RB20DET vs SR20DET

[cameron]

Hi Guys,

I've seen a few thoughs been clashed around the forums about these 2 engines performance wise, making big horsepower, the disadvantages of these 2 & How these 2 comapre in standard tune.

Which engine do you prefer, and why?, Keeping in mind the SR20 has an alloy block.

Jun

[Angry]

this is going to be interesting .....

for high reving ..joy riding and thrashing .. Rb20 would be my preference

but for pulling power , punch and off boost driveability .. Sr20 does pretty good for a 4cyl job .

just my thoughts

Matt

[someonestolecc]

My flatmate has a rb20 r32 and I have a sr20 cefiro.

His car struggles to get up the hilly street we live on in 2nd whereas mine tears up it (both off boost).

I love the sound and urge of the rb20 as it gets revs but to me to get anything out of it you have to rev it, and so i find myself having to thrash it to do anything.

My sr20 is a pleasure to drive under 2000-3000rpm pre-boost and it drives like a bloody fast 2litre pre-boost so i prefer that.

[DHK]

my mate has a nicely worked sr20det.. (2002nv if u have seen it around sydney), driven both his car n my rb25det...

for some reason i prefer the rb range...

[BHDave]

I like rb20's, having had one for a couple of years. But the SR is a better base engine in my opinion.

It's lighter, it has more bottom end torque, it's smaller and after market goodies are cheap as. And they make the same power near enough so that seals it.

[cameron]

I like SR20's because they are very snappy & the pull hard & they are very quick for a 4cylinder, the only disadvantage is because its an alloy block they fa#king expensive to replace if you blow your motor up. Thats why most people put RB20's into their silvia because its cheaper and a good power gain because of power to weight factors.

Another disadvantage with the SR20 is because again its an alloy block it can't be used in certain 1/4 Drag Racing classes - Look at (mark ashford -spelling?) 200sx, he had to go FJ20 because the SR is alloy block and is not aloud to be used.

RB20's are good because of their nice smooth reving & the ability to sustain high rpm in standard form.

--Thats all for now keep the thoughts coming-- arguements aloud.

Jun

[cameron]

Also what engine would you prefer for motorsport's - Drag, Drift etc... & Why!

[doridori32]

I have owned both SR20 and RB20. I like RB20 for its hi reving capability. But then again it has no torque with the factory turbo. Whereas the SR20 has great torque. Is it the turbo doing all the work ? or does the sweet crap all torque get interupted because of the old crappy turbo on the RB 20?

[pnblight]

Interesting thread RB vs SR well you could almost call it Torque vs Revs as these motor configurations (bore and stoke) are designed for quiet different charactorists.

SR is a light ,compacked and great torque

RB has awesome bang for bucks and is a great base to big a 2.4lt off as gtr rods and crank are cheap and you then only have to buy tomei piston ,which no matter what engine you have if your look for performance a good set of piston is essential and i thing the torque of the combo would be awesome, i know you can stoke SR but i dont believe any where near the $$ of the RB.

both motors are top notch (long live the turbo nissans)

I myself am having play with the smaller almost forgotten bother CA18DET and have seen a s13 CA run 9sec in japan, so i think i should be able to extract some good ponys out of it ,i will post results when done. :wassup:

[GTR-Ben]

I will have to say SR20.

The S15 Blacktop SR20DET engine is amazing, the responce and torque delivery is a lot better than the RB20DET (but there is a very large age gap there, and huge price difference)

On Sunday I was talking to a driver of an S13 Circuit car. And he went on to tell me he thinks the SR20DET (his was a old redtop, he said very little internal mods) was better than any RB motor for lasting power for a circuit car..

He said he was making 700 crank HP and that to have a car with an RB setup like his car would never go as good.. but he said it was more the torque which he liked. I don't recall the figure.. but it was A LOT of torque for a 2L 4cyl..

His dad however told my friend that this car would only last 5 meets.. i think an RB26 making 700HP would last a hell of a lot longer..

He was from the deep south.. so probably a bit backwards

What are some of you circuit racers opinions?

[Maxx]

IMO the RB20 only do better than SR is smoother, the SR is a bit rough.

The RB sounds better too...

But other than the SR is better at every area.

lighter & shorter allow it to sit closer to the firewall for much better balance, handling and stopping.

it perform better both on/off boost, and late model SR also have VVT.

more torque is obviously the most important issue for shooting out the corner, i agree the RB might able to rev higher, but why need to rev the shxt out of it when u can get it in lower rev?

i am interest if someone can post up some dyno to see which engine has wider power band.

when someone say RB20 is cheaper to build, i am not really sure, since we are talking 6 piston, rod, injectors and SR is only 4.

previously own a R33 RB25 and the S15 SR20 is possiblily to compare with it.

