How about those ford cj's at vegas - Page 2

442OLDS · 10-31-2009, 08:18 AM

Quote:

Originally Posted by Superfan1

The AHFS is in effect if you run 1.40 or more under the sea level index. In Rd.1 of A/SA class eliminations, Brent Hajek ran 9.867 which is 1.433 under the 11.30 sea level index. Consequently, the hardtop, automatic CJs will get 14 HP on Monday (3.25% x 425HP); this will restrict them to AA/SA because their new factor will be 7.38. The hardtop, stick CJs got 14 HP after the Richmond National due to a run by Don Fezell.
Bill Seabrooks - superfan1
Bridgeport, Ct.

Will we be seeing more CONVERTIBLE Mustangs?

Chad Rhodes · 10-31-2009, 08:22 AM

Quote:

Originally Posted by Ken Kopecky

Since Vegas is an altitude factored track, would the AHFS be in effect? I thought that the AHFS was only used at the non-altitude corrected tracks. But what do I know, I think that the AHFS rules change every week.

Ken Kopecky
1454 E/SA

normally you would be right but they went 1.40 under the SEA LEVEL index

Steve Calabro · 10-31-2009, 08:24 AM

Kenny, 1.40 under the sea level index at any track is automatic HP.

11.30 index
-1.40
9.90 or below

Superfan1 · 10-31-2009, 08:34 AM

Quote:

Originally Posted by RULER

When they get there NHRA gift of 14HP on monday they will have to carry 112lbs more so they will only be about 3 to 4 tenths quicker than the best none C.J. car out there. These cars shouldn't be in stock they should be in super stock, you don't see any 68 darts or barracudas with race hemis running stock and thats because they weren't street legal cars just like these new factory race cars are, Wake-Up NHRA!!

They won't have to carry 112 lbs. more because they will only be legal for AA/S and AA/SA with their new factor of 7.38. They will only have to add weight to get to the 7.50 AA/S and AA/SA factor. In A/S and A/SA their class minimum weight was 3400lbs (8 x 425); now their class minimum will be 3293lbs (7.5 x 439). As I see it, the main effect will be that they will have to run off of the much tougher 10.90 AA/S and AA/SA index instead of the 11.25 A/S or the 11.30 A/SA indexes.
Bill Seabrooks - superfan1
Bridgeport, Ct.

Superfan1 · 10-31-2009, 08:45 AM

Quote:

Originally Posted by 442OLDS

Will we be seeing more CONVERTIBLE Mustangs?

After taking a second look at the Classification guide, at 425 HP the CJ convertible has a factor of 7.82. When the 14 HP is added, their factor will be 7.57, so they will still be a "natural" AA car; therefore the convertibles will still be able to move down to A/S or A/SA.
Bill Seabrooks - superfan1
Bridgeport, Ct.

Steve Hagberg · 10-31-2009, 09:53 AM

EVAN; Your comments on effect of altitude on a supercharged engines performance are correct, except that you forgot to mention the offsetting effect that helps to keep these cars faster at tracks such as Las Vegas. Since a blower takes HP to compress the ambient air, less dense air will lower the blower output pressure, but will also lower the Hp needed to compress it. The power needed to run a blower is significant, so the 'gain' from reduction in load is also significant.
Steve

Evan Smith · 10-31-2009, 10:22 AM

Steve,

Can I assume that you've measured the differences at different boost levels in order to report these findings? In theory you are right, but we are talking about small changes in boost level from good air to bad air. Probably 3-4 psi on the CJs from sea level to Vegas. The cost to drive the blower for that extra 3-4 psi is very, very small.

I've tested over 100 blower cars with all types of blowers over the years and while I've not measured crank hp, save for one time on a 1,200 hp engine, I can tell you the loss in power from adding a few pounds of boost is not a lot. In that case it took upwards of 250 hp to run the blower. I would guess a change in boost, even at that level, would have very little effect on overall power loss/gain. Again, in theory you are right, but in practice the gain/loss is not what you think.

Most blower engines are designed to run with boost pressure so even if you removed the blower it wouldn't give you a fair result on power because the engine would likely be inefficient with no boost.

Evan

countrypuppy4865 · 10-31-2009, 02:57 PM

I was just wondering if anyone else noted the increments on Don Fezell's CJ in Richmond. To compare go to http://www.nhra.com/livetiming/livetiming.aspx and click on Race Archives. Find Virginia NHRA Nationals and click results. Compare Friday's Q1 increments to Sunday's R2 increments. They are pretty amazing!

