521.45hp

[enkeivette]

That's what I get, assuming a 17% loss. That's nothing to cry about right? Especially not with an air to fuel ratio between 14 and 15:1, a slipping belt, only 32 degrees total timing at only 6lbs of boost hot air. Excuses, excuses, excuses. :D

432.80 / 83 X 100 = 521.45

Man, dyno day is always depressing for some isn't it? Felt like we broke some hearts at Magnaflow today.


Hey Ben, I noticed that there is a bump in my A/F curve at 3K rpm. It jumps over 16:1 real quick. Does yours have a bump in it right before WOT?

[SeanPlunk]

Cough Cough, it's 15%, cough. By my math you're pushing no more than 509.176471 hp or 10.823529 less than a stock 08 Lamborghini Gallardo. Of course that also puts you up roughly 85hp up on a certain Cobra I know, and about 409.176471 hp up on a certain Turbo Buick I know.

[SeanPlunk]

In all seriousness though, your car is a beast Adam, I was quite impressed :bigthumbsup: Ben too for that matter.

[Vettezuki]

. . . Hey Ben, I noticed that there is a bump in my A/F curve at 3K rpm. It jumps over 16:1 real quick. Does yours have a bump in it right before WOT?

No bump. It drifts from 14 to 15 between 2.5 and 3k and is pretty flat at 14 for the rest of the way.

But I like this statistical fact. Your blower motor is making 68.60hp/liter. My NA motor is making 68.72. So neener neener neener. :p

[enkeivette]

...and about 409.176471 hp up on a certain Turbo Buick I know.

:nutkick:Hahaha, you're a dick.

And Ben said that stick cars are between 15 and 17 percent, so since my car has IRS don't forget, I pick 17. And since it's common knowledge that Ben is smarter than Sean, we can infer that 17 is a reasonable estimated loss. Haha. :D

No bump. It drifts from 14 to 15 between 2.5 and 3k and is pretty flat at 14 for the rest of the way.

But I like this statistical fact. Your blower motor is making 68.60hp/liter. My NA motor is making 68.72. So neener neener neener. :p

Must be my acc pumps. I should probably upgrade to the 50cc pumps to get rid of that little hesitation.

And yes, your motor is awesome Ben. Even though you cheat with Torco, just kidding!!! I was thinking about how amazingly efficient your motor is, being NA and all. And getting awesome gas mileage, AND still having AC, AND still having an acceptable ride. Whilst mine is not so comfortable or efficient.

But keep in mind, in my car's defense (being supercharged and all) she's only at 6lbs. And she's a world away with a smaller pulley and a $250 intercooler. I can run 15lbs with this setup intercooled on 91 octane.

[enkeivette]

I thought of yet ANOTHER lame excuse. The second pull made (as you'll see on the dyno sheet) an average of 10-15 more hp before he had to let out at 4750 rpm.

However, to play Devil's advocate with myself, there is never how fast your car can be, only how fast your car is.

[Vettezuki]

. . . However, to play Devil's advocate with myself, there is never how fast your car can be, only how fast your car is.

Addendum, "It's never how fast your car can be, only how fast your car is. However, it is how fast my car can be."

[Vettezuki]

I thought of yet ANOTHER lame excuse. The second pull made (as you'll see on the dyno sheet) an average of 10-15 more hp before he had to let out at 4750 rpm.


What was your torque, 425? Let's go ahead and be generous and say your torque would stay constant to a redline of 6,000rpm. That equates to 485WHP and therefore, about 557BHP.

[enkeivette]

Addendum, "It's never how fast your car can be, only how fast your car is. However, it is how fast my car can be."

No no, I didn't mean it like that. I meant the royal "you." I was referring to myself. As of this day, my car is good for 432 whp. That's it, period.

What was your torque, 425? Let's go ahead and be generous and say your torque would stay constant to a redline of 6,000rpm. That equates to 485WHP and therefore, about 557BHP.

???


Hey Ben, my Mercedes tech buddy seems to believe that a 14-15:1 A/F ratio is dangerous for WOT. So I've decided to richen it up based on that.

You said that your A/F ratio was similar under WOT, why don't you richen it up to 12-13:1, you'd gain power obviously, it would be safer, and you might be able to get away with just 91 octane. I can't think of any reason not to bump up the fuel pressure.

