Mark III Build

[Detroit Bill]

Porsche went to a new home today. Sad to see it go.

[sierramadre]

Congrats. That's going to be a sweet ride. Really like the way you personalized it and made it more contemporary.

[Detroit Bill]

Getting closer. Will go for a dyno session tomorrow morning. Carb is not in yet. Seem like some day I may actually have a car. Hopefully before the snow flies.

[patrickt]

Originally Posted by Detroit Bill

Getting closer. Will go for a dyno session tomorrow morning. Carb is not in yet. Seem like some day I may actually have a car. Hopefully before the snow flies.

Where is the actual car?

[Detroit Bill]

Engine is done. Dyno'ed at 562 hp at 5600 rpm and 578 tq at 4100 RPM.
I was disappointed that it came in below the target set but doubling back to correct it would take time I do not want to spend as the summer slips away. Given more time on the dyno I think more power could have been realized but I could not stay longer unfortunately. I want to have it tuned in the car on a chassis dyno which is more important. I'll see how I feel about the driveability and power before I do that.

An interesting test we did do was to run the engine with and without the air cleaner. It is not an exact test because adding the air cleaner richens the mixture. So you would really want to make adjustments for max numbers with the air cleaner on and off.

I got Acton's Maxx air cleaner base, a K&N filter and K&N 9" Extreme round top. I also will have a Turkey Pan.

The Numbers came in at 556 hp and 575 tq at the same RPM's as above. Any filter is going to have some effect but for the small size of that filter (9 x 2-1/2 tall with the Extreme top) the effect was minimal.

[DWRAT]

Originally Posted by Detroit Bill

I was disappointed that it came in below the target

I agree with you here.
I personally think you should send that low HP motor my way and I will be very happy to deal with it.

You're gonna have one hell of a ride very soon.

[Detroit Bill]

Originally Posted by DWRAT

I agree with you here.
I personally think you should send that low HP motor my way and I will be very happy to deal with it.

You're gonna have one hell of a ride very soon.

Yea, I know it is plenty but the goal was 600 and that is not close.

[patrickt]

Originally Posted by Detroit Bill

Yea, I know it is plenty but the goal was 600 and that is not close.

You will never, ever, ever, ever be able to tell the difference. Never.

[Detroit Bill]

Originally Posted by patrickt

You will never, ever, ever, ever be able to tell the difference. Never.

Apparently I think I have a small pecker and I wanted the bragging rights to say 600. The ultimate problem is I am honest.

[RodKnock]

Originally Posted by patrickt

You will never, ever, ever, ever be able to tell the difference. Never.

Never is a very long time.

Bill, personally, I think if your target was 600, then your target should have been met. But that's just me.

[66gtk]

That engine is a monster! I don't think you are going to need/want more power in your SPF. You already have twice what you need to easily kill you. Looks like fun, though - beautiful, too. Thanks for sharing this journey with us. Can't wait to see your finished Cobra.

[Detroit Bill]

The builder supplied a graph which had two scales for HP and Torque and was difficult to read. I entered the numbers in excel to get a better visual representation of the result.

Graph without filter


Data without filter


Data with filter

[66gtk]

Beautiful FLAT torque curve you got there. Should be a real fun car indeed!

[RodKnock]

Could you do a better job at least?

[patrickt]

Originally Posted by RodKnock

Could you do a better job at least?

No, not without being paid a ridiculous fee. But you know that dyno sheets are the equivalent of financial statements for companies that carry off-the-balance-sheet debt.

[RodKnock]

Originally Posted by patrickt

No, not without being paid a ridiculous fee. But you know that dyno sheets are the equivalent of financial statements for companies that carry off-the-balance-sheet debt.

Lawyers! Always looking for handout or at least billable hours.

Are you telling me that engine builders fudge dyno numbers? So what you're saying then is that your 428's "honest" 450HP is actually smaller than that?

Wow, it might be faster pushing it, of course, you would have to find it in the garage first.

[blykins]

Undriveable? No. However, I suppose it comes down to what you consider "driveable". In your PMs to me from several months ago, you kept saying that you felt 600 hp was "over the top" and you weren't sure you would use it. Honestly, those are legitimate concerns. Guys get over-fixated on a number. Why 600? Why not 650? Why not 700?

I would imagine that some tuning without the air cleaner to optimize the A/F ratio, would have got you closer to your goal. However, you're going to put the air cleaner right back on it, plus choke it out with under-hood air flow and temperature.

Honestly, I think you probably shot Barry in the foot by crippling the engine with that air cleaner (it's not anywhere near optimal for that size engine).

Don't get me wrong, communication is key in any transaction and there has been times where we've all stunk at it. However, I personally think you're being over-critical given the circumstances.

[olddog]

Your welcome to your feelings I will not argue with that, but the flat torque curve on that engine is exactly what I would want in an engine.

A little more cam/springs or some porting and sure you could get the last 40 Hp, but I would bet you will loose more torque down low, where you will be driving 95% of the time, than you will gain up top. No sir, I wouldn't touch that engine. Glad you feel you don't want to take the time, as you are going to like this engine more than the one you wished for. "Thank God for unanswered prayers."

At least that is my opinion.

OBTW
On an engine if this size 1 deg of timing can make a 50 hp change. A little higher octane fuel and some wreck-less timing and he could have made the target. A less scrupulous builder ????

[patrickt]

Originally Posted by blykins

Don't get me wrong, communication is key in any transaction and there has been times where we've all stunk at it. However, I personally think you're being over-critical given the circumstances.

The problem is that the personality traits that afford someone the ability to drop six figures on a stupid toy are the some traits that can make them difficult to deal with.

[blykins]

You're preaching to the preacher.