hey everybody, I just signed up. you have a great forum...very informative too. I have been lurking around as a guest for a couple days. lol

anyway, I just picked up an s13 coupe. unfortunately, its shit slow. the motor is the ka24e but its still damn fun on the mountain passes and will be sufficient for drifting while I'm still learning.

I am undecidied on which swap to go with. I initially wanted to go with the rb20. its cheap..fairly easy to install, 6cyl, and iron block..not to mention ihave 2 sitting in the warehouse. I have recently decided against it after speaking to a guy that has an rb25 in his vert. So...now...I'm thinking rb25.

here's my question..the rb25 is about 200lb lighter than the SR. I frequent the mountain passes a lot and understeer would most likely put me in a tree. do you think the understeer would be that bad with the heavier rb?

note: car will be used for drifting and road racing (circuit)

sorry if this post is so long.

jdmtrent wrote:here's my question..the rb25 is about 200lb lighter than the SR. I frequent the mountain passes a lot and understeer would most likely put me in a tree. do you think the understeer would be that bad with the heavier rb?

Welcome! If it were me I would sell the 240 and buy and RX7. J/K I would go with the RB25 if it were me. If I understand correctly the RB25 is lighter than the SR. This will create a better balance for handling but may not be the best for drifting where you want the back end to be lite. It would work great in the mountains and drifting where torque is king. I'm sure with proper suspension tuning either would work fine, but man the sound of those RBs! Almost as good as a rotary, almost.

darkducati wrote:Welcome! If it were me I would sell the 240 and buy and RX7. J/K I would go with the RB25 if it were me. If I understand correctly the RB25 is lighter than the SR. This will create a better balance for handling but may not be the best for drifting where you want the back end to be lite. It would work great in the mountains and drifting where torque is king. I'm sure with proper suspension tuning either would work fine, but man the sound of those RBs! Almost as good as a rotary, almost.

RB lighter than the SR? what form of physics do you work by?

jdmtrent wrote:..the rb25 is about 200lb lighter than the SR..

I was going off of his information. Thats why I said if I understand correctly. I don't know much of anything about Nissans because they don't make rotaries.

whoops.... SUGOI TYPO!!

*lighter = *heavier

sorry about that. but yeh, I really love the thought of a 6cyl iron block where I can keep the internals stock and run a good amount of power.

but I'm sure the susp can be tuned to dial out the understeer right? I hope it isn't so severe to where it will hinder the spirited mountain drives.

you can run good power out of the stock sr bottom end too.

well..I guess I'm really just asking if weight is really that big of an issue.

btw..thanks for all the help everyone.

less wheigh is like free hp