[Vettezuki]

. . .

Hey Ben, my Mercedes tech buddy seems to believe that a 14-15:1 A/F ratio is dangerous for WOT. So I've decided to richen it up based on that.

You said that your A/F ratio was similar under WOT, why don't you richen it up to 12-13:1, you'd gain power obviously, it would be safer, and you might be able to get away with just 91 octane. I can't think of any reason not to bump up the fuel pressure.

It may be slightly different for DOHC engines than Pushrod, but I don't know. On Naturally Aspirated Gen III motors, 14:1 is about ideal for A/F efficiency. A bit richer at lower rpm (I'm close to 15 down low), would improve torque under the curve.

Running too rich (and I think 11-12 is too rich, even for your application probably), means LESS power, more hydrocarbon emissions (unburnt fuel) and and less mpg. Running too lean means you emit more NOX and run the risk of dangerous detonation (like bye bye engine territory).

It gets pretty complicated and I don't know all the theory for sure. However, it is my understanding A/F and timing is quite a bit different on Forced Induction motors than Naturally Aspirated. I suppose in the simplest terms, timing is often comparatively retarded and the A/F comparatively richer.

The point is that the same A/F and Timing curves are not equally well suited to different engines.

In my case, my biggest potential gain for power will come from timing. I'm only at about 18 at 4K. That's because it was tuned on 91 to avoid detonation. Because it's a fairly hi-comp motor, getting the timing up from peak torque, might punch it up a fair bit.

[Vettezuki]

. . .
???
. . .

Que? Are you wondering how I came up with 485 -> 557 HP?

[enkeivette]

Yes indeedio.

[Vettezuki]

Yes indeedio.

The following is my current (and hopefully sufficiently accurate) understanding:

Torque is a force that tends to rotate.

Work = Force x Distance

Horsepower is a unit for measuring the rate of doing work.

1 HP = 33,000 foot pounds per minute. (There's an interesting history to this number. Look up horsepower on "How Stuff Works".)

Therefore we derive HP thusly.

HP = Torque (in ft/lbs) x RPM (how many "times" the force is applied in a minute) / 5252 (a constant - don't remember how it was derived).

Assuming peak torque of 425 ft/lbs is sustained at 6,000rpm:

HP = 425 X 6,000 / 5252
HP = 485

Since we're measuring torque at the wheels, that's HP at the wheels.

Factoring back in driveline loss at conservatively 15%
485 x 1.15 = 557

A dynometer measure torque at rpm and plots the hp curve.

[Vettezuki]

BTW, what was your peak torque? Here's your algebra homework. If you were making 432WHP at 4,750 RPM, what was your WTQ? Hint, it was higher than 425 . . . If you were making 432WHP at 4,750, then the scenario above would be much higher.

[enkeivette]

So if an IRS car with a manual trans loses 15%, how much does a solid axle car with a manual trans lose?

[Vettezuki]

So if an IRS car with a manual trans loses 15%, how much does a solid axle car with a manual trans lose?

I may be corrected, but I don't believe an IRS looses any more power. Driveline loss is power consumed by friction and moving the driveline itself. In this sense, there isn't much difference between a solid axle and IRS (to my knowledge), though there might be some I suppose. The big deal for an IRS vs. Solid axle is traction in straight line. (Not to mention basic strength.) In other words, and Sean can clarify, I don't think the dyno numbers for the solid axle F-Body were any different than the IRS Y body with the same LS1.

[SeanPlunk]

Sorry Ben, actually not true. IRS cars are generally thought to eat slightly more HP. There is a famous magazine article where an LS1 Fbody does in fact out dyno an LS1 Vette.

[enkeivette]

Think about spinning 6 u-joints as opposed to just the 2. Not to mention, a halfshaft (or an axle) is rarely parallel with the ground. They typically angle down (or in my case up) which also causes some more resistance. Not to mention, the added weight of a halfshaft, yokes and u-joints as opposed to a simple slip in axle.

I'm positive that our IRS would eat more power than a C5/C6 IRS.

