How can a F22c make same power a Rb25det does..?

[Drift-wood]

I have been researching deeply into the type of engine I want to put into my s14. So I have been reading everything about all engines that have been put into a S14 chassis.

Well I was reading that the RB25DET reaches around 400 WHP when you start having to replace internals to make it reliable and hold the power.
Now this leads to my question, how does S2000 F22C make 350-400 whp on a stock block with a turbo and a 2.5 L Inline six can only reach 400 whp with stock internals?

I'm just curious the displacement is only 300cc difference so it can't all be in that.
I work with a guy that has a s2k running 375whp+ for over 2 years on a stock bottom end so I know it isn't just smoke and mirrors.

I just want to know what limits the RB25det in stock form that keeps it from going over 400whp reliably?

[Gabes13]

It's all about structural design, not number of cylinders. Tuning plays big role in longevity and output. And I'm sure you can push more than 400 on a stock bottom 25 without much fear.

[Joe]

2.2 vs 2.5 isnt that big of a difference.

they both use s*** internals not designed for high power (as do nearly all manufacturer stock engines) so this isnt anything out of the ordinary.

[AZhitman]

"Reliable" is relative.

If tuning is perfect, 400hp is an imaginary limit... Magazine tuning isn't real-world results.

I've seen Honda engines s*** the bed on 5psi, and I've seen KA's make silly power on stock guts. It's all subjective.

It's really not that cut and dried.

Oh, and BTW - For the money you'll spend on EITHER of those, you'll have a lot less drama and a lot more fun with an LS.

[Joe]

glad youve finally seen the light greg.

[Drift-wood]

I was going from what I had read on other peoples experience. I do agree it is all realtive one engine can be a wonder while a exact same motor can blow with the same tune and every thing. From what I have learned a 6cyc would have less load per cyilinder than a 4cyc so it should obtain the same power with lower tempeture and stress.

Lol my main choices are rb25det neo or a vh41de...
Just can't make up my mind. I want to obtain 350+ who while having a high revving motor.

[Bluefire]

And if you only knew how much money it takes to properly turbo an f20/f22, you'd see that an Rb25 will make over 400 reliably and a lot easier than an f20 or f22

[Drift-wood]

I agree bluefire I think I realize the difference. Though I should have thought about it before I posted. The rb25 will reach and sustain 400+who and relibily stay there while the f22c may reach that number but will be seeing alot more stress.

[AZhitman]

VH41DE won't get you anywhere near 350hp w/o boost. GL with engine management, and finding parts. Not a common engine, considering it was only used for 5 years.

Our RB is sitting around 260 with simple bolt-ons.

350whp in a S-chassis is a lot more than most people think, and few driver can make good use of that kind of power. Sounds good in a magazine, and bragging to buddies, but you'll spend more putting it to the ground than you ever did on the swap. Even sketchier with boost.

LS will do 350whp with headers and a cam. High-revving becomes irrelevant.

[julio]

I agree bluefire I think I realize the difference. Though I should have thought about it before I posted. The rb25 will reach and sustain 400+who and relibily stay there while the f22c may reach that number but will be seeing alot more stress.

More stress is definitely true since the centrifugal/centripedal forces acting on the rotating assembly is far greater than the power output around 10k rpms.

[ST240]

VH41DE won't get you anywhere near 350hp w/o boost. GL with engine management, and finding parts. Not a common engine, considering it was only used for 5 years.

Our RB is sitting around 260 with simple bolt-ons.

350whp in a S-chassis is a lot more than most people think, and few driver can make good use of that kind of power. Sounds good in a magazine, and bragging to buddies, but you'll spend more putting it to the ground than you ever did on the swap. Even sketchier with boost.

LS will do 350whp with headers and a cam. High-revving becomes irrelevant.

Almost... ALMOST wishing I went LS instead of RB30. But the LS hype driving used engines up is so out of control its not even funny.

[Drift-wood]

Sorry stupid iPhone lag double post.

[Drift-wood]

Hmm this whole discussion is making lean more to the rb25det neo than the other options I have been looking at. I do appreciate all the input from everyone. My s14 is my baby and I'm wanting to build a very rounded car in the style that I like. That's why the wide power band with high Rpms is important to me I love the sound of a screaming inline six sound.

