blacktop sr20det vs. rb25det

[ArticDragon192]

I think this will be the year the ka24 will shine.

Amen to that. BTW, you want RB w/o throwing off your balance, go RB20.

[carofchoice]

sr's seams to be one of the biggest modded engines in japan and i really never seen or heard anyone laughing at them. i have also driven my friends r33 gts25t and i wasnt really impressed. i would spank him in no time with my lighly modded 180. not nocking the engines but i wouldnt say one is better than the other, it all depends on how you set it up. the one thing i liked better about the rb's is the sound, its totally different than anyother engine.

[lofapoo]

Where's the CA love?

[Gold Digger]

i understand what your all saying...this is my 1st 240sx that i've ever owned, but i've owned a few nissans in japan to inlcude a r32 gtr, r33 gts-t, and a y32 gloria that had the vg30det. i've driven several silvia's, never a 180sx though, with the sr20det, and i was never very impressed. i think everyone might already know this, but in japan they got a hp law, making it illegal to sell from the factory with over 280hp. the rb26dett had to be majorly de-tuned to get it down to 280 so it could be legally sold. the rb25det also had to be de-tuned to stay below the specs of the rb26dett. with simple mods (under $300), the rb25det goes back to producing its true power of 290+hp. on the other hand, the sr20det never produced enough power to worry about this law, so for the sr20, the hp that you see is what you get.

I have never heard of this being a "law", but more that of a "gentelmans agreement" for the higher end engine. Also, I have never heard of any engine being de-tuned to make it under the 280 law. If that were true, then the R34 GT-R would in theory be the exact same as an R32...and we all know better than that. If you look at the torque specs of the 32's-34's, each chassis model got more torque. Granted, the whole philosiphy is, torque gets you moving, and horseposer keeps you moving, but still the R34 definatley has more than 280ps.

Redtop - 205Blacktop S13 - 205Blacktop S14 - 220Blacktop S15 - 250

RB25DET (Series 1 - 2 ) - 250RB25DET (NEO) - 280

280ps in a NEO 6 RB25...wow...I'm not saying this is untrue, but I have never heard of this...I will have to swing by a Red Stage and see if I can get an old brochure on a 25GT-t Skyline. If that's the case, I know what engine will be going into my C33 in a few years.

And as far as the RBvsSR goes, think about this, the SR is perfect for the S cars, due to their lightweight chassis, and the RB for the R and C class cars are good for them. Also, keep this in mind. I know of several Skylines, Laurels and Cifero's that have had SR's swapped into them. The meathod behind this madness is that for top speed and drifting, having a four cyl makes the larger cars more stable due to the center of gravity being moved back. Top Secret had a Toyota Supra with a 3SGT-E crankin out somewhere near 800ps, and turned over 200mph...food for thought.

[naha_music]

i'm not hating on the sr20det at all....i want to thank everyone for their inputs...the reason for this thread...


Modified by naha_music at 10:57 PM 12/24/2004

[Nismo_Freak]

i understand what your all saying...this is my 1st 240sx that i've ever owned, but i've owned a few nissans in japan to inlcude a r32 gtr, r33 gts-t, and a y32 gloria that had the vg30det. i've driven several silvia's, never a 180sx though, with the sr20det, and i was never very impressed. i think everyone might already know this, but in japan they got a hp law, making it illegal to sell from the factory with over 280hp. the rb26dett had to be majorly de-tuned to get it down to 280 so it could be legally sold. the rb25det also had to be de-tuned to stay below the specs of the rb26dett. with simple mods (under $300), the rb25det goes back to producing its true power of 290+hp. on the other hand, the sr20det never produced enough power to worry about this law, so for the sr20, the hp that you see is what you get.

With a RB25DET 300whp can be had with full BPU mods on the stock turbo. Now this is a full 60whp more than your average SR20DET... so there is a point there. However, average out the difference in price between the two and you can easily afford to upgrade the SR to the same 300whp spec. The RB will get onto boost sooner, but will weeze out on the top end as most stock turbo engines do. The upgraded turbo on the SR will help to insure adequate flow to substantuate very little power drop (if any). The RB does have the stronger gearbox if you so choose to build some 5 million HP beheamoth, but to me personally anything above the 350whp mark in the S-chassis is just more power to kill tires with. There is a point to where the extra power is a hinderance to actual performance in my mind. I know I do not share the same ideals as everyone else but there are those among us that agree.