I've always been told that a solid axle stick shift car loses 15% to the rear wheels. While an auto can lose 20-25% to the wheels. So, it makes sense to me that an IRS stick shift car would lose between 15 and 20.

[Vettezuki]

Sorry Ben, actually not true. IRS cars are generally thought to eat slightly more HP. There is a famous magazine article where an LS1 Fbody does in fact out dyno an LS1 Vette.

It's cool yo, I didn't know. I can imagine a slight loss because of the gemoetry and connections, but how big are we talking? What's the physics behind it?

[Vettezuki]

Think about spinning 6 u-joints as opposed to just the 2. Not to mention, a halfshaft (or an axle) is rarely parallel with the ground. They typically angle down (or in my case up) which also causes some more resistance. Not to mention, the added weight of a halfshaft, yokes and u-joints as opposed to a simple slip in axle. .

Yeah, I guess it adds up. I know my motor (with headers, a Y body airbox, and more aggressive tune, but NOT an LS6 intake) was dynoing at 432 in the Vette it came out of. I guess this could account for some of the difference. With my fairly conservative tune, stock manifolds, and hotter air intake, the best I've gotten was 391; that's quite a difference.

[enkeivette]

Sorry Ben, actually not true. IRS cars are generally thought to eat slightly more HP. There is a famous magazine article where an LS1 Fbody does in fact out dyno an LS1 Vette.

http://www.dark-earth.net/images/proofofpower.jpg

[Vettezuki]

I remeber this now. So, what's a fare driveline loss assumption for a C3 IRS? 17%? ? This is closer to what I would have "guessed" in the first place. Is it more maybe?

I know the motor I have in my C3 Vette, which pulled a 391 at this event, dynoed 432 in the C5 Vette it came out of. That was with Headers and a much more aggressive tune. Curious to see what I get with Headers and a Tune. . .

[enkeivette]

I just got off the phone with ATI, I was calling for a pulley recommendation to get me up to 15 lbs. I told him that I'm getting 5 1/2 now with my 4" pulley and he told me that my belt must be slipping a lot. He said that a similar motor made 10-12 lbs with my pulley. He said that the boost should build with rpm, and it doesn't. Mine stays at 5 1/2 from 3K rpm to 6K rpm.

So I'm going to tighten the crap out of the belt and see what happens.

[Vettezuki]

I just got off the phone with ATI, I was calling for a pulley recommendation to get me up to 15 lbs. I told him that I'm getting 5 1/2 now with my 4" pulley and he told me that my belt must be slipping a lot. He said that a similar motor made 10-12 lbs with my pulley. He said that the boost should build with rpm, and it doesn't. Mine stays at 5 1/2 from 3K rpm to 6K rpm.

So I'm going to tighten the crap out of the belt and see what happens.

I don't think it's related to your boost issue, but what's the story regarding your vacuum? Are you going to get a pump?

[enkeivette]

I don't think it's related to your boost issue, but what's the story regarding your vacuum? Are you going to get a pump?

I need to get a better job first. My company has not given me work in weeks. I'm more broke than a GN engine. :jk: Law school apps are $72 on average, I've submit 9 so far. :barf:

I've been thinking about doing a high flow evacuation system using the SC itself.

If I route a larger hose (heater hose size) to the top of the air filter, run that directly to the valve cover, and open up the breather hole and cut out the baffling on the other side (I have stud girdles to control the oil) it might be sufficient.

[SeanPlunk]

I'm calling you out Adam - you have to bring your car out to the street legal event on the 26th. No more excuses :judge:

[Vettezuki]

. . Law school apps are $72 on average, I've submit 9 so far. . .

Out of curiosity, do you have anybody read them prior to submission? Ah just teasing. . .

[enkeivette]

Out of curiosity, do you have anybody read them prior to submission? Ah just teasing. . .

Just like 3 people! Haha, I've been accepted to one already. So now I just need to wait and pick the best school that accepts me.

Sean, is it free? If you want to see how fast my car is that bad we can do a run down Crowther. I've got nothing to hide. Just my small penis.

[Vettezuki]

Just like 3 people! Haha, I've been accepted to one already. So now I just need to wait and pick the best school that accepts me.

Sean, is it free? If you want to see how fast my car is that bad we can do a run down Crowther. I've got nothing to hide. Just my small penis.

