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yoshiii335

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Posts posted by yoshiii335

    The rb20 and rb25

    in Forced Induction Performance

    Posted

    The rb20 and rb25

    Hello,

    I found some info from testing done on the r32 gtst and the r33 gtst.

    Its often said seemingly on websites that the rb20 is a motor lacking torque under 3000 rpm and that the rb25 is better, stock vs stock.

    I know that the rb25 is a more powerful motor and has more torque stock vs stock rb20.

    But in these test I found, it seems that the rb20 in a r32 gtst stock compared to a rb25 in a stock r33 gtst is not that bad.

     

    RB20.jpg

    RB25.jpg

    Questions about diffs

    in Drivetrain and transmission

    Posted · Edited by yoshiii335

    56 minutes ago, GTSBoy said:

    The way I did was a pain.  I put an S15 helical centre into my R32 housing using R34 4.11 crownwheel and pinion, S15 stub axles and S14 driveshafts.

     

    It doesn't have to be that hard.  The R33 diff will go straight into an R32, with some futzing with front bushes and changing the back cover back to R32.

    Cool so can keep setup except for diff, not familiar with futzing expression. Whats that?

    So use 33 diff and housing, but put the 32 back plate on.

     

     

    Questions about diffs

    in Drivetrain and transmission

    Posted

    19 minutes ago, GTSBoy said:

     

    4.3 is really short.  For a pissy little engine like an RB20 that's good.  For a bigger, torquier engine like an RB25, higher gears are better.  Hence going to the 4.11 that the R33/4s had.  There wasn't a readily available 3.9 gearset available when I was building my Frankendiff, so I just used the 4.11s.

    I'm sure the RB25 would pull 3.7s.  It's doing nearly 3000rpm on the highway in 5th, it could certainly use longer legs.

    Is it a pain to change to a 33/34 diff? Many things have to change?

    Questions about diffs

    in Drivetrain and transmission

    Posted

    26 minutes ago, Piggaz said:

    That really doesn't answer the question mate.

    You've obviously sat down and thought about the potential gains of a diff ratio change. What are you hoping to gain?

    For what's it's worth, put a RB25 NEO in it and enjoy life.

    I want to have everything to help me with my acceleration as much as possible, non engine parts.

     

    2 minutes ago, GTSBoy said:

     

    Well......what you learnt is not true.

    For drag racing, sure, go for a short diff ratio.  But turbos really like tall diff ratios so you can load the engine up in each gear and get a bigger run in each gear.

    My R32 had the obligatory 4.3 diff in it.  When I did the RB25 transplant I put a 4.11 into it, and if I could have found a good way to do a 3.9 I would have.  3.7 was an option but would perhaps be a bit too tall.

     

    And your diff oil does not need to be changed every year.  And you especially do not need to be putting LSD compatible oil in it (just in case you are) because your stock diff will be a viscous piece of poo and does not work like a normal LSD.

    Ok, little confused, you said what I learned was wrong, but you mentioned that 4.1 is what you had and you wanted to go 3.9.  Yes I understand that 3.9, etc is good.  I wasnt saying that the shorter gears are better. Just what I learned about 4.3 and 4.1.   

    So you didnt like your 4.3?   Would it be worth it to put in a 4.1?  My engine later I am looking at is going to be a 25 or 26.  Why couldnt you do a 3.9?

    Questions about diffs

    in Drivetrain and transmission

    Posted

    2 minutes ago, Piggaz said:

    That really doesn't answer the question mate.

    You've obviously sat down and thought about the potential gains of a diff ratio change. What are you hoping to gain?

    For what's it's worth, put a RB25 NEO in it and enjoy life.

    What I learned is that cars with a 4.3 or 4.1 diffs are good. I learned that sometimes non turbo cars have those diff ratios to help it along.

    I learned that 4.3 or 4.1 diffs are good to have in turbo cars.

     

    I wasnt sure what mine is.   I am putting a Nismo LSD in mine.   I know my car is over 25 years old and the diff is most likely not working  correctly so I will put in the Nismo.

    I change the diff oil once a year to help keep the diff working as well as it can.

    Questions about diffs

    in Drivetrain and transmission

    Posted

    2 hours ago, KiwiRS4T said:

    Have you got an R32 RB20DE? If so you will have a 4.1 diff already (4.111 non abs or 4.083 if you have abs.