The fact remains that on an economical standpoint (in terms of swaps) the SR is very very hard to beat. Moreso with the CA's market's fall lately with losing two very big backers (Tomei and JUN).

Honestly there is very little reason to swap in an RB apart from you just wanting it. There is absolutely nothing wrong with that, but recognize that from a dynamic performance standpoint with the S-chassis car the 4-cyl. turbo engine is king. It was not built for a 6, but that doesn't mean it should stop you from putting one in the car if you so choose.

[Nismo_Freak]

If you look at the torque specs of the 32's-34's, each chassis model got more torque. Granted, the whole philosiphy is, torque gets you moving, and horseposer keeps you moving, but still the R34 definatley has more than 280ps.

Differences in turbochargers, and a number of other elements can attribute to the change in torque.

Torque and horsepower are the same... you can't have one without the other. True measured acceleration comes from HP... something that has more low end torque will also have more low end HP, that is why it accelerates at a faster rate. However, it is always best to make your torque at a higher RPM because there you will have a greater efficiency to produce work. Work is defined as torque / time which is essentially measured as HP. However this is for another thread, another day.

[Nismo_Freak]

i guess that both motors has its strength and weaknessess. it seems like it just comes down to personal preference. since the sr20det is more readily available here in the u.s. w/ tons of aftermarket parts, it makes it more perferable. like i said, i've been around nothing but rb's, so naturally that's my personal preference. i know that it has it's disadvantages in a s13, and lack of parts here in the u.s., but it's something about the looks of an rb implanted in the car and the sound of the exhaust.....gotta have it!

Modified by naha_music at 5:24 PM 12/24/2004

Sounds to me like you had your mind made up before this thread.

[madbouncy]

Work is defined as torque / time which is essentially measured as HP. However this is for another thread, another day.

*yes I am doing this for the sake of arguing, no I am not good at physics*Work = Force * DistancePower = Work / Time

Torque is a vector quantity so I don't think you can divide it by time and get anything usefull. Which is why it's moved over to horsepower, which is a scaler quantity and a lot easier to deal with. Plus, since you're car isn't a disc spinning, torque alone's not going to be that useful. Torque shares the same units as work, but it's not a force or an energy, it's its own thing. Now, grantued, I'm a completely retard and it's 3am, which by definition means, if I'm proven wrong I will resort to the greatest form of retalation known to man, c*** knocking.

Also, about that law about the 280ps, don't they get around that by just saying the car is only 280ps and actually having the car make more? Plus, I thought it was a tax thing, like if they went higher they'd have to pay a special tax because of it. But, like I said, I'm a retard.

[themadscientist]

If you GT-R or Supra actually makes 280hp something is wrong with it.

[Gold Digger]

If you GT-R or Supra actually makes 280hp something is wrong with it.

Differences in turbochargers, and a number of other elements can attribute to the change in torque.

Torque and horsepower are the same... you can't have one without the other. True measured acceleration comes from HP... something that has more low end torque will also have more low end HP, that is why it accelerates at a faster rate. However, it is always best to make your torque at a higher RPM because there you will have a greater efficiency to produce work. Work is defined as torque / time which is essentially measured as HP. However this is for another thread, another day.

Nismo_freak, I agree...the point i was trying to make was about the comment naha_music made about the 26 being majorly de-tuned to make 280ps. There is no way anyone can say that with his post, the R32 had the exact same rating as the R34 Vspec. I agree that most of the changes were with turbos and maybe a little in the cams, but not a lot. And when you increase torque you increase horsepower. So, the comment that it's illegal to sell a vehichle with over 280 is incorrect. That is just a stated figure for the Japanese auto companies. That is also why foreign car makers to Japan, can sell 300 horseposer Camaros, Trans Ams, and makes like BMW and Porche. Its a gentelmans agreement between the Japanese automakers.

Nismo_freak...I agree with what you said...