please advise me on how to modifi my rb25det. i really want to go on with bigger turbo. what should i do? i already install bigger intercooler, can i go with bigger turbo without forging my piston? advise please. i want a stable engine 
i need advise from pro
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ask on club240, i bet 5 min later a shit load of ppl will let u know
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i work at a shop in atlanta that can help you...feel free to visit our website at speedforsale.com if you speak to someone tell them David Dysinger sent you. i am about to start my major mods on my 95 R33 as well
-dave
-dave
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Larger turbo means, you need more fuel and you need to tune it. You also have to make sure you upgrade your clutch that will take your new torque figures.
Now, what is your HORSEPOWER goal? What are you going to use your car for drag strip, autocross, street or little bit of everything?
Tuning is KEY, you can make a lot of power without melting your pistons, however, you can even melt pistons at 300 HP if you don't tune your car properly.
Larger turbo = Larger fuel injectors + highflowing fuel pump + Adjustable fuel pressure regulator + tuning device + dyno tuning = Good running reliable car.
I would recommend upgrading your brakes and suspension if you didn't do that already.
Now, what is your HORSEPOWER goal? What are you going to use your car for drag strip, autocross, street or little bit of everything?
Tuning is KEY, you can make a lot of power without melting your pistons, however, you can even melt pistons at 300 HP if you don't tune your car properly.
Larger turbo = Larger fuel injectors + highflowing fuel pump + Adjustable fuel pressure regulator + tuning device + dyno tuning = Good running reliable car.
I would recommend upgrading your brakes and suspension if you didn't do that already.
Ok, I will assume you mean 400hp at the engine not the wheels. So I reckon around 250-260 rwkw is what your after.
If your car is stock these are the things you will need to do to get where you want to be... well what I would do at least (in order):
- Full 3.5 inch exhaust (not just cat back). If you can afford it get a split dump pipe otherwise a one piece dump/front pipe will be ok.
- Replace the lunch box sized I/C with a aftermarket front mount install with a decent core size. Find one that flows well and doesn't drop much pressure of the core (no more than 2 psi). Most of the Japanese kits for the 33's are fine and really easy to install yourself.
At this point you can buy a boost controller put the boost to 10-12 psi. Keep in mind a few things at this point. The first is that I wouldn't recommend running much over 12 psi on the standard ceramic turbo. Secondly the amount of boost you can run without some sort of fuel management system will be restricted on how much the standard ECU will let you. As you increase the boost (especially if it's too high) the standard ECU will try to richen the air/fuel ratios and can make your car misfire at higher revs.
- Next I would look for some sort of aftermarket ECU. I would suggest a Power FC as it makes for an easy install (true plug and play - even has base maps for you to drive it down to where you can get it tuned) but there are heaps of others around. I would probably avoid a quick fix like a SAFC or other fuel interceptors/piggy backs as for the power your after full engine is probably your best bet. I assume your choice of ECU may be largerly restricted to who around where you live can actually tune the thing. You really don't want someone without any experience "having a go" and tuning your car with a new Power FC... Find someone who you can trust or has a good name behind them.
So pretty much at this point your car will be making somewhere around the 200-210rwkw mark at 12psi). Your fuel pump and injectors will reach their limit if you go much higher on the standard fuel line pressure. Some say the air flow meter is almost reaching the limits of its resolution but I have seen R33 GTS-t reach 260rwkw still with standard AFM's. If it does become an issue you can always find a second hand Z32 AFM (not always cheap though). From memory it's a direct plug in.
If your wishing to continue and make more power from here it's time to upgrade the fuel system and turbo. So a rising rate reg and a new fuel pump are in order. You can use something like a Bosch 040 or 044 (the bigger one of the two, I can't remember which one or a nismo item). The nismo item is nice because it is a simple in tank install and sits where the stock item did in the cradle. The Bosch items require a bit more work and can be noisier.
I would suggest something like a HKS 2535 as it is a perfect match up for the RB25 with minimal lag for street use. But as you probably already know there are many many types to choose from.
Anyways, I hope that helps a little. Sorry if it doesn't make much sense but it's late and im very tired. Feel free to ask any questions you have.
So I reckon around 250-260 rwkw is what your after.If your car is stock these are the things you will need to do to get where you want to be... well what I would do at least (in order):
- Full 3.5 inch exhaust (not just cat back). If you can afford it get a split dump pipe otherwise a one piece dump/front pipe will be ok.
- Replace the lunch box sized I/C with a aftermarket front mount install with a decent core size. Find one that flows well and doesn't drop much pressure of the core (no more than 2 psi). Most of the Japanese kits for the 33's are fine and really easy to install yourself.
At this point you can buy a boost controller put the boost to 10-12 psi. Keep in mind a few things at this point. The first is that I wouldn't recommend running much over 12 psi on the standard ceramic turbo. Secondly the amount of boost you can run without some sort of fuel management system will be restricted on how much the standard ECU will let you. As you increase the boost (especially if it's too high) the standard ECU will try to richen the air/fuel ratios and can make your car misfire at higher revs.
- Next I would look for some sort of aftermarket ECU. I would suggest a Power FC as it makes for an easy install (true plug and play - even has base maps for you to drive it down to where you can get it tuned) but there are heaps of others around. I would probably avoid a quick fix like a SAFC or other fuel interceptors/piggy backs as for the power your after full engine is probably your best bet. I assume your choice of ECU may be largerly restricted to who around where you live can actually tune the thing. You really don't want someone without any experience "having a go" and tuning your car with a new Power FC... Find someone who you can trust or has a good name behind them.
So pretty much at this point your car will be making somewhere around the 200-210rwkw mark at 12psi). Your fuel pump and injectors will reach their limit if you go much higher on the standard fuel line pressure. Some say the air flow meter is almost reaching the limits of its resolution but I have seen R33 GTS-t reach 260rwkw still with standard AFM's. If it does become an issue you can always find a second hand Z32 AFM (not always cheap though). From memory it's a direct plug in.
If your wishing to continue and make more power from here it's time to upgrade the fuel system and turbo. So a rising rate reg and a new fuel pump are in order. You can use something like a Bosch 040 or 044 (the bigger one of the two, I can't remember which one or a nismo item). The nismo item is nice because it is a simple in tank install and sits where the stock item did in the cradle. The Bosch items require a bit more work and can be noisier.
I would suggest something like a HKS 2535 as it is a perfect match up for the RB25 with minimal lag for street use. But as you probably already know there are many many types to choose from.
Anyways, I hope that helps a little. Sorry if it doesn't make much sense but it's late and im very tired.
Feel free to ask any questions you have.1 - 7 of 7 Posts
