80 MPH top speed

Shift to 2nd...

If I were you, with as many problems that you have, I would sell that machine for whatever I could get and go quickly in an other direction! There has not been another Slingshot made that is as bad as yours.

Quote from Tripod

Shift to 2nd...

After you shift into second gear, release the emergency brake to avoid a catastrophic situation.

What gear were you in? Was this the first time it has happened? When did you last nit experience the problem? What changes have be done since?

Uninstall the supercharger and install a turbo!!

Haven't heard of anyone else with this issue before. No clue.

Anything restricting the movement of the peddle on the driver's side floor or inside the engine bay?

The gas and brake peddles are close to each other. With my big foot and a heavy shoe on I have to be careful that my foot doesn't press on both the gas and brake peddle at the same time.

Quote from Bigdog

Took a 150 mile ride on the turnpike today...with the gas pedal mashed to the floor it barely hit 80...

Ease up on the gas and it picks up speed....

I’m open for possible causes...

Did it go any faster once you reached the TOP of the mountain?

Please do us all a favor and use the search function. This topic has been covered excessively since the beginning of the sling.
Hint: 5th gear = overdrive.
Top speed in 4th unless you have a lot of boost.

@Slingrazor - there hasn't been any mention of downshifting to fourth to gain mph.

He is indicating that he made more power / speed at 3/4 peddle vs pushing the peddle to the floor. He actually gained speed at 3/4 peddle - no mention of a downshift.

5th gear is an overdrive that will only pull if you have the power available. By pegging the throttle you bog the motor down in 5th. It is possible to hit 120 to 130 in 4th but at that speed if you shift to 5th your speed will deteriate.

Quote from Bigdog

In 5th gear on the flat. If I let up on the gas the speed would increase. Put with the pedal on the floor it would not go over 80. Now during the ride I hit 85 -90 But with 1/2 to 3/4 pedal not full pedal.

Any work on or near the CAI, O2 sensor, exhaust, header, etc?

I'm in 4th until 75 then 5th for cruise control

5th gear 75 80 tops with no wind. 4th gear 130 135 depending on wind conditions. 5th is overdrive this has been discussed 10 times.

Quote from Slingrazor

It is possible to hit 120 to 130 in 4th...

Ummm.... 132. Ish. I think. But pretty sure.

Find a good flat stretch of quiet desolate road and do peddal to the floor in 4th and do it in 5th I bet you a bag of the best gummies bears in the world you get 130 in 4th and 80 in 5th.

You hit the Rev limiter in 5th because of overdrive. So when you let off the gas in 5th it will Rev down to 80 because it's designed to just highway cruise. I'm Probley not explaining this correctly but I'm hoping you understand what I'm describing.