We need some data entry (production vehicle database.) We'll gladly pay for you and your small penis to have a day at the track (and more) if you want some work.

[bgn8711]

Adam, I must agree dyno'ing your car and than not running it is for lack of a better term pussy. I SHOULD have my car done by than and if so will absolutely be at the track as well. Neal wants me to check if my car has a broken rocker shaft as he says our initial diagnosis was assumed without much thought to what else it could be but I don't think I have enough tools to rip off the valve cover as I don't think we have deep sockets. I talked to the automatic kings Sean they said it's 220 to restall it:eek:. It's 275 for a bitchin' ass brand new converter so fuck them. I say f the math come out and you can say my car runs XX in the 1/4 cuz that is all that matters anyway when it comes down to it. Jusy my .02, I will say dyno's are useful for tuning though so don't start crawling up my ass...insert joke here.

Brian

[SeanPlunk]

Adam, I must agree dyno'ing your car and than not running it is for lack of a better term pussy. I SHOULD have my car done by than and if so will absolutely be at the track as well. Neal wants me to check if my car has a broken rocker shaft as he says our initial diagnosis was assumed without much thought to what else it could be but I don't think I have enough tools to rip off the valve cover as I don't think we have deep sockets. I talked to the automatic kings Sean they said it's 220 to restall it:eek:. It's 275 for a bitchin' ass brand new converter so fuck them. I say f the math come out and you can say my car runs XX in the 1/4 cuz that is all that matters anyway when it comes down to it. Jusy my .02, I will say dyno's are useful for tuning though so don't start crawling up my ass...insert joke here.

Brian


What time are you thinking of going down on Saturday to San Diego?

[bgn8711]

8:30 ish :/ can Adam do that??

[enkeivette]

Assuming they used a 6 speed for the solid axle F-Body, we can assume a 15% loss.

So 292.8/ 85 X 100 = 344.5 Sounds like 345hp at the engine to me.

Assuming the Corvette LS1 is the same as the F-Body LS1 we can calculate the difference of the IRS, assuming also that they used a 6 speed.

285.6 / 344.5 X 100 - 100 = 17.1% You were off by .1% Ben! WTF?! :)


By the way, I doubt that the C3 trans/ IRS will be as efficient as a C5 transaxle.

[SeanPlunk]

8:30 ish :/ can Adam do that??

Yeah, although I think we're going to go to Cars and Coffee before hand and then head down. Alexis and Rachel are going to drive down with us and while we work they may go into San Diego. That's the unofficial plan anyway. Have you talked to Neal yet?

[bgn8711]

Yeah, although I think we're going to go to Cars and Coffee before hand and then head down. Alexis and Rachel are going to drive down with us and while we work they may go into San Diego. That's the
unofficial plan anyway. Have you talked to Neal yet?

Yeah, I've been talking to him everyday about things...He's been such a help with everything I just am dying to get this thing back together and running. Should be a busy ass weekend...

[enkeivette]

Finally got around to buying a multimeter (which sucks, I'm going to return it) so I opened the hood to find the cause of the rough acceleration that I've had since the DC tour.

I was guessing that it was going to be a stuck lifter, but I decided to check the basics before I even pulled the valve covers off. I checked the impedance of all of the plug wires and this is what I got:

Cylinder #8 - 91.6 ohms
Cylinder #6 - 100.4 ohms
Cylinder #4 - 121.4 ohms
Cylinder #2 - OPEN! :eek:
Cylinder #7 - 152.2 ohms
Cylinder #5 - 127.5 ohms
Cylinder #3 - OPEN! :barf:
Cylinder #1 - 152.2 ohms

So I guess during the dyno run I had two open plug wires! I don't think that it would make a difference in hp, because at those rpms I'm sure the spark would just arc over the dead spot in the wire, without a problem.

I cleaned up and put some new terminals on these wires the day before the DC tour, unfortuantely I didn't have a multimeter at the time to check the impedance before I installed them. I just fixed them tonight, they both measure around 100 ohms now, I'll install them tomorrow. Hopefully that was the problem.

[enkeivette]

http://www.motorgen.com/forum/showthread.php?p=1703#post1703