looks like the truck is finally ready
12-12-2018, 04:42 PM
#12
Stock GT500
We talked about a throttle body switch, however it was suggested that there are other/better places to spend money at this point. Matt and Tim both said their experience with throttle bodies on their dyno suggests the stock gt500 throttle body is good to at least 700rwhp before it becomes a restriction. Not to argue with anyone here on the forum, but these guys have been at it for a long time, so I went with their input. I"ll attach the dyno sheet in the next post so I don't lose all my text like I did in the first post.
The headers picked up 35rwhp and torque across the board. Preliminary numbers were 455/475. The final numbers are on the graph.
We talked about a throttle body switch, however it was suggested that there are other/better places to spend money at this point. Matt and Tim both said their experience with throttle bodies on their dyno suggests the stock gt500 throttle body is good to at least 700rwhp before it becomes a restriction. Not to argue with anyone here on the forum, but these guys have been at it for a long time, so I went with their input. I"ll attach the dyno sheet in the next post so I don't lose all my text like I did in the first post.
The headers picked up 35rwhp and torque across the board. Preliminary numbers were 455/475. The final numbers are on the graph.
That said, I think you have enough power to reach your goals and I imagine you'll tickle 11's now. I have an inkling that Dyno you are using is reading a bit low, as 500whp with full headers and a 75mm pulley on a custom tune makes no sense, even on a Roush 2300. The only other explanation is ****ty tuning, so if it doesn't run 11 something now, find a new tuner................and a throttle body :p
12-12-2018, 04:57 PM
#13
Originally Posted by BadCon
I disagree with the 700whp statement, as the GT500 throttle body is a restriction at pretty much any power level just based on the way positive displacement blowers work. You want the least amount of intake restriction possible, and I don't care if you are only making 400whp, a PD blower will always benefit from less intake restriction. Actual GT 500 mustangs typically get 30-40whp from a larger throttle body and a new intake elbow at or near stock boost levels. I'm not saying you'd see 40whp, but I'd be willing to bet you'd see 20whp at least, and for $550 its not a bad return for the dollar. The biggest difference between the VMP and Roush kits is the throttle body and elbow, and those kits, pulley for pulley, usually net about 50whp more when compared (custom tune to custom tune).
I have an inkling that Dyno you are using is reading a bit low, as 500whp with full headers and a 75mm pulley on a custom tune makes no sense, even on a Roush 2300. The only other explanation is ****ty tuning, so if it doesn't run 11 something now, find a new tuner................and a throttle body :p
I have an inkling that Dyno you are using is reading a bit low, as 500whp with full headers and a 75mm pulley on a custom tune makes no sense, even on a Roush 2300. The only other explanation is ****ty tuning, so if it doesn't run 11 something now, find a new tuner................and a throttle body :p
12-12-2018, 05:03 PM
#14
12-12-2018, 05:03 PM
#15
Senior Member
Thread Starter
I disagree with the 700whp statement, as the GT500 throttle body is a restriction at pretty much any power level just based on the way positive displacement blowers work. You want the least amount of intake restriction possible, and I don't care if you are only making 400whp, a PD blower will always benefit from less intake restriction. Actual GT 500 mustangs typically get 30-40whp from a larger throttle body and a new intake elbow at or near stock boost levels. I'm not saying you'd see 40whp, but I'd be willing to bet you'd see 20whp at least, and for $550 its not a bad return for the dollar. The biggest difference between the VMP and Roush kits is the throttle body and elbow, and those kits, pulley for pulley, usually net about 50whp more when compared (custom tune to custom tune).
That said, I think you have enough power to reach your goals and I imagine you'll tickle 11's now. I have an inkling that Dyno you are using is reading a bit low, as 500whp with full headers and a 75mm pulley on a custom tune makes no sense, even on a Roush 2300. The only other explanation is ****ty tuning, so if it doesn't run 11 something now, find a new tuner................and a throttle body :p
That said, I think you have enough power to reach your goals and I imagine you'll tickle 11's now. I have an inkling that Dyno you are using is reading a bit low, as 500whp with full headers and a 75mm pulley on a custom tune makes no sense, even on a Roush 2300. The only other explanation is ****ty tuning, so if it doesn't run 11 something now, find a new tuner................and a throttle body :p
I've spent a lot of money in the past few months....wheels and tires, gears, headers, pulley, tune, and now I'm ordering the taller tires as it's apparent the MT 3574's are ok, but they're a little short for as fast as the motor spins up in first gear. Traction is paramount. If it spins, it won't shift in time, period. The early 6 speeds shift based on vehicle speed instead of output shaft speed, so the shifting is delayed when there's a lot of wheel spin because speed is too low. Apparently the front wheels play a role in this also regarding sensing vehicle speed.
In short, if it hooks up, it will shift. It doesn't really make any difference what gears are in it if the tires aren't spinning, it will shift.
12-12-2018, 05:11 PM
#17
I thought your truck was 4x4? Geez, I really haven’t been paying attention.
With some drag radials I think you are there. But get it on the track before you spend anymore money lol.
With some drag radials I think you are there. But get it on the track before you spend anymore money lol.
12-12-2018, 05:32 PM
#18
Senior Member
Thread Starter
I already had the bias ply mickey's 28x11.5x17 and they dead hooked at the track, even with very little to no burn out. They turned in a 1.85 60'. I'm making a little more power now and have lower gears, but the taller tires I believe will help fight against wheel spin and help the truck roll out more before it needs to shift.
it did a 1.79 60' on the dyno with the short drag tires and 373 gears. they put the street tires on it with the 410's and it did a1.52 60' time. Hence the decision to opt for a taller tire. I'm pretty happy with everything so far. They've offered to go to the track with me and do some datalogging in order to dial in the transmission in case there's any problems left over. They learned a lot working on my truck, lol.
12-12-2018, 06:32 PM
#20
Senior Member
Thread Starter