Jump to content
SAU Community

Forged Rb20


Recommended Posts

but i'll still put a set of forged rod's and pistons for that added piece of mind and go from there...

Forged rods are a waste of money. Its rare for 2lts to throw rods or even pistons. A good tune is better than spending money on "piece of mind" bits and pieces. Listen to the advice people are offering.

Link to comment
Share on other sites

  • Replies 209
  • Created
  • Last Reply

Top Posters In This Topic

ok so it may of looked like you guys have convinced me i might not go forged internals after all and save the doe for rx-7 instead i'll just run new sump, oil pump, cams, and nice turbo and tune and look more for around 260-270rwkw cheers for all the advice plus i've got a supercharged stato that's in need of some work to be done as well :thumbsup:

hey anyone know what those GTX3071 are like on a 20? heard they should be decent

Link to comment
Share on other sites

I lol every time I read someone say "I want to do something different"

If thats the case, then take up gardening, or painting maybe?

Go to a track with a forged RB20, and no one will say "oh wow, thats different", they'll say "why the f**k did he waste $10k on a RB20, when my stock RB25 can make the same amount of power, earlier, and with more torque" lol

Edited by The Mafia
Link to comment
Share on other sites

Because the RB20 needs all the response it can get, you'll lose that with larger cams.

Also porting is a waste of money on a 20 head. They flow around 30% less than a RB25 head anyway.

Please read the 260rwkw RB20 thread (linked via the FI Guide). You'll see people have tried various setups and the setup that is the best for 260rwkw overall?

TD06 Greddy KIT, stock RB20, decent tune

People dont bust their 20 gearboxes, they don't destroy motors either :)

People tried cams, plenums, different manifolds, cam gear settings etc.

Overall these items - some of them big $$$ items – made no difference and in some cases the setup actually LOST power and/or response.

Being a pioneer is all well and good, but if you are on a budget, why bother? People post up all this information to help everyone else for free, I say use it :)

Link to comment
Share on other sites

Why does everyone say "keep standard cams"? I mean I know that the head on the rb20s suck, but if ported the aftermarket cams will make more power then standard ones. What gives?

They come out of the factory with big cams for their capasity. RB25's run the same spec cams and they are 25% bigger, and there is a different circuit car down here running a RB25 with stock cams, and it makes 450rwkw.

Link to comment
Share on other sites

Why does everyone say "keep standard cams"? I mean I know that the head on the rb20s suck, but if ported the aftermarket cams will make more power then standard ones. What gives?

Putting in bigger cams doesnt automatically make the engine have more power, the motor will end up been over camed and if anything might make less power, I have never really heard of anyone making decent gains on a 20 with cams, even the crappy pon cams, most people who have tried end up going back to standard ones as they are heaps better.

Cam gears yes thats a cheap mod that will give you some decent gains/response, highly recommened that on a 20.

If you read the thread nismoid mentioned all info is in there.

Link to comment
Share on other sites

drop a stock 25 in there with mods... tuned correctly it will return years of service at 280 rwkw with no problems PROVIDED your bolt ons are up to the task

Just do this.

You drive a skyline, nothing you do will be different.

Also rb20 sucks ass compared to rb25, no VCT, lower compression and yeah, just bin it and get a 25. The difference is night and day. Don't bother rebuilding for under 300kw.

I lol every time I read someone say "I want to do something different"

If thats the case, then take up gardening, or painting maybe?

Go to a track with a forged RB20, and no one will say "oh wow, thats different", they'll say "why the f**k did he waste $10k on a RB20, when my stock RB25 can make the same amount of power, earlier, and with more torque" lol

This. Save your money.

Edited by Rolls
Link to comment
Share on other sites

I kinda get what your saying, but I just cant see how the head cant be made better with a little work. The head is what makes the power, it really doesnt make sense. Stock rb20s have 240 dur cams, thats not that big of a cam for a 2.0. I know you guys are going to say, its been done before. I just cant see how a nice head job ( not a lot is needed sometimes), cam gears, and some 264 dur cams are worse then stock. Even honda vtec motors gain power from head work and cams, and they have some of the best flowing heads from the factory end of story.

There is a guy that was making 398whp stock motor with a tune, injectors, turbo, and cams. I just cant see how he would be at that same power or less with a nicly worked head. Keep in mind that the better the head flows the faster boost comes on too. I see he says he makes full boost (16psi) at 5200ish, I would think that would be closer to 4700(ish) with better flow.

Please correct me if I am wrong, but this is the way I have learned it from my v8 building buddies.

I will have to look at the thread that you guys speak of.

Edited by Driftnuttz
Link to comment
Share on other sites

i agree with driftnuttz, i was reading that 260kw thread and i was reading even though it's years ago that most of you guys were making peak power between 5-6000rpm now wouldn't some cams help increase the top end and if you can get the head to flow wouldn't you be able to keep similar response just with more top end?

Link to comment
Share on other sites

I kinda get what your saying, but I just cant see how the head cant be made better with a little work. The head is what makes the power, it really doesnt make sense. Stock rb20s have 240 dur cams, thats not that big of a cam for a 2.0. I know you guys are going to say, its been done before. I just cant see how a nice head job ( not a lot is needed sometimes), cam gears, and some 264 dur cams are worse then stock. Even honda vtec motors gain power from head work and cams, and they have some of the best flowing heads from the factory end of story.

