rb20det or sr20det
rb20det or sr20det
Prices are about the same but which one would be more fun and would the rb require different mounts etc? Which would be more fun?
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- Car: '92 240sx Convertible
'94 F-150 - Location: Fredericksburg, VA
if you do a search, this will have been covered many many times.
but i'll try and sum it up for you
the SR will bolt in directly and require very little to get it up and running.
The RB will require a bit more to get it in and going, but is ultimately another fairly straightforward swap. If you opt not to get a mount kit for the RB, it'll sit a bit forward. Underground Motorsports have RB swap mount kits you can purchase and I believe they do wiring service as well. You will also need to purchase a new driveshaft since the transmission will be in a different place than the KA (the SR requires no new driveshaft. the old KA shaft fits perfectly). Also, your suspension will NEED to be upgraded. The stock 240 suspension wasn't built to support an inline 6 and you'll go through your stock struts in no time.
The main issue between the two engines is that the RB weighs more than the SR and puts that weight out by the nose. The car will be a bit more sluggish feeling in turns, but will scream down the straightaways. An inline 6 is just naturally better for turbo applications than an inline 4 due to the increased number of exhaust pulses.
The SR will be a direct bolt in (you can use the old KA mounts if you wish, just pick the mounts that look in better condition). And since it weighs less, the car will feel more balanced. Even though it's an aluminum block, it's still a sturdy little engine, and under stock internals, will hold up to 400 RWHP.
Your definition of fun should dictate which engine you'd like more. The RB will be a great drag strip warrior, where as the SR will make for a better auto cross car. The only other issue to concern yourself with is the aftermarket. The SR has a vast aftermarket in the US, but the RB is just starting to gain speed and doesn't have the variety the SR has.
but i'll try and sum it up for you
the SR will bolt in directly and require very little to get it up and running.
The RB will require a bit more to get it in and going, but is ultimately another fairly straightforward swap. If you opt not to get a mount kit for the RB, it'll sit a bit forward. Underground Motorsports have RB swap mount kits you can purchase and I believe they do wiring service as well. You will also need to purchase a new driveshaft since the transmission will be in a different place than the KA (the SR requires no new driveshaft. the old KA shaft fits perfectly). Also, your suspension will NEED to be upgraded. The stock 240 suspension wasn't built to support an inline 6 and you'll go through your stock struts in no time.
The main issue between the two engines is that the RB weighs more than the SR and puts that weight out by the nose. The car will be a bit more sluggish feeling in turns, but will scream down the straightaways. An inline 6 is just naturally better for turbo applications than an inline 4 due to the increased number of exhaust pulses.
The SR will be a direct bolt in (you can use the old KA mounts if you wish, just pick the mounts that look in better condition). And since it weighs less, the car will feel more balanced. Even though it's an aluminum block, it's still a sturdy little engine, and under stock internals, will hold up to 400 RWHP.
Your definition of fun should dictate which engine you'd like more. The RB will be a great drag strip warrior, where as the SR will make for a better auto cross car. The only other issue to concern yourself with is the aftermarket. The SR has a vast aftermarket in the US, but the RB is just starting to gain speed and doesn't have the variety the SR has.
Just clearing up a couple things for our resident SR fanboi. 
A manual KA driveshaft will work fine with an RB20 but it does unfortunately weight a bit more (<100lbs) than your KA. As for aftermarket, the SR support is indeed a bit more widespread because (thankfully), the bandwagon hasn't hit the RB...yet. =\ (Though, the mere existence of your post provides a sturdy counter-argument...) Both are very strong and capable engines, and just go SR. 
A manual KA driveshaft will work fine with an RB20 but it does unfortunately weight a bit more (<100lbs) than your KA. As for aftermarket, the SR support is indeed a bit more widespread because (thankfully), the bandwagon hasn't hit the RB...yet. =\ (Though, the mere existence of your post provides a sturdy counter-argument...) Both are very strong and capable engines, and just go SR.