    There is no such thing as a good ratio. There is only fit for purpose. What do you want to do that you can't already?

    No, just checking.   Learned that 4.3 is good followed by 4.1 and some people put 4.1 on their turbo cars.

    If the diff ratio I have is good already, than I want change.

     

     

    Rb26 and RB25 engines

    in Forced Induction Performance

    Posted

    Hello,

     

    The store where I saw a built rb26 and a rb25 still have the items I believe.  They knocked the prices down to 1400 dollars for the 26 and 500 dollars for the rb25.

     

    If I buy either one of these engines, what should I get down to them before trying to put it into my car, r32 gtst.   The store doesnt know if the engines work or not.

     

    They checked the crank and it turns fine I believe.

     

     

    HKS 2530 Found

    in Forced Induction Performance

    Posted · Edited by yoshiii335

    8 hours ago, discopotato03 said:

    If you really want a fresh HKS GT2530 make sure the compressor wheel isn't damaged and preferably the compressor housing too .

    If the one you're considering is for an RB20 or 25 it will have an integral wastegate T3 flanged turbine housing so it can make any GT28BB based turbo bolt to your factory exhaust manifold . Having said that there are limits to what sort of power you can get from even the best GT28xxR turbo particularly on an RB25DET .

    If you expect an easy 260+ RWKW on petrol you probably really need a GT30 based turbo in a Garrett . GT3076R or GTX3071R would get you there easily with the supporting mods . GT2530s and similar are better suited to mild 2L 4s .

     

    A . 

    Thanks for everyone's help.

    How does the GTX 3071R perform on a rb 20 and rb 25?

     

    I have found only alittle info about them for those engines.  

    Rb20 Det Discussions And Questions

    in Forced Induction Performance

    Posted

    Hello

    This thread is not about if I should change out the rb20. This thread is to dicuss the rb20 det and get peoples experiences with it.

    I have a rb20 det with rb25 turbo with a HKS aculator on it. My car has a turbo back full 3" exhaust plus sports cat, pod, small return flow fmic, Nismo GTR fuel pump, stock injectors and a Mines tune.

    Car drives cool. Positive turbo spool at 2000 rpm. Drives good off of boost and is cool. Going to add a boost controller to be able to control boost better and have it come on sooner.

    Its fun to drive. Don't know what its like to drive one over 300hp.

    Later going to get a rb25 or 26 but for now the 20 is good. Havent taken it to the track yet but will soon.

    What is everyones experinces with this engine and what do you like and not like about it?

    Sway Bar Upgrade Needed?

    in Suspension, braking and tyres

    Posted

    Yoshii, we can't tell you what sizes to get.

    The ARBs affect the balance of the car (under-over steer balance that is). How much you need at the front and rear depends on the inherent balance from your actual springs and dampers, coupled with your own preference. If oversteer frightens you then you would be well advised to keep the rear bar smaller than the front. But if perchance you have much stiffer front springs than your rear, then the same size ARBs at both ends might still be non-oversteery. Impossible to advise you precisely.

    I have 24mm adjustables at both ends. Front set to hard, rear set to soft. That's pretty stiff, although it is possible to go a fair bit stiffer. The front stiffness aids turn in response, but does reduce grip in the wet! The rear stiffness tends to make my car quite willing to get the tail out. This is with 5+kg springs at the front and 3ish kg at the rear, with SK modified Bilstein B6s.

    How are you getting such low spring rates? Most of the coilovers I find in Japan for the car has a minimal of 8 for the front and 6 for the rear.

    Getting Power To Ground Questions

    in Drivetrain and transmission

    Posted

    Don't install a 2 way, buy better tires

    Don't worry too much about bigger rims and buy better tires

    Don't lower the car more than a couple of inches... and buy better tires

    once you have better tires, put better coil overs in it.

    ....

    J.

    I understand buying better tires,

    but why no 2 way? Whats wrong with HKS? Not sure how much car is lowered. I haven't messed with the height, the car is still the way it was when I got it. Already had the HKS Hyper D's on them. Its lowered some but not too much. Came that way.

    I know about the big brand tires, Dunlop, Yokohama's, etc but I am in Japan and they charge a premium for the really really good tires from those companies.

    From my experience the Federal's are good. Any model tire that is good that you can suggest?

    Don't want to use semi slicks for everyday driving because its rainy season now and I don't want to wreck.

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