GEN 1 New Roush SC install - is this normal?

[Dane]

I got my Roush SC installed two weeks ago along with the upgraded pulley, throttle body, and JDM tune. I've noticed that from a stop, just foot on the brake, the sucker really wants to go now. It's noticeable. I kinda assume it's just the extra power since the idling speed seems normal. However, one thing of note, frequently, but not always, if I let off the gas, it chills for a second like "normal" used to be, but then it like, lurches forward and wants to go. It makes me wonder if it's the torque converter locking in or something? I'm kinda ignorant of automatic transmission guts, so that might be a dumb thought. Other times it doesn't have that "chill" moment and just goes like above. It's totally manageable, but also very noticeable, even towing a trailer. What is happening and is it just fine or something weird?

 

[jokerz]

Datalog it and send it to Jdm


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[JimIII@JDM]

Make sure you don't have any vacuum leaks, that would cause a high idle speed. Also what is the idle RPM speed? Which throttle body did you get the twin 65mm Ford racing? If so it might require a tweak to the set screw, call us before you do that though.

JimIII

 

[Dane]

Make sure you don't have any vacuum leaks, that would cause a high idle speed. Also what is the idle RPM speed? Which throttle body did you get the twin 65mm Ford racing? If so it might require a tweak to the set screw, call us before you do that though.

JimIII

The idle speed doesn't seem high, just powerful. I want to say it's something like 750ish? I'll check when I leave the office, but it's what I'd consider "normal", speedwise, from having the truck for four years. Yes, I went with that 65mm (Cobra Jet or something like that?) throttle body.

 

[JimIII@JDM]

The idle speed doesn't seem high, just powerful. I want to say it's something like 750ish? I'll check when I leave the office, but it's what I'd consider "normal", speedwise, from having the truck for four years. Yes, I went with that 65mm (Cobra Jet or something like that?) throttle body.

The truck will certainly have more pedal response with the bigger TB installed. A good test would be to put the stock GT500 TB back on and see the difference. Our tune offers more throttle response as well but we are targeting a more linear throttle pedal feeling to replicate what it would be like with a throttle cable. Basically a 1:1 ratio where as stock or with Roush tuning there is pedal delay built in.

 

[Dane]

The truck will certainly have more pedal response with the bigger TB installed. A good test would be to put the stock GT500 TB back on and see the difference. Our tune offers more throttle response as well but we are targeting a more linear throttle pedal feeling to replicate what it would be like with a throttle cable. Basically a 1:1 ratio where as stock or with Roush tuning there is pedal delay built in.

This is with your tune. The throttle response is awesome, but I'm talking about idling, just idling - foot on the brake. Maybe it's totally normal, but figured I'd check.