Closing in on 145 MPH

[Speedy!]

So on stock boost this is being achieved, I assume, by adding a considerable amount of ignition advance. I wonder at what point adding advance no loner produces results? I believe at some point things tip over? Seems quite a bit of overhead for advancing timing based on your results PH. I run Renegade race fuel and their tech director and I had a nice chat about fuel, timing, etc. He claims I can put as much timing in the car as it will make power on with this fuel, thus my curiosity.

Mine picked up 26mph on the back half on 93 in 3600 DA. Never really paid much attention till you mentioned it today.

 

[72 440 Barracuda]

Agreed. My stock Demon has an increase of around 27 MPH in great air, so 33 MPH increase at this time of year is huge.

I looked at my slip and I was 26mph gain on the top half - how do you calculate the HP from that - some HP calculator somewhere?

 

[Phast Hemi]

So on stock boost this is being achieved, I assume, by adding a considerable amount of ignition advance. I wonder at what point adding advance no loner produces results? I believe at some point things tip over? Seems quite a bit of overhead for advancing timing based on your results PH. I run Renegade race fuel and their tech director and I had a nice chat about fuel, timing, etc. He claims I can put as much timing in the car as it will make power on with this fuel, thus my curiosity.

Mine picked up 26mph on the back half on 93 in 3600 DA. Never really paid much attention till you mentioned it today.

Yes, this is a stock boost setup. These engines will take quite a bit of timing. The fuel used dictates how much timing it can take and at which timing it will make the most power. This is an advantage of e85 over any gasoline based fuel. Max timing is not always where the car will run the quickest... at least not on the hellcat and redyeye that I've had. Setting the car up for the back half is what allows a stock boost car to run down and , in many cases, drive around many of its pullied or nitrous assisted counterparts. The back half spread does shrink some in higher DA.

 

[Phast Hemi]

I looked at my slip and I was 26mph gain on the top half - how do you calculate the HP from that - some HP calculator somewhere?

I have found those HP calculators to be inaccurate at best.

 

[72 440 Barracuda]

I have found those HP calculators to be inaccurate at best.

I have used them a couple times - accuracy is kind of questionable, but does it get you in the ballpark ?- I think so - might be a big ballpark - but yeah its probably there... lol. Great for bench racing !!!!

 

[Speedy!]

The calcs are based on physics, perfect weather conditions, and perfect launch, no tire spin, etc. They're accurate "technically" but in the real world a lot more variables I think.

I use the ones over at Wallace Racing when I want a rough idea.

 

[Phast Hemi]

The calcs are based on physics, perfect weather conditions, and perfect launch, no tire spin, etc. They're accurate "technically" but in the real world a lot more variables I think.

I use the ones over at Wallace Racing when I want a rough idea.

Hey Speedy,

Run this through your calculator and tell us what comes up...

How much power does a car that weighs 4590 lbs with driver, runs 9.73 in the quarter or traps 144mph+ make?

This should be good... lol

 

[Speedy!]

You tell me - http://www.wallaceracing.com/et-hp-mph.php

 

[Jack_Toepfer]

Does the amount of timing the car will take also depend on the RPM it is being run at? The ceiling for RPM dictates the ceiling for timing, no?

And, FWIW, it's roughly 1000chp to run 144mph @ 4590lbs.
Is 200chp a lot of gain when you're running high octane at high rpm with a lot of timing? Yeah, but not unreasonable.

You don't go to a track to measure HP, the dyno is the only tool for that. Between dyno data and track data you can make correlations between the 2, but neither is a replacement for the other. Consider if there never was a dynamometer ... there would never be talk of HP, only elapsed time and MPH... and that would be fine too. Goals for making huge speed on the 2nd half of the track are goals for the track.

 

[Phast Hemi]

Does the amount of timing the car will take also depend on the RPM it is being run at? The ceiling for RPM dictates the ceiling for timing, no?

And, FWIW, it's roughly 1000chp to run 144mph @ 4590lbs.
Is 200chp a lot of gain when you're running high octane at high rpm with a lot of timing? Yeah, but not unreasonable.

You don't go to a track to measure HP, the dyno is the only tool for that. Between dyno data and track data you can make correlations between the 2, but neither is a replacement for the other. Consider if there never was a dynamometer ... there would never be talk of HP, only elapsed time and MPH... and that would be fine too. Goals for making huge speed on the 2nd half of the track are goals for the track.

The timing these engines will take depends more on the fuel used than the RPM. We are able to safely run the same timing on e85 through the engines power band. The timing we run is below the max timing the engine will take.

Regarding these calculators, when I type in 144 mph and 4590, it show s 1056 chp. That's over 250chp more than the same cars factory rating on 93. It's over 200 more than a demon rating (same engine) on the factory race gas tune. The factory race gas tune runs about 6 degrees more timing than the 93 tune and only produces about 40 more hp. Based on the theory that more timing could create all this power, you would need another 24- 30 degrees of timing on top of what is already there.

 

[Speedy!]