[slow13dude]

Go the RB

Cheap as chips, you can blow 3 engines and still have money in the bank.

[TTT]

4G63

case closed.

there was a similar thread in here somewhere where SK and _OMG put in a great deal of info about the RB and SR.

both guys know a great deal about their chosen engines..

kinda turned to a sh*t fight but it was good while it lasted.

maybe search for that and have a read.

[Sydneykid]

IMO the RB20 only do better than SR is smoother, the SR is a bit rough.

The RB sounds better too...

But other than the SR is better at every area.

lighter & shorter allow it to sit closer to the firewall for much better balance, handling and stopping.

it perform better both on/off boost, and late model SR also have VVT.

more torque is obviously the most important issue for shooting out the corner, i agree the RB might able to rev higher, but why need to rev the shxt out of it when u can get it in lower rev?

i am interest if someone can post up some dyno to see which engine has wider power band.

when someone say RB20 is cheaper to build, i am not really sure, since we are talking 6 piston, rod, injectors and SR is only 4.

previously own a R33 RB25 and the S15 SR20 is possiblily to compare with it.

You are joking aren't you?

Horsepower = torque X rpm

So what if the SR has Xlbs more at 4,000 rpm, it's a dead duck at 7,500 rpm. The RB20 is going strong to 9,000 rpm. It's simple maths. There is no way an SR can produce 20% more torque than an RB, but the RB can rev 20% higher. So the RB will always have more horsepower as long as everything else is equal.

Let's get down to the block issue, is there anyone out there who really believes that a standard SR alloy block can handle more boost than an RB20 cast iron block? Like it or not, boost = torque. So the RB wins again, it can handle more boost therefore it CAN make more torque.

This "SR's make more torque at lower rpms than RB's" is crap, any extra torque that an SR has is purely due to the tuning. Take a look at the stated torque outputs of the various models of SR's. The amount varies by more than 15% and the rpm by more than 20%, but they are all SR's. The difference is in how they are tuned, not that the SR design is somehow inherently superior.

It's a self fulfilling prophecy. You can't rev SR 's higher, so you choose components (turbo size, cams, porting etc) and tuning that work within the rpm limits. Oh wow it makes more torque at 4,000 rpm. Dah, it has to, 'cause it won't rev. If I tuned an RB the same, it would make the same, But I don't have to, 'cause I CAN get the RB to rev withoit spending big bucks on the valve train.

I could also get into rod stroke ratios, main and big end bearing speed at rpm, valve area, inertia mass etc etc. The bottom line is, for the same capacity, more cylinders = more horsepower. That's why F1 engines are V10's, not V8, or V6's or I4's. And nothing "shoots out of a corner" like an F1 car.

That'll get the SR lovers all stirred up.............

[MerlinTheHapyPig]

lol, this isn't a mitsubishi forum... GTFOH

don't get me started on how good the '63 is.....

i'd go the RB, just coz it's cheap to replace, doesn't matter if u blow it up - a very good criteria if you're gonna drift it - sr20's aren't as bulletproof as an rb20 and also 2-3 times the cost

You can't really compare the rb20det with a late model SR because they stopped making the rb20's in 1993. If you want a fair comparison, compare a VVT SR20 with a RB25DET Neo - or compare a rb20 from an r32 and an sr20 from an s13.

[Sydneykid]

both guys know a great deal about their chosen engines..

Let's get a couple of things straight, #1 I have more SR's than RB's right now. #2 I have more Chevs than both added together and I have more Hondas engines than Chevs. So RB's can't be classified as my "chosen engine".

[geno8r]

That'll get the SR lovers all stirred up.............

lol Post it in a Silvia forum & im sure you'll raise hell... heheheh :flamed:

[TTT]

I didn't mean chosen engine as in you personally haveit..

I meant in terms of preference between the 2 and experience in the 2.

as I said, 4G63 is where it's at..

hahahaha

[Sydneykid]

as I said, 4G63 is where it's at..hahahaha

Oh no, not another one that is kidding.....

Only Mitsubishi could be stupid enough to have MIVEC technology and not use it on the 4G63. With a proper variable cam timing and lift top end, it might be a reasonable engine. It takes us aftermarket enthusiasts to do job properly and put 4G63 bottom ends under Cyborg cylinder heads. That's makes a silk purse out of a sows ear....

Yeh, I know, I should post it on the Mitsi forums for a stir.....

[CerealKiller]

The RB20 engine note sounds better than the SR20. Case closed.