Stephen & Horace Johnson · 10-31-2009, 04:25 PM

Quote:

Originally Posted by BOB KIRKBRIDE

The new Cobra Jets need their own class...say AAA/S or A/FX (Sugested by another post) You could not add a realistic horsepower figure and still run stock class. That is why Robert Pond, for instance could never run two four barrel carbs EVEN THOUGH those cars came that way, so AA/S was created. I think they should not have weight added or horsepower, just let them race each other for class!! In Stock eliminator they would be like all the rest PUT A NUMBER ON THE WINDOW! Wouldn't that be simple and mainly FAIR to all the other stock racer that have worked their butts of to gain performance over many years. just my ..02 cents worth. Bob K.

robert pond can run the 2-4 setup!!

Stephen Johnson #2162
Horace Johnson #2167
SS/D 427 Ford Fairlane NHRA-IHRA

ROY · 10-31-2009, 04:40 PM

The guys complaining about horsepower numbers must be GM guys.Take a 375hp,396,same specs as a 425hp,396,soooooo.Think of the many hp factors for basically the same 350 chevy engine.NHRA has always facrored according to who makes the most noise and who is their biggest sponsor at that time! JMO,got out of "stock" in the 70's when it was getting stupid! ROY.

10-31-2009, 08:24 AM	#13
Steve Calabro Member Join Date: Jun 2007 Location: New Jersey Posts: 198 Likes: 225 Liked 43 Times in 12 Posts	Re: How about those ford cj's at vegas Kenny, 1.40 under the sea level index at any track is automatic HP. 11.30 index -1.40 9.90 or below __________________ Steve Calabro 1199 STK, SS

10-31-2009, 09:53 AM	#16
Steve Hagberg Junior Member Join Date: Dec 2007 Posts: 38 Likes: 0 Liked 0 Times in 0 Posts	Re: How about those ford cj's at vegas EVAN; Your comments on effect of altitude on a supercharged engines performance are correct, except that you forgot to mention the offsetting effect that helps to keep these cars faster at tracks such as Las Vegas. Since a blower takes HP to compress the ambient air, less dense air will lower the blower output pressure, but will also lower the Hp needed to compress it. The power needed to run a blower is significant, so the 'gain' from reduction in load is also significant. Steve Last edited by Steve Hagberg; 10-31-2009 at 10:11 AM. Reason: spelling

10-31-2009, 10:22 AM	#17
Evan Smith Member Join Date: Nov 2001 Location: Tampa Posts: 400 Likes: 7 Liked 115 Times in 5 Posts	Re: How about those ford cj's at vegas Steve, Can I assume that you've measured the differences at different boost levels in order to report these findings? In theory you are right, but we are talking about small changes in boost level from good air to bad air. Probably 3-4 psi on the CJs from sea level to Vegas. The cost to drive the blower for that extra 3-4 psi is very, very small. I've tested over 100 blower cars with all types of blowers over the years and while I've not measured crank hp, save for one time on a 1,200 hp engine, I can tell you the loss in power from adding a few pounds of boost is not a lot. In that case it took upwards of 250 hp to run the blower. I would guess a change in boost, even at that level, would have very little effect on overall power loss/gain. Again, in theory you are right, but in practice the gain/loss is not what you think. Most blower engines are designed to run with boost pressure so even if you removed the blower it wouldn't give you a fair result on power because the engine would likely be inefficient with no boost. Evan __________________ Evan Smith 1798 STK

10-31-2009, 02:57 PM	#18
countrypuppy4865 Senior Member Join Date: Nov 2003 Location: Donaldsonville, LA Posts: 980 Likes: 17 Liked 228 Times in 70 Posts	Re: How about those ford cj's at vegas I was just wondering if anyone else noted the increments on Don Fezell's CJ in Richmond. To compare go to http://www.nhra.com/livetiming/livetiming.aspx and click on Race Archives. Find Virginia NHRA Nationals and click results. Compare Friday's Q1 increments to Sunday's R2 increments. They are pretty amazing! __________________ Jimmy "Cooter" Hidalgo, Jr. 4865 E/SA '04 GTO 4865 SS/GA '99 Firebird

10-31-2009, 04:40 PM	#20
ROY Junior Member Join Date: Oct 2007 Posts: 15 Likes: 0 Liked 0 Times in 0 Posts	Re: How about those ford cj's at vegas The guys complaining about horsepower numbers must be GM guys.Take a 375hp,396,same specs as a 425hp,396,soooooo.Think of the many hp factors for basically the same 350 chevy engine.NHRA has always facrored according to who makes the most noise and who is their biggest sponsor at that time! JMO,got out of "stock" in the 70's when it was getting stupid! ROY.