I think typical rule of thumb is 11 - 14HP per degree of timing, up to a point obviously. From the tuning information I've studied there will come a point when you add another degree but the engine doesn't make anymore power. This assumes a fuel that will NOT knock. Once this point is achieved, most tuning information suggests to remove 1 degree at that point.

This is just what I've studied. I've not had experience doing this personally (I'm scared LOL).

 

[Phast Hemi]

Does the amount of timing the car will take also depend on the RPM it is being run at? The ceiling for RPM dictates the ceiling for timing, no?

And, FWIW, it's roughly 1000chp to run 144mph @ 4590lbs.
Is 200chp a lot of gain when you're running high octane at high rpm with a lot of timing? Yeah, but not unreasonable.

You don't go to a track to measure HP, the dyno is the only tool for that. Between dyno data and track data you can make correlations between the 2, but neither is a replacement for the other. Consider if there never was a dynamometer ... there would never be talk of HP, only elapsed time and MPH... and that would be fine too. Goals for making huge speed on the 2nd half of the track are goals for the track.

Here is another calculation from the same site using 144mph, 4590lbs, 9.73 et. It has calculated both flywheel and rwhp. 962 rwhp on any stock boost car with any amount of timing at any rpm is hard to believe. Lots of pullied cars can't make that power.

Entering in the actual mph on the slip of 144.83 shows 979.45 rwhp. Either everyone else is artificially Inflating their power numbers to make their cars look good or this calculator is way off. Lol

 

[Phast Hemi]

I think typical rule of thumb is 11 - 14HP per degree of timing, up to a point obviously. From the tuning information I've studied there will come a point when you add another degree but the engine doesn't make anymore power. This assumes a fuel that will NOT knock. Once this point is achieved, most tuning information suggests to remove 1 degree at that point.

This is just what I've studied. I've not had experience doing this personally (I'm scared LOL).

Think your assessment about timing is close. You have the red-eye and demon spark tables in your possession as well so you know that the Demon HO spark tables run 5-6 degrees higher. Yet only 31 more hp in the demon for all that extra spark and a fuel change.

 

[Demon1]

Think your assessment about timing is close. You have the red-eye and demon spark tables in your possession as well so you know that the Demon HO spark tables run 5-6 degrees higher. Yet only 31 more hp in the demon for all that extra spark and a fuel change.

You are correct assuming the advertised HP numbers (808 & 840) are true numbers. I seem to remember guys that put their cars on a dyno were getting more than 32 HP increases, but my memory might be failing.

 

[Speedy!]

Think your assessment about timing is close. You have the red-eye and demon spark tables in your possession as well so you know that the Demon HO spark tables run 5-6 degrees higher. Yet only 31 more hp in the demon for all that extra spark and a fuel change.

You are correct assuming the advertised HP numbers (808 & 840) are true numbers. I seem to remember guys that put their cars on a dyno were getting more than 32 HP increases, but my memory might be failing.

Took the words outta my mouth. Kinda like how a RE only makes 797, yet the spark tables are identical to the Demon and I didn't see any other variable in the tune that would account for the difference in advertised power output.

I'll be playing with the new setup a lot here soon. I've already written three tunes that get progressively more aggressive down low in the timing table to see how the launches handle it. My upper RPM spark is based a lot on the Demon HO tune.

 

[Demon1]

Took the words outta my mouth. Kinda like how a RE only makes 797, yet the spark tables are identical to the Demon and I didn't see any other variable in the tune that would account for the difference in advertised power output.

I'll be playing with the new setup a lot here soon. I've already written three tunes that get progressively more aggressive down low in the timing table to see how the launches handle it. My upper RPM spark is based a lot on the Demon HO tune.

I've seen some say the difference between the Redeye's 797 and Demon's 808 base tune is related to lesser air flow from the scoop design differences. FCA may have even said it, but I call BS on that. I think it was more of a psychological ploy so us Demon guys wouldn't be upset. There may be a slight difference in cam design, but I don't see FCA limiting HP via a scoop design limitation.

 

[Speedy!]

Changes in airflow would certainly be more than an 11hp (1.4%) difference. Marketing if you ask me.

 

[BULL]

You guys understand the SAE engine-dyno setup, right?

And we know the block is the same...

Until someone can show me a specific difference in the base PCM, and counter the statement I got from XXXXX back when the RE was launched, I'm of the opinion that the 797/808 is a lie Marketing.

 

[Demon1]

Ha, three people in agreement must be a first.

 

[Phast Hemi]

Took the words outta my mouth. Kinda like how a RE only makes 797, yet the spark tables are identical to the Demon and I didn't see any other variable in the tune that would account for the difference in advertised power output.

I'll be playing with the new setup a lot here soon. I've already written three tunes that get progressively more aggressive down low in the timing table to see how the launches handle it. My upper RPM spark is based a lot on the Demon HO tune.

These are 2 different scenarios. On one hand you are comparing same engine, including same accessory drive. Pump vs race fuel. Kinda hard to understand only +31hp with +6d timing if the rule is 11-14hp per degree.

The other scenario compares the red-eye 797 to demon 808. Same engine and 93 tune. However, not the same accessory drive. Easier to comprehend how an additional load from accessories could rob 11 hp through parasitic losses.