My 302 based motor is 580 hp 7k rpm and 465 ftlbs 4.9k rpm on the dyno. So probably somewhere just south of 500hp at the rear wheels. One thing that is not an issue is traction. I run slicks, but more inportantly have tallish gearing in gears 1-3 because its a track setup and Tq is fairly high up the rev range. All of which is quite different to stock gearing and high tq low down the rev range on a 351/427
The key is learnign how to feed the power in on bends so as not to upset the balance more than traction being an issue, its not a throttle mash. The great part is this near unlimited reserve of go to feed in after the apex. On straights traction is simply not an issue, more of an issue is that straights with this hp become short and corners arrive real fast, the inclination then is to overbrake instead of carrying more speed to the apex.
The good part of a lot of power, the right gearing and a big power spread with lots of rev range is you dont have to shift a lot which costs time. The glenn is basicaly all 3rd and 4th gear.
If the motor was say a hydralic lifter with lower rev range and stock gearing maybe there would be 3 gears needed even though a 351/427 make more hp, so it could be slower.
So many varaibles. But if you are using a 302 motor its simply not going to put down enough tq low enough in the rev/spped range for straightline traction to be an issue, esp with track gearing.
Stock gearing with a 427 500ftbs + and over 550hp at lowish revs on street tires, yes traction could be an issue, as would gearbox life and halfshafts .
Want to go fast on track, add lightness, great springs/shocks and good brakes and a motor with a broad spread. Actualy the stock brakes are pretty good.
The biggest issue I have found is the car getting light at speeds of 140+ on bends, esp when the suspension unloads over even a mild rise, to a certain extent you can dial this out with a bit of rebound stiffness. Roll can also be an issue, swaybar adjustments mean prior shock settings no longer valid. My guess is lower power means you probably sort the suspension quicker and easier as the greater power can be used as a workaround and is another variable. There a re lots of varaibles to sort and understand to go fast in a Gt40.
Can the car handle 500 rwp, easily imo, but big hits of tq low down with short stock gearing as in a 427 could be an issue.
We seem to fixate on the mk2 at lemans. These were 4 speed boxes with really tall gearing to run lemans. Acceleration with the tall gearing was not spectacular, the goal was to run a low rev low stress motor for 24 hrs and acheive speed.
Look at performance stats for Mk1 Gt40s with even the later 425 ho 289s and things like 0-60 were what we would considder poor today, these cars often being geared for top end or at the very least a race track.
Today a higher hp motor with good revs and tq can get you great accelration as was found on setups in the 60s for shorter tracks while still maintaining higher top speeds due to extra hp at higher revs. In the 60s it was either accelration gearing or top end gearing, motors then being power/rev limited, modern motor setups can work around this.
Frankly 500rwp to me feels well within the chassis limits of the car.
A last note on weight, the 351 block is about 70lbs more than a 302, most of this excess weight is up top where you least need it. Your intake manifold will be heavier too, as will the crank conrods etc. So figure adding another 100-120+lbs to any 302 setup. On the street this may not be an issue at all. Hp is HP, but a 351 mtoor will make a lot more Tq and uaualy way lower down in the rev range, this will make accelration feel more epic, but can create traction issues too. Basicaly more than headline numbers it depends what motor/block you have, what gearing and tires you run.
The key is learnign how to feed the power in on bends so as not to upset the balance more than traction being an issue, its not a throttle mash. The great part is this near unlimited reserve of go to feed in after the apex. On straights traction is simply not an issue, more of an issue is that straights with this hp become short and corners arrive real fast, the inclination then is to overbrake instead of carrying more speed to the apex.
The good part of a lot of power, the right gearing and a big power spread with lots of rev range is you dont have to shift a lot which costs time. The glenn is basicaly all 3rd and 4th gear.
If the motor was say a hydralic lifter with lower rev range and stock gearing maybe there would be 3 gears needed even though a 351/427 make more hp, so it could be slower.
So many varaibles. But if you are using a 302 motor its simply not going to put down enough tq low enough in the rev/spped range for straightline traction to be an issue, esp with track gearing.
Stock gearing with a 427 500ftbs + and over 550hp at lowish revs on street tires, yes traction could be an issue, as would gearbox life and halfshafts .
Want to go fast on track, add lightness, great springs/shocks and good brakes and a motor with a broad spread. Actualy the stock brakes are pretty good.
The biggest issue I have found is the car getting light at speeds of 140+ on bends, esp when the suspension unloads over even a mild rise, to a certain extent you can dial this out with a bit of rebound stiffness. Roll can also be an issue, swaybar adjustments mean prior shock settings no longer valid. My guess is lower power means you probably sort the suspension quicker and easier as the greater power can be used as a workaround and is another variable. There a re lots of varaibles to sort and understand to go fast in a Gt40.
Can the car handle 500 rwp, easily imo, but big hits of tq low down with short stock gearing as in a 427 could be an issue.
We seem to fixate on the mk2 at lemans. These were 4 speed boxes with really tall gearing to run lemans. Acceleration with the tall gearing was not spectacular, the goal was to run a low rev low stress motor for 24 hrs and acheive speed.
Look at performance stats for Mk1 Gt40s with even the later 425 ho 289s and things like 0-60 were what we would considder poor today, these cars often being geared for top end or at the very least a race track.
Today a higher hp motor with good revs and tq can get you great accelration as was found on setups in the 60s for shorter tracks while still maintaining higher top speeds due to extra hp at higher revs. In the 60s it was either accelration gearing or top end gearing, motors then being power/rev limited, modern motor setups can work around this.
Frankly 500rwp to me feels well within the chassis limits of the car.
A last note on weight, the 351 block is about 70lbs more than a 302, most of this excess weight is up top where you least need it. Your intake manifold will be heavier too, as will the crank conrods etc. So figure adding another 100-120+lbs to any 302 setup. On the street this may not be an issue at all. Hp is HP, but a 351 mtoor will make a lot more Tq and uaualy way lower down in the rev range, this will make accelration feel more epic, but can create traction issues too. Basicaly more than headline numbers it depends what motor/block you have, what gearing and tires you run.
