003, 09:05 PM   #8 (permalink)
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Re: 347 dyno results

Garry,
The cam is Comp Cams part no #35-518-8, Grind No #FW XE274HR Gross valve lift is .55 int / .565 Exh

Ron,
Compression is in the region of 9.5:1

Malcolm,
Paul is quite correct, the throttle body value is the max flow rate and is used in a multipoint injections etup so in effect is really only an air valve. It is quite a nice piece of gear readily available from EFI hardware.
http://www.speed-technology.com/efi_throttle.html

I am considering fitting a stepper motor / IAC valve to control the cold start idle just to help things along a little also.

The engine has been limited 5800rpm at present so there would still be a little more power available. The guy doing the tune did say he went conservative with the timing etc as he preferred more milage before going for outright power. I want to get some miles on it before raising the rev limit fruther but do not think I will be going past 6500rpm. Mind you, 340hp at the tires pushing 900kg aint that bad when your in the hot seat as it is.

Question for you guy's, do you think quad down draft throttle bodies will make much of a difference? I went for the 4bbl for three initial reasons.
1. Drivability (on the street more than the track,
2. To learn what the car is capable of before getting too silly and
3. $$

Best wishes to all.

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Old 20th September 2003, 05:24 AM   #9 (permalink)
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Re: 347 dyno results

Rick,
Where did you get this Camshaft? I can not find it in the Comp Cams catalogue. Similarly, the cam quoted to me by AFR doesn't exist according to Comp Cams??? Can anyone help?

Brett
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Old 20th September 2003, 01:10 PM   #10 (permalink)
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Re: 347 dyno results

Nicely done Rick!

Brett,

Comp Cams does custom grinds based on your engine configuration. I suspect these grinds are available if you call their tech line.
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Old 22nd September 2003, 01:56 PM   #11 (permalink)
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Re: 347 dyno results

Rick

I doubt switching to 8 bbl injection would add a LOT...
if you were looking to bump HP, I suspect either cam
or headwork would be more cost effective.
However, you can't beat the visual and sound affect of the 8 bbl, which I suspect is the primary reason people do it.

MikeD
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Old 22nd September 2003, 05:37 PM   #12 (permalink)
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Re: 347 dyno results

Rick can you post a larger version of the plot? At what lift was the intake flow equal to 266 CFM. If that flow is at ~ 0.5" lift it should be good for up to 500 HP at the flywheel. It may however require you to go to a solid roller cam to get the RPM's required to get obtain that power for that displacement engine.

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Old 23rd September 2003, 01:11 AM   #13 (permalink)
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Re: 347 dyno results

attempt 2!!
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Old 23rd September 2003, 09:18 AM   #14 (permalink)
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Re: 347 dyno results

Looks like HP is still climbing. I would expect that the crank and rods are good for runs to 6500 RPM. Cam will probably begin mild float at 6300. The torque peak was a something like 4700 RPM so I would expect the HP peak to be at ~ 6000 RPM. You could do a full pull up to 6300 and see how it goes. Remember you are going to loose about 15% HP from flywheel to rear wheels.

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Old 23rd September 2003, 08:27 PM   #15 (permalink)
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Re: 347 dyno results

[ QUOTE ]
To be honest it seems a little bit low for the hardware, but the cam and induction may be playing a big part in that.
R

[/ QUOTE ]

Ron, part of the "low" power figure can be attributed to the fact that Dyno Dynamics dynos by design will always show lower power levels than the more widely used Dynojet dyno.

Here's an email from a dyno shop that have both the Dyno Dynamics and Dynojet dynos. Based on his experience, Rick's motor is making 393 Dynojet rwhp.

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Old 24th September 2003, 01:15 AM   #16 (permalink)
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Re: 347 dyno results

Gary,
The heads are the Roush 5304 Cast Iron items. Out of the box they were tested at 237cfm (515hp)inlet and the exhust flowed 63% of the intake this was with 2.02" inlet and 1.06" exhaust valves at .600" lift.

After port work the heads were retested and flowed 266cfm (580hp) but the exhaust flowed 78% of the intake also at .600" lift.

Note that each test was at 25" H2O and with 6" of 1-7/8" exhaust pipe.

We expected in the region of 400hp at the flywheel from the motor and really were aiming at a strong torque motor for hill climb type events and street use. I am pretty happy with the end result.

Cheers,
RV
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Old 24th September 2003, 08:38 AM   #17 (permalink)
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Re: 347 dyno results

RV
Thanks. Do you have the gear ratios and tire diameter to do the torque calculation? Just curious.
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Old 25th September 2003, 01:03 AM   #18 (permalink)
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Re: 347 dyno results

The rear tyres are 255/45 x 17 which equates to a measured 25.5" diameter.

The gears are the standard AAZ ratios in the 016 audi box which can be found on this site.

Regards,
RV
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Old 25th September 2003, 08:39 AM   #19 (permalink)
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Re: 347 dyno results

The only other thing required would be the actual gear they were using during the test (4th??).

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Old 27th September 2003, 12:53 PM   #20 (permalink)
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Re: 347 dyno results

[ QUOTE ]
To be honest it seems a little bit low for the hardware, but the cam and induction may be playing a big part in that.
R

Ron, part of the "low" power figure can be attributed to the fact that Dyno Dynamics dynos by design will always show lower power levels than the more widely used Dynojet dyno.

[/ QUOTE ]

Never used anything but a dynojet. Seems to me though that these fellows should be correcting for internal losses in their machines or differences and putting horsepower out on the graph. Obviously not as two dynos are gviving two very different numbers for horsepower (I am well aware of the statistical differences that will be present with two measurement instruments trying to measure the same thing).

But, these differences are much more than what one would expect to statistically be present.

Here is why I say this: 1hp = 746W = 76 kg*m/s = 550 ff*lb/s = 42.5 btu/s (there are many different hp ratings, metric, british, water, etc. but they are all basically the same). Any of these are fairly easy to measure using a variety of methods and is certainly what is done one way or the other.

So, while I understand that the two machines do not produce the same numbers one or both of them are not doing their homework - they're not displaying hp correctly.

At any rate, I'm familar with the dynojet and 393 rwhp is a good number for the motor and more in line with what I would expect from the setup. Good job!

Ron
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