There is a guy that was making 398whp stock motor with a tune, injectors, turbo, and cams. I just cant see how he would be at that same power or less with a nicly worked head. Keep in mind that the better the head flows the faster boost comes on too. I see he says he makes full boost (16psi) at 5200ish, I would think that would be closer to 4700(ish) with better flow.

Please correct me if I am wrong, but this is the way I have learned it from my v8 building buddies.

I will have to look at the thread that you guys speak of.

By all means give the head work and cams a go, will be interesting to see if you and your tuner come up with a combination that works. Some get a setup that works and people swear by, others enjoy less sucess.

Dont confuse 4 cylinders and 6 cylinders either, SR20s do seem to like cams well before RB20s

http://www.skylinesaustralia.com/forums/topic/58229-top-rb20-club-do-you-have-over-260rwkw/page__st__1740__p__5804707__hl__rb20+260__fromsearch__1#entry5804707

Link to comment
Share on other sites

Go to a track with a forged RB20, and no one will say "oh wow, thats different", they'll say "why the f**k did he waste $10k on a RB20, when my stock RB25 can make the same amount of power, earlier, and with more torque" lol

hahahahaha so true!!!

Link to comment
Share on other sites

By all means give the head work and cams a go, will be interesting to see if you and your tuner come up with a combination that works. Some get a setup that works and people swear by, others enjoy less sucess.

Dont confuse 4 cylinders and 6 cylinders either, SR20s do seem to like cams well before RB20s

http://www.skylinesaustralia.com/forums/topic/58229-top-rb20-club-do-you-have-over-260rwkw/page__st__1740__p__5804707__hl__rb20+260__fromsearch__1#entry5804707

this is true... SR's struggle to make over 230 rwkw with stock cams. drop some cams in and its a whole different ball game.

Link to comment
Share on other sites

The head is flowed to suit the stock engine. Spending money on it to return minimal gains is the same as spending money on forged parts.

The std cams are also the ones -again see the thread where others have spent money and have PROVEN results- that suit the best. You want to take a 2lt motor that hasnt got the most usable power down low, and shift the power up even more? Making it worse to drive off the lights to see a better curve on the dyno once you hit 100km/h doesnt make much sense.

Link to comment
Share on other sites

Please correct me if I am wrong, but this is the way I have learned it from my v8 building buddies.

I will have to look at the thread that you guys speak of.

The point is for bugger all money you can drop a stock rb25 in which will do what you want for ~$1500. What you want to do will cost shitloads, and if you were to spend that same shitloads on an rb25 or rb30det then it would be magnitudes better again!

Don't waste your time or money on the rb20, even with all the headwork in the world it is still only 2L and short stroke, it will always suck down low, head work and cams will make it worse!

a stock rb25det with VCT and stock cams compared to an rb20 with headwork and cams that makes the same power will have almost double the torque at 2-3krpm it will also have cost less than half the price.

it is a no brainer!

Edited by Rolls
Link to comment
Share on other sites

I kinda get what your saying, but I just cant see how the head cant be made better with a little work. The head is what makes the power, it really doesnt make sense. Stock rb20s have 240 dur cams, thats not that big of a cam for a 2.0. I know you guys are going to say, its been done before. I just cant see how a nice head job ( not a lot is needed sometimes), cam gears, and some 264 dur cams are worse then stock. Even honda vtec motors gain power from head work and cams, and they have some of the best flowing heads from the factory end of story.

There is a guy that was making 398whp stock motor with a tune, injectors, turbo, and cams. I just cant see how he would be at that same power or less with a nicly worked head. Keep in mind that the better the head flows the faster boost comes on too. I see he says he makes full boost (16psi) at 5200ish, I would think that would be closer to 4700(ish) with better flow.

Please correct me if I am wrong, but this is the way I have learned it from my v8 building buddies.

I will have to look at the thread that you guys speak of.

That is my car in the vid. On low boost 15psi my peak power checks in @ 7600-7800 then starts to fall off slowly to 8k. I haven't had a chance to see where the peak is at higher boost because of the maf issue. 25psi on that turbo would mean bigger numbers but I don't really need it, I under estimated this turbo when I picked it lol.

Link to comment
Share on other sites

Ok guys think about what everyone is saying. i know that the rb25/26/30 is better, but here in the states its a $2500 swap.

I was reading a few threads on here last night and saw roy himself say that he thinks the turbo he was using was holding him back not the cams or head.....

A better flowing head will increase both bottom end and high end(granted more highend then lowend). Now because your moving more air in and out you get a faster spool and there is more midrange. Then you ad cams because once the head flows a bit better the cams will start to show gains. Yes cams are known for moving the powerband higher, but that is what cam gears are made for. Cam gears arent made to make more power, they are made to adjust the LSA (lobe seperation angle). When you adjust the lsa it moves the powerband around. Thats why when you buy a cam for older v8s they ask what lsa you want.

http://www.team-integra.net/forum/14-performance/15390-cam-gear-tuning-basics.html

^ that is an Integra site, but its the same with every engine as alll engines make power the same way.

If this sounds like I am just arguing with everyone, I am sorry. I just come from a world where in order to make power you work with the head cause thats where all the work is done and the bottom end just needs to be able to hold the power.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share




×
×
  • Create New...