Question for guys who actually have the the Roush Kit

[Jmtoast]

I am anxious to hear how the Nittos work for you. I think I am going with Mickey Thompson ET street SS in the 305/35r19 size but I haven't fully made up my mind yet. I am not sure whether to try my 26.1 inch tall 275/40r17s first or not.

I need to ask my tech more about the issue of a shift to 7th near the end of the quarter. I don't think it will hurt with HP in the mid 650s, especially if the trans is in good shape and the fluid level is where it belongs. I am sure I will get the taller tires at some point, though.

Shouldn't need taller tires to get in the 10's. Lot of GT500 guys are running 20" Toyo's, which is the parent company of Nitto and is basically the same compound, and getting into the 9's and low 10's (modded of course) with them.

 

[Stymee]

Even though I'll probably never run my car at a dragstrip, I'm following to see results from others. Question; Have you got the 3.55 or 3.15 rear gear?

I have 3:15’s running a Nitto NTO5R 27.4 tire, Should be perfect and I believe they should hook?

 

[brucelinc]

I have the 3.55 gear. I liked it when stock and my car would stay in 6th at the end of the quarter mile...around 120 MPH. With boost, I expect to reach a higher speed in the quarter and I may see a shift to 7th. Some people say that the 7th gear clutch is weak and it is bad to have the car shift to 7th at WOT with boost. Most people with boost prefer the 3.15 gear for drag racing.

Much will depend upon what RPM Roush has the shift points set at. Just using 7200 RPM as an example, with my 26.1 inch tires, it should shift to 7th at 123 MPH. I hope to see more speed than that in the quarter. With 27.4 inch tires, 7200 RPM would take me to 129 MPH in 6th. That should be sufficient to avoid 7th.

 

[Stymee]

I think the Roush does in fact shift at 7000, I would hope I see 127 at Atco when looking at 420’s MPH in AZ?

 

[brucelinc]

I think the Roush does in fact shift at 7000, I would hope I see 127 at Atco when looking at 420’s MPH in AZ?

With 93 octane fuel and running at Atco, you may see higher than that. The fuel and faster track should give better results than 420 had on 91 in AZ.

 

[Cory S]

These things usually need to shift between 7400-7600 for lowest ET. That’s sad if they shift at just 7200.

 

[Stymee]

These things usually need to shift between 7400-7600 for lowest ET. That’s sad if they shift at just 7200.

Remember this is a warranty tune, Revving the coyote up at 7500 could put stress on things, I’m not saying opg/cs will break but most shops want them once u start buzzing the Coyote 7500.

 

[brucelinc]

These things usually need to shift between 7400-7600 for lowest ET. That’s sad if they shift at just 7200.

I think that depends on where your HP and torque peaks are and the tuning typically determines that. There is no point in revving to where the power drops off. I also want to have max torque after the shift. The custom tuned Whipple guys like to rev them to the moon. I chose not to go in that direction.

 

[Stymee]

I think that depends on where your HP and torque peaks are and the tuning typically determines that. There is no point in revving to where the power drops off. I also want to have max torque after the shift. The custom tuned Whipple guys like to rev them to the moon. I chose not to go in that direction.

That’s accurate, very smart Bruce, Roush power goes away around 7100-7200 from looking at the graphs, so buzzing it high makes no sense

 

[Jmtoast]

That’s accurate, very smart Bruce, Roush power goes away around 7100-7200 from looking at the graphs, so buzzing it high makes no sense

I have a a Roush Speedometer and it maxes at 8000, redline starts at 6500 and shifts around 7. PBD I believed explained this in one of their videos when they talked about expanding it out in their tune and the difference it makes when at the strip.

 

[brucelinc]

There have been a few guys who had their tuner raise the shift points but it didn't help their strip performance. In stock and tuned form, my car shifted at 7400 and I thought that was about perfect when NA. With boost, there will be much stronger low end torque so it may not need to rev as high.

 

[Cory S]

That’s accurate, very smart Bruce, Roush power goes away around 7100-7200 from looking at the graphs, so buzzing it high makes no sense

Usually shifting about 300-400 over HP peak puts your recovery at peak TQ at around 5300-5500 RPM. Exactly where a 7200peak HP engine should be. Or close to it rather.

 

[brucelinc]

On this dyno sheet from the Facebook guy with phase 2, it appears that they went to 7200?

 

[WOTPULLS]

On this dyno sheet from the Facebook guy with phase 2, it appears that they went to 7200?

that could also be because of speed limiter kicking in, not sure what gear ratio they have.

 

[Old5.Oguy]

Getting the phase two tune installed Saturday. I’ll let you know what the numbers are. I made 573 RWHP with a phase one with the stock exhaust. I’ve since put on. Roush H pipe and Axle back. Still have the stock headers. Hoping for at least 600 RWHP.