ZX2 speed reduction

[Roadrunner]

Has anyone noticed a top speed reduction with the ZX2 rear suspension? I have an 06 apex rtx which i converted to a 136" with a ZX2. Was in Old Forge last weekend and was only able to get 112mph on the dream-o meter. Running a 1-1/1/4 preditor with 168 stud, excell exhaust, ulmer cool air kit, fuel controller with cr9ek plugs and ulmer clutch kit with 23 tooth top gear. with a machined primary to achieve proper belt clearance. Only revving 10500 rpm so i know im a bit off. Lake was snow crovered with lighty packed snow at best. What are you guys seeing for mph?

 

[Roadrunner]

P.S this is not a knock on Allen my sled hulls the mail up to the top end but seems flat after that. Yet to contact Allen just wanted to see what others have seen.

 

[ROCKERDAN]

Has anyone noticed a top speed reduction with the ZX2 rear suspension? I have an 06 apex rtx which i converted to a 136" with a ZX2. Was in Old Forge last weekend and was only able to get 112mph on the dream-o meter. Running a 1-1/1/4 preditor with 168 stud, excell exhaust, ulmer cool air kit, fuel controller with cr9ek plugs and ulmer clutch kit with 23 tooth top gear. with a machined primary to achieve proper belt clearance. Only revving 10500 rpm so i know im a bit off. Lake was snow crovered with lighty packed snow at best. What are you guys seeing for mph?

you are now running a 136 with taller skid and wonder why it goes slower?????.......what did you expect?...ofcourse its gonna go slower then a 121 with lower skidframe.

136 is for smoother ride not speed....121 is always gonna be faster,less rotation mass and smaller footprint.

Dan

 

[number1kyster]

When I geared my vector and installed an ulmer racing stage 3 clutch kit I lost about 5 MPH on top.

 

[mdkuni]

Speed loss here on my 121" Apex ER, I also switched skis though. I will need to do more testing to know for sure.

 

[Roadrunner]

One of the reason's im asking is because i can pull my friends attack on the bottom end but he is about 1mph faster than me on the top end. I did expect it to be a touch slower but didnt think i would get walked by a stocker. Do you think with the engine only spinning 10400-10500 rpm that im giving up much? Will the ignition module make much of a differance or is that more for midrange power?

 

[TurboTime]

One of the reason's im asking is because i can pull my friends attack on the bottom end but he is about 1mph faster than me on the top end. I did expect it to be a touch slower but didnt think i would get walked by a stocker. Do you think with the engine only spinning 10400-10500 rpm that im giving up much? Will the ignition module make much of a differance or is that more for midrange power?

The ignition module will make a little difference, a couple mph. Also with 168 studs, this will slow you down aprox 3-5 mph. Take a little weight off the tips on your clutch to run approx 10800 to 11000, should help.

But Dan is right, changing to 136 and a higher suspension will slow your top end. You gotta give to get.

GL,

Kevin