[Krazykouki]

I just turned the boost up on my RB25 to 13 psi. I have 275's in the rear on my car and have traction problems even in 3rd. All I did was put in a Walbro, Z32 MAF, FMIC, and tuned it with an SAFC 2.

I love it now. I've ridden in and driven boosted S2k's and I like them but I like the RB better.

[Yellow4g63]

I never thought the RB25 would have a problem with 400hp if it's tuned right? News to me.

[Drift-wood]

I do have another questionfor you guys with rb25/26
Did it make any noticeable difference In the cars handling? Did you get it in and then drive it and could tell night and day difference or was it just a little different?

[Joe]

Almost... ALMOST wishing I went LS instead of RB30. But the LS hype driving used engines up is so out of control its not even funny.

wtf are you talking about

these things have been in high a** demand since they came out in 98. only recently did the import community pull its head out of its a** and realize how awesome these engines are. hod rodders and other sane people have been doing this swap and keeping the price high for years

also, once you realize that its a FAMILY of engines, not just ls1, ls2, ls3, ls6, ls7, lsa, you realize there are literally millions of LS based engines out there

ALL of the truck and SUV's that have v8's got a variant of the LS engines that are far cheaper and make the same power or have the exact same potential.

[AZhitman]

If you can get an RB for less than an LS, you bought a turd RB.

I'd swap my RB for another LS in a heartbeat.

I'd swap my 400-hp KA-T for an LS in a heartbeat.

I'd swap my wife's VQ40 for an LS... wait.... hmmmm....

[Carl H]

IMHO dont bother with the r33 rb25, spring for the r34's neo if you're gonna swap in an rb25...best of the lot and much more power out of the box.

ls engines are phenomenal engines for sure, but at an average swap cost of ~7k for an ls swap it is almost cost prohibitive...a nice rounded rb based swap can be had for that or less (if you manage your money).

[flatrate]

people have made 700whp on stock F20/22c's there badass engines, the heads flow better than anything nissan puts out and they do have better internals than an Rb25.. RB's really arent that great unless the heads are ported and there built to all hell... my h22a honda makes much better power than my RB does

[5upa_mari0]

Check out s2ki.com they have many stock motor S2000's making well over 400whp and change the headgasket to a thicker one and you can make up to even over 700whp on stock internals. The internals on that motor are forged and the head flows amazing. Check it out

[s14_sport]

my h22a honda makes much better power than my RB does

Thats great...but, where's the torque?

[themadscientist]

I never met an H22 that could best my RB20, a 25 would do even better. Ultimately, in the most general of terms, an engine is an engine. Honda can build an engine, Nissan can too, Toyota arguably better, etc. A solid engine set up properly will make power and last.

Most of these RBs you see are junkyard-sourced with unknown maintenance histories where the Fs are often first or second owner cars and Honda owners are seriously anal about their maintenance. By the third owner you start to get to the people that beat them like the Japanese owners of the RBs.

I've made respectable power out of seemingly simple engines that I set just right and took care of and pissed off some people that on paper should have mopped the road with me, but their setup was all screwed up.

Either motor is a great starting point and done right can be powerful and reliable. Done wrong and either will puke up their guts like a sea cucumber. Don't get caught up in the magazine/forum fanboi hype. Whichever one does it for you, go for it.

[Darius]

400hp is no sweat for a stock bottom RB25 with a marginal tune. 500hp is no sweat for a stock bottom RB25 as long as it is tuned properly for the fuel being run through it.

You're not comparing apples to apples when comparing an F2xC to an RB25 because the RB2x motors went into production about 20 years prior to the F-motors found in the S2000. And you're really only comparing peak hp numbers. An RB25 has 25% more displacement, which translates into being a torque monster compared to the F2xC engines. With that said, a 400 hp RB25 would walk a 400hp F20C or F22C (assuming the same vehicle, of course).

Really what it boils down to is 20 years in head development, computer aided flow modeling to improve overall efficiency, and tighter production tolerances found in the F2xC that make it such a great engine.

[flatrate]

my h22a honda makes much better power than my RB does

Thats great...but, where's the torque?

My h22a made 440wtq and 610whp on 28psi... with a 6265 precision with pump and meth

Rb's are in the general area of this... they are by no means torque monsters... if you think that your a tard...

