Dyno - Should I use Raised Shift Points?

[Johnnyvav]

The Florida LX Club had our anniversary meet at Macedo Motorsports yesterday. Almost all that attended had dyno pulls. Most 5.7L's with any combination of exhaust mods seemed to put high 290's HP to the ground. Interesting enough, the three of us with high flow cats had the highest HP pulls for the 5.7L. RWHP 314, 309 & 304HP. The other two had superior hi flow cats than my crappy Mopars, but they still seemed to help over stock cats.

After looking at the HP & TQ curves, does it make sense to use the raised shift points on the SC Flashpaq?

Tq peeks around 4.6 RPM & HP around 5.3 RPM

[formerice]

It's hard to say other than trying it both ways at the track. Probably will slightly because when it shifts , it will put you higher up in the powerband of the next gear. If you have a Mustang Dyno available you can run quarter mile sprints right on the dyno and compare. Be forewarned Mustangs are more concervative as to hp ratings, you will probably see at least 20 less hp, but quarter mile times are very accurate if the data plugged in is correct. One varriable, on a dyno you are strapped down to the roller, so that can skew the results if you spin a lot on launch.

[BurntOrange]

Me and terry kicked that around a bit comparing everyones dyno sheets. Even the dynatech (spelling?) guys lost power after 5400-5500 rpms. So it seems that the rasied shift points would be good at the track so that you drop in the next gear high in the rpm range besides that it seems that the 5800 limit is good until we start superchargering and running cams. Just a few things we talked about after you left.

[InferAl]

Why would you think the others were superior and yours were crappy because of a dyno. The way dynos are you could go back tomorrow and you could be high and they could be low, there are so many variables engine temp, the person driving the car, the gas you put in your car. also milage on our dyno day the high milage cars were way higher than the exact same car with low milage. And the plain fact some cars are just faster than others for no reason accept they are

[Johnnyvav]

Why would you think the others were superior and yours were crappy because of a dyno. The way dynos are you could go back tomorrow and you could be high and they could be low, there are so many variables engine temp, the person driving the car, the gas you put in your car. also milage on our dyno day the high milage cars were way higher than the exact same car with low milage. And the plain fact some cars are just faster than others for no reason accept they are

The mopar cats are crappy, not because of the dyno. Here is the best explanation I've seen as to why Mopar Headers & FF cats tend to produce less HP on the dyno than many other brands:

Here's what engine builder, quarter-mile world record holder, and DR heads sales agent "FastMatt" Matt Monett told MEISTER when HE reported HIS dyno results from MFO5:

"...at 330 RWHP your car is still 16hp shy from what PRDave's Charger dynoed with the same heads/cam, also on a DynoJet. A lot of things can account for this, but on the top of my list would be the Mopar headers, Despite that Mopar calls them Full-length headers, they are not what I would call Full Length - at best they are "mid-length" headers. Next, the cats they use are "brick" cats similar to cats sold by exhaust shops under the name cat-co. Cats such as these are far inferior IMO to the super high flow all-metal cats that Dynatech uses."

AS REPORTED BY MEISTER:
CELs & codes: Mopar touts no codes or CELs. Correct, until cats are broken by road damage and exhaust collector threads are stripped by warping flanges. Though not a recommended practice, one occasionally bounces over something they should have avoided. For me it was a low curb at the immediate entrance of a walled parking lot. With my attention on the vehicles I was following I turned in too soon and transited the curb, smacking the lower front of each cat in the process. Had these been stainless steel cats it would have been had no problem whatsoever. However, knowing these cats were ceramic I resigned myself to my fate - these cats were doomed and would need to be replaced, sooner than later.

Sure enough, the inevitable CEL and codes came a thousand miles later, then repeated again in 150 miles. By this time I'd located some tougher stainless steel HF cats, and had them installed next day. With the new cats welded in place it was time to check for exhaust leaks. The right collector had a nasty exhaust leak shooting upward against the underbody, a worst-case scenario. The left collector had a slight leak, again at the upper surface. After a several-hour battle we got the collector fittings to not leak, on both sides. Permatex high temp silicone was required to gunk up the new fiber gaskets though to stop the leakage.

Major warpage occurs with the soft iron that whoever makes the Mopars uses. When bolts are tightened to stop the inevitable leaks, threads strip easily. Drilling out the threads and using a new bolt with nut was required on the right-side collector flange. The Dynatechs are stainless steel throughout and should be virtually free of both issues.


http://www.300cforums.com/forums/per...tml#post315009

I know you can't believe everything you read but FastMatt, Meister, and the DYNO have confirmned
what I have read.

[InferAl]

The mopar cats are crappy, not because of the dyno. Here is the best explanation I've seen as to why Mopar Headers & FF cats tend to produce less HP on the dyno than many other brands:

Here's what engine builder, quarter-mile world record holder, and DR heads sales agent "FastMatt" Matt Monett told MEISTER when HE reported HIS dyno results from MFO5:

"...at 330 RWHP your car is still 16hp shy from what PRDave's Charger dynoed with the same heads/cam, also on a DynoJet. A lot of things can account for this, but on the top of my list would be the Mopar headers, Despite that Mopar calls them Full-length headers, they are not what I would call Full Length - at best they are "mid-length" headers. Next, the cats they use are "brick" cats similar to cats sold by exhaust shops under the name cat-co. Cats such as these are far inferior IMO to the super high flow all-metal cats that Dynatech uses."

AS REPORTED BY MEISTER:
CELs & codes: Mopar touts no codes or CELs. Correct, until cats are broken by road damage and exhaust collector threads are stripped by warping flanges. Though not a recommended practice, one occasionally bounces over something they should have avoided. For me it was a low curb at the immediate entrance of a walled parking lot. With my attention on the vehicles I was following I turned in too soon and transited the curb, smacking the lower front of each cat in the process. Had these been stainless steel cats it would have been had no problem whatsoever. However, knowing these cats were ceramic I resigned myself to my fate - these cats were doomed and would need to be replaced, sooner than later.

