Alright same S5 im looking at in my other posts. When I test drove it my dad commented that the engine didnt feel as smooth as an RX-3 that he drove a long time ago. Personaly, to me, it didnt feel as smooth as an FDs motor. So is this normal?

 

What did your dad mean by the smoothness? did the car hesitate when going on the gas? how did it not feel as smooth as a fd's motor to you? you really have to describe how it felt to see if its normal or something is wrong.

-Andrew

 

I mean as in how smoothly it accelerated, like a 4 cylinder vs a 6 cylinder, he said the FC felt like a 4 cylinder while the RX3 felt like a 6.

To me an FD feels like this this smooth force pushing you ahead, while a 4 cylinder vibrates around more, like the combustion strokes are more pronounced.

So I guess thats what im hitting at, it felt like the combustion strokes were more pronounced then in an FD.

 

bump for the sake of an answer....

 

Really damn hard to get an answer with such a personal description.

Do you mean smooth as in combustion, like steady firing, and this engine seemed to missfire or feel rugged when accelerating? Did you check compression?

 

It definatly wasent missfiring it was just a roughness, like the engine transmitted more vibration into the car then in an FD. Do FCs vibrate more?

Im gonna get a comp check done on tuesday.

 

i own an FC, and have for exactly a month now, you should feel almost no vibration from the engine, i notice a little shake around 1500rpm or so when the revs are dieing down, thats it....

 

well FC's are older cars and the bushings and engine/tranny mounts are probably more worn out causing more vibration. Could be as simple as that but I dont think anybody could say for sure unless they see the car for themselves. Hope that helps a little.

 

compression check goes differently for rotary motors. if the motor starts right up w/ 1 or 2 cranks, the motor is fine; which suggests the fact that the apex seals are still good. if that is the case, you won't need a compression check.

it could be just the ignition system.

 

I've been told by a few people here that it takes about 2 sometimes 3 seconds of cranking before the FC starts, and that this is normal. My car is like this.
If its all out roughness, it could be a shitty tps, you should look at the guide in the faq for buying an fc, there are some neato tests that you can do to determin problems.

 

It was hot at the time but it fired up right away. 2 cranks. I'll go look at the guides again.

 

the only time i see vibration in my FC3C is inbetween idel and 1,700 and from what i under stand that is normal

pretty mutch if i am going 45 in 5th grae witch puts me at about 1,500 rpm's there is a little vibration my shifter vibrates a little but thats because i need to replace the bushings due to agressive shifting

 

Mako, having both an FD, my 2nd FC and in the past 4 banger probe and a V6 probe and MX-6, I know what you're getting at. Yes there is a slight difference in the feel of the motors. FC rotors are heavier than FD rotors and produce a bit more centrifugal force. Compared to a reciprocating engine though, it should still feel very smooth. The motor in the RX-3 may have felt smoother due to less weight that the motor had to push however, its also possible that the FC's motor may be down on power. I think a compression check would be a good idea to let you know the condition of the motor atleast but overall... the FC is the heaviest RX-7 and the N/A flavor would have the lowest power to weight ratio. That may be what you're feeling.