With a 30r my RB made 412whp and 330wtq on 20psi 92 pump

With a 30R on my h22a (same exact turbo used) i made 480whp and 376wtq on 17psi 92 pump

both have built engines... both using bone stock cylinders heads... (no cams porting valvetrain etc)

Im not trying to put down the RB motors... i love my RB and the music it makes...

RB's can make insane power, but it takes more work in cylinder head modifications etc which most poeple dont do ( i didnt) to make power with them

The last H22 motor i built for a friend put down 750whp and 570wtq on C16 TO4Z turbo ( BB 67mm) on 35psi... thats pretty nasty... show me an RB20 or 25 thats doing that...

again before people switch gears and call me names for going to bat for a honda... im just being realistic ive built and messed with both and so far my H has taken the cake


Also, what Lip is that on your kouki?

[Yellow4g63]

My h22a made 440wtq and 610whp on 28psi... with a 6265 precision with pump and meth

Rb's are in the general area of this... they are by no means torque monsters... if you think that your a tard...

With a 30r my RB made 412whp and 330wtq on 20psi 92 pump

With a 30R on my h22a (same exact turbo used) i made 480whp and 376wtq on 17psi 92 pump

both have built engines... both using bone stock cylinders heads... (no cams porting valvetrain etc)

Im not trying to put down the RB motors... i love my RB and the music it makes...

RB's can make insane power, but it takes more work in cylinder head modifications etc which most poeple dont do ( i didnt) to make power with them

The last H22 motor i built for a friend put down 750whp and 570wtq on C16 TO4Z turbo ( BB 67mm) on 35psi... thats pretty nasty... show me an RB20 or 25 thats doing that...

again before people switch gears and call me names for going to bat for a honda... im just being realistic ive built and messed with both and so far my H has taken the cake


Also, what Lip is that on your kouki?

All kidding aside VTEC heads flow really good. Why don't you buld a SR20VET or SR22VET or SR24VET you should get the same power since it's a VVL head.

[Sil240]

IMO the RB25 will be cheaper and make more USABLE power.
Power and torque under the curve.

Yeah your H22 head flows better than an RB20 & it makes more power but unless these are drag cars it doesn't really matter.
Since your H22 is FWD, getting that power to the ground is going to be fun.

[flatrate]

IMO the RB25 will be cheaper and make more USABLE power.
Power and torque under the curve.

Yeah your H22 head flows better than an RB20 & it makes more power but unless these are drag cars it doesn't really matter.
Since your H22 is FWD, getting that power to the ground is going to be fun.

were talking less than a half a liter of a displacement advantage... more power under the curve is very minimal here... if your going for 600+whp on either engine "power under the curve" will suffer..

CHEAPER are you serious? just to get a running RB in a 240 or whatever platform your going with will cost well over 3k and now you have a stock freshend up RB... managment injectors turbo etc etc

Hondas are cheap motors fit into ANYTHING sleeved block pistons and rods and you have something that can make 600whp all day being they were made in the US its not hard to find them ready to go... cheaper MUCH cheaper

My h22a head stock flows much better than most modified RB20/25/26 heads... they flow about 275cfm stock

I get the power down ALOT better than you would ever think actually.... due to boost by gear and bias ply DOT tires.. to put this in perspective... in 2nd gear on 17psi ( almost 500whp) i dont spin on a warm tire

Here is a video of the car racing a turbocharged mustang with a 70mm turbo from about a 30 roll.. ( i wanted a dig race but he didnt)

http://www.youtube.com/watch?v=CYoedhgmw10

[Yellow4g63]

Dang the VE head flows around the same as that H22 head. Well I think everyone should know if it starts with RB it = $$$$$ lol.

[Sil240]

I quickly looked up swap prices.

F20 _ $4400
RB25 _ $1700
$2700 difference

Then f20 Turbo kit
Then RB Turbo upgrade plus other supporting mods

Standalone ecu or hondata - Justine vg ecu

Of course you'll need custom mounts and plumbing for both.


I don't know the prices but you do the Math.

I still believe you will have more power under the curve with a. 5 liter difference and 2 more cylinders. Someone find some similar dynos, you should be able to see. Even though everything comes down to the tune a difference should be visible.