PDA

View Full Version : RB25DET Modification Questions.


xnissan240sx
02-05-2012, 06:05 PM
I am looking to do some work to my RB25 before the season starts. I have gotten all the bearings, new rings, new springs, Gaskets, seals, N1 oil pump, water pump, timing belt, idlers, and Greddy intake. That's the list I got this year but I am wondering what would be some good upgrades to do to add some more power. By the upgrades I mean without putting in new cams, crank, and pistons. Next year I will be building it completely. I am basically wondering what RB25 guys like to do with stock internals, to get a decent amount of HP out of the motor, while still being in the safe HP range on the stock internals. The motor is going in a purpose built track car, and the HP I would like to achieve would be in the 350-400HP range. Any help would be awesome from some experienced RB owners.

Thanks!

ch1873857
02-05-2012, 06:29 PM
why not do cams? tomei lowered there prices and a set of cams can be had for 550 bucks. frsport.com. they take only an hour or two to do too.

turbociv910
02-05-2012, 06:30 PM
Kinda obvious question, to lazy to open the motor? Then...bigger turbo more boost and tune

P-Funk alot
02-05-2012, 06:35 PM
for that hp range all you really need is more fuel, boost and a good tune.

xnissan240sx
02-05-2012, 06:40 PM
why not do cams? tomei lowered there prices and a set of cams can be had for 550 bucks. frsport.com. they take only an hour or two to do too.
That still isnt out of the question. The only thing is I do have a budget and for this year I would rather just do the bolt ons right now and then next year when I have the money to completely build the motor I will be doing that. Basically looking to get some quick HP out of the stock motor this year, so I can save up.
Kinda obvious question, to lazy to open the motor? Then...bigger turbo more boost and tune
I already have the motor open, why do you think I would have the bearings, valve springs, ETC.
for that hp range all you really need is more fuel, boost and a good tune.
Yeah that's what I have herd from a few people say. Any idea on turbos? I am planning on doing 700cc injectors.

Darius
02-05-2012, 07:12 PM
If you are only going for 400 hp, then cams won't help you. Shifting your power band higher on a hydraulic lifter engine isn't necessary or beneficial for your application.

Stick with the things you are doing to freshen up the engine and keep the pistons stock.

89JDM240sx
02-05-2012, 07:22 PM
Just refresh the motor and use the parts you have... Use the stock throttle body with the IM dont use the Q45....

You can try n find a GT28RS turbo and increase your boost levels or a GT3071r...

And lastly get yourself a good EMS! And tune away

xnissan240sx
02-05-2012, 07:27 PM
Just refresh the motor and use the parts you have... Use the stock throttle body with the IM dont use the Q45....

You can try n find a GT28RS turbo and increase your boost levels or a GT3071r...

And lastly get yourself a good EMS! And tune away

Why don't go with the q45 TB? I am curious. And yes I have been looking for an EMS.

89JDM240sx
02-05-2012, 07:33 PM
Unless your running a larger turbo a q45 will give you a loss in bottom end torque...

Also the best EMS IMO is the Haltech platinum Pro... It plug in play

Kingtal0n
02-06-2012, 02:13 PM
You could focus more on the vehicle... lighter wheels, driveshaft, trunk etc... reduce the weight and air drag in any way possible.

Darius
02-06-2012, 02:31 PM
I agree, skip the Q45 TB. And I'd go with a 3071R-sized turbo (or similar).

I will cut you an amazing deal on my Power FC and save you $1000. What you'll be doing with the car won't justify a $2,500 haltech EMS. The PFC will do everything you need. PM me.

Functiontheory
02-06-2012, 02:47 PM
have you actually driven an rb25 swapped 240? its pretty good right out of the box. i have s2 rb25, mckinney mounts/ alluminum drive shaft, fmic, PSM cobra dp, isis shot gun straight through 3 inch no cat, rb20 wastegate ( since it boosts stock at 10lbs) act 6 puck unsprung clutch, and everything else is stock. and it drifts just fine and im running 17x10 wheels all around. i think you will be more then happy with just the stock set up now for now. and i agree with kingtalon you should upgrade suspension and steering. get good coilovers, knuckles, rack spacers, links, seat, roll cage. your stock rb will get you though the season just fine.

xnissan240sx
02-06-2012, 05:49 PM
have you actually driven an rb25 swapped 240? its pretty good right out of the box. i have s2 rb25, mckinney mounts/ alluminum drive shaft, fmic, PSM cobra dp, isis shot gun straight through 3 inch no cat, rb20 wastegate ( since it boosts stock at 10lbs) act 6 puck unsprung clutch, and everything else is stock. and it drifts just fine and im running 17x10 wheels all around. i think you will be more then happy with just the stock set up now for now. and i agree with kingtalon you should upgrade suspension and steering. get good coilovers, knuckles, rack spacers, links, seat, roll cage. your stock rb will get you though the season just fine.
I have driven in a car with an RB25 the skyline that the motor is coming from use to be mine so yeah I know the pick up the car has, just want more power for drifting. The car already has the cage, and I had bought all new PBM arms for front and rear as well as PBM coils, so my suspension is nothing to worry about, also picked up the super angle kit from PBM, have two OMP racing seals and harnesses, so the motor is the last thing I really have to do if anything. I still have money left over in my budget so i figured since I don't have enough to completely rebuild the motor this year, I will just get some bolt ons.
You could focus more on the vehicle... lighter wheels, driveshaft, trunk etc... reduce the weight and air drag in any way possible.
Like I said before the car is a purpose built track car. Has gram lights on, aluminium drive shaft, no interior, all harnesses cut down to bare minimum, and all the windows are 1/8" thick plexiglass. If you know of any other way to make the car even lighter please let me know. I am not about to buy carbon fibre because lets face it, it's a drift car and its going to get smashed.

Kingtal0n
02-06-2012, 06:12 PM
how about you shorten the intercooler plumbing?

ch1873857
02-06-2012, 09:55 PM
im with this guy ^

the best thing i liked about my previous 25 was the response. response trumps power in a lot of cases. nothing like trying to drift a car with excessive turbo lag... clutch kick clutch kick clutch kick...