Sure enough, the inevitable CEL and codes came a thousand miles later, then repeated again in 150 miles. By this time I'd located some tougher stainless steel HF cats, and had them installed next day. With the new cats welded in place it was time to check for exhaust leaks. The right collector had a nasty exhaust leak shooting upward against the underbody, a worst-case scenario. The left collector had a slight leak, again at the upper surface. After a several-hour battle we got the collector fittings to not leak, on both sides. Permatex high temp silicone was required to gunk up the new fiber gaskets though to stop the leakage.

Major warpage occurs with the soft iron that whoever makes the Mopars uses. When bolts are tightened to stop the inevitable leaks, threads strip easily. Drilling out the threads and using a new bolt with nut was required on the right-side collector flange. The Dynatechs are stainless steel throughout and should be virtually free of both issues.


http://www.300cforums.com/forums/per...tml#post315009

I know you can't believe everything you read but FastMatt, Meister, and the DYNO have confirmned
what I have read.

Well FastMatt and Miester just switched out the Dynatech for Kooks so I guess Dynatechs aren't any good anymore either

[DeafCharger]

Well FastMatt and Miester just switched out the Dynatech for Kooks so I guess Dynatechs aren't any good anymore either

Actually, Meister had Mopar long tubes before switched to Kooks.

[InferAl]

Actually, Meister had Mopar long tubes before switched to Kooks.

I didn't know that I just read this by Fast Matt he must have made a mistake

Quote:Fast Matt

And for the people that I know are going to ask, YES the dyno shop did still have on file our heads/cam Charger with the 268 cam on file so I got him to over lay them on the same chart for a comparison. It dynoed 367.7 HP and 383.7 TQ BUT remember this is with a few other things different from Meister's car also. Like Super chips tune vs more aggressive B&G tune, Dynatech headers VS Kooks, Crappy K&N CAI VS a Air Hammer, stock pulley vs ATI pulley.

[bradkaye]

After looking at the HP & TQ curves, does it make sense to use the raised shift points on the SC Flashpaq?

Beyond the question of if you want to run the higher shift points because of horsepower drop, there's a problem with drivability when using the raised shift points as well to consider that I've posted a question about on the Flashpaq forums

Kinda a dealbreaker for me. I'd like to run the higher points just to have a 400rpm cushion to not hit the rev-limiter when manually shifting.

[Johnnyvav]

I didn't know that I just read this by Fast Matt he must have made a mistake

Quote:Fast Matt

And for the people that I know are going to ask, YES the dyno shop did still have on file our heads/cam Charger with the 268 cam on file so I got him to over lay them on the same chart for a comparison. It dynoed 367.7 HP and 383.7 TQ BUT remember this is with a few other things different from Meister's car also. Like Super chips tune vs more aggressive B&G tune, Dynatech headers VS Kooks, Crappy K&N CAI VS a Air Hammer, stock pulley vs ATI pulley.

I think Fast Matt was referring to his test charger verse Meisters 300c:

Fast Matt
Superchips
Dynatech Headers
Crappy K&N CAI
Stock Pulley

Meister
B&G
Kooks Headers
Air Hammer
ATI Pulley

[Johnnyvav]

Beyond the question of if you want to run the higher shift points because of horsepower drop, there's a problem with drivability when using the raised shift points as well to consider that I've posted a question about on the Flashpaq forums

Kinda a dealbreaker for me. I'd like to run the higher points just to have a 400rpm cushion to not hit the rev-limiter when manually shifting.

Interesting, I program mine with AutoKick and don't use the auto stick too much. I also have the TSB 18-031-05 and believe it may help in the everyday drivability.

I did have an interesting conversation with Fixer last night. He mentioned it is a good idea to have the shift points set so that when the car shifts to the next gear it will hit the peak level of either the torque or horsepower. I tried this tonight and found that (with raised shift points) the RPM would kick back to about 4300 RPM in the next gear. Just a couple of hundred RPM below peek torque. If using this theory it seems that the raised shift points would be the optimal choice.

[MikeEast]

If you look at how the curve starts falling away, would it not make more sense to short-shift it? I mean like bumping the shifter around 4.5-5K?

I don't see any reason (yet?) to spin this motor up to 6250 rpm, it looks to me like it would be cooler to keep it under 5800 where it makes the most power. It sounds real nice and all, howling like like a lovesick banshee on a moonlit night, but I've not noticed any dramatic gains at the track in doing so.

If I'm wrong I'd love to hear the reasons.

Mike

[moparman53]

Mine hits the rev limits at around 5500 either way. Maybe I should try them raised again. I'm at normal now.

[Johnnyvav]

MikeEast- Here is my new theory.

Lets assume you shift around 5800 RPM. At 5800 RPM (according to your Dyno) you are putting down about 290 RWHP. When the car shifts gear you will probably go from about 5800 RPM to about 4000 RPM. At 4000 RPM you are putting down about 260 RWHP. So at 5800 RPM you still have more Horsepower than when you shift gears and start the next gear at 4000 RPM.

The earlier you shift, the lower RPMs & less HP you will have in the next gear until it revs up. Thus the 290 HP at 5800 RPM (although it is less than the peak) is better than the 260 HP when you shift gears.

I guess the goal would be to have your RPM close to the same HP when leaving one gear (on the decline of the HP Curve) and starting the next gear (on the incline of the HP Curve).

Again this is just a theory of mine & I am perfectly fine with being proved wrong or right!