Boost Drop at High RPM

[Autopart101]

I posted the wrong graph before....a Whipple 3.0 should hold (and increase slightly) boost until redline. Look at these two graphs as comparison

Are you 100% sure they are graphing boost in both of the ones you posted? This is why it's nice to see the whole graph (as well as the legend). If boost is going down you will be able to tell in the power curve.

Yes graphing boost. Same Dyno.
Roush E85 87mm TB

Whipple 3.0 132mm TB 93 pump

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[robvas]

That spiky shit in your HP at higher RPMs could indicate slip, which coincides with that dip after 55-6000

That red line in the first graph looks wonky too right in the middle

 

[Autopart101]

That spiky shit in your HP at higher RPMs could indicate slip, which coincides with that dip after 55-6000

That red line in the first graph looks wonky too right in the middle

The spikes are in both cars dyno graphs. Roush and Whipple. The wonky at crossover was tires spinning on the dyno at WOT.

 

[robvas]

The spikes are in both cars dyno graphs. Roush and Whipple. The wonky at crossover was tires spinning on the dyno at WOT.

Both belts could be slipping. That Whipple for sure should be building boost until redline. I can't find a Roush 2650 graph with boost logged

I would hit up the massive Roush thread:

https://www.mustang6g.com/forums/th...s-who-actually-have-the-the-roush-kit.127474/

 

[HKusp]

I agree with robvas, that Whipple car should be making steam up top, where the 2650 is running out of gas. Up top is where the Whipple REALLY shines.

 

[hlfbkd420]

Both belts could be slipping. That Whipple for sure should be building boost until redline. I can't find a Roush 2650 graph with boost logged

I would hit up the massive Roush thread:

https://www.mustang6g.com/forums/th...s-who-actually-have-the-the-roush-kit.127474/

From my understanding, the Roush kit will pull timing when the IAT2 temps are above 100 degrees (easy in my area) and further at 140 degrees. At 150ish degrees it starts to close the throttle blade. In my case, in the summer I am at 12lbs of boost until about the 1/8th mile and then the TB is closing gradually to taper the boost off. In the summer, the back half of a 1/4 mile run is about 24mph gain over my 1/8th mile MPH.. So if I am at 100mph at the 1/8th, I am at 125 in the quarter. In the winter, I am typically 30mph or more above my 1/8th mile MPH.. IE, 100 in the 1/8th, 130-135 in the quarter. The back half isn't typically where your great time comes from and in my case, I have run a 10.9@125 in the summer and a 10.9@135 in the winter as well. The back half times were very close though when I compared them. The cars best time is a 10.7@135 with a 1.8 second 60'.

If the car was heatsoaked on the dyno, the Roush will definitely be closing the TB and boost will be tapering down.

 

[Autopart101]

Both belts could be slipping. That Whipple for sure should be building boost until redline. I can't find a Roush 2650 graph with boost logged

I would hit up the massive Roush thread:

https://www.mustang6g.com/forums/th...s-who-actually-have-the-the-roush-kit.127474/

I agree with robvas, that Whipple car should be making steam up top, where the 2650 is running out of gas. Up top is where the Whipple REALLY shines.

680rwhp looks normal for a Whipple 3.0 stage 2 set up on pump gas. Maybe the boost ref isn't correct????

 

[Autopart101]

From my understanding, the Roush kit will pull timing when the IAT2 temps are above 100 degrees (easy in my area) and further at 140 degrees. At 150ish degrees it starts to close the throttle blade. In my case, in the summer I am at 12lbs of boost until about the 1/8th mile and then the TB is closing gradually to taper the boost off. In the summer, the back half of a 1/4 mile run is about 24mph gain over my 1/8th mile MPH.. So if I am at 100mph at the 1/8th, I am at 125 in the quarter. In the winter, I am typically 30mph or more above my 1/8th mile MPH.. IE, 100 in the 1/8th, 130-135 in the quarter. The back half isn't typically where your great time comes from and in my case, I have run a 10.9@125 in the summer and a 10.9@135 in the winter as well. The back half times were very close though when I compared them. The cars best time is a 10.7@135 with a 1.8 second 60'.

If the car was heatsoaked on the dyno, the Roush will definitely be closing the TB and boost will be tapering down.

The cold air was removed so we could see the TB blade during the runs. I thought the TB may be closing. It did not close. This is not the stock Roush tune as the cars on E85. Timing starts to be pulled at 140 degrees.

 

[hlfbkd420]

The cold air was removed so we could see the TB blade during the runs. I thought the TB may be closing. It did not close. This is not the stock Roush tune as the cars on E85. Timing starts to be pulled at 140 degrees.

Understood. Have you confirmed with Wengerd that he changes the actual temp at which it starts closing the TB? I think that is a fuction of the Roush tune and he starts with that as a base. I am on pump 91 and tuned by Wengerd as well and I know that mine will still close the TB when the temps get high. It starts small but by the end of the 1/4 my boost can be at 1.5lbs or lower.

Just noticed your Interchiller. I would assume IAT2's are not the issue then. Do you have a way to log the car on your own? Not just with the dyno, a laptop or OBD2 device for your phone. May allow further insight.

 

[robvas]

680rwhp looks normal for a Whipple 3.0 stage 2 set up on pump gas. Maybe the boost ref isn't correct????

How much boost was it making? can't see any numbers on the graph

The one I posted was 755/560 on ~11psi on pump gas on 93

https://www.fordmuscle.com/tech-sto...lethal-upgrade-from-whipple-to-over-755-rwhp/

 

[Autopart101]

Understood. Have you confirmed with Wengerd that he changes the actual temp at which it starts closing the TB? I think that is a fuction of the Roush tune and he starts with that as a base. I am on pump 91 and tuned by Wengerd as well and I know that mine will still close the TB when the temps get high. It starts small but by the end of the 1/4 my boost can be at 1.5lbs or lower.

Just noticed your Interchiller. I would assume IAT2's are not the issue then. Do you have a way to log the car on your own? Not just with the dyno, a laptop or OBD2 device for your phone. May allow further insight.

The dyno was before the interchiller. My first thoughts are the TB and inlet are to small. That's why I'm seeing a boost drop (we didn't see belt slip or the TB closing during pulls) Then I see a dyno sheet same dyno Whiple 3.0 132mm tb. I see the same boost drop....

 

[Autopart101]

How much boost was it making? can't see any numbers on the graph

The one I posted was 755/560 on ~11psi on pump gas on 93

https://www.fordmuscle.com/news/power-by-the-hours-jake-long-drops-a-blown-coyote-in-his-cobra/

Whipple starts ar 12 drops to 9.

 

[robvas]

Whipple starts ar 12 drops to 9.

It should be making similar power then, and it isn't.

There could be a hundred things wrong but it's most likely not the supercharger and not the 132mm throttle body (car in the article that made way more power had the same one)

 

[Autopart101]

It should be making similar power then, and it isn't.

There could be a hundred things wrong but it's most likely not the supercharger and not the 132mm throttle body (car in the article that made way more power had the same one)

Whats way more power on pump gas?? 680 sounds about right for pump gas.

 

[Autopart101]

How much boost was it making? can't see any numbers on the graph

The one I posted was 755/560 on ~11psi on pump gas on 93

https://www.fordmuscle.com/tech-sto...lethal-upgrade-from-whipple-to-over-755-rwhp/

755 on pump sounds abnormal

It should be making similar power then, and it isn't.

There could be a hundred things wrong but it's most likely not the supercharger and not the 132mm throttle body (car in the article that made way more power had the same one)

Understood. Have you confirmed with Wengerd that he changes the actual temp at which it starts closing the TB? I think that is a fuction of the Roush tune and he starts with that as a base. I am on pump 91 and tuned by Wengerd as well and I know that mine will still close the TB when the temps get high. It starts small but by the end of the 1/4 my boost can be at 1.5lbs or lower.


Just noticed your Interchiller. I would assume IAT2's are not the issue then. Do you have a way to log the car on your own? Not just with the dyno, a laptop or OBD2 device for your phone. May allow further insight.

Great point. I'll reach out to review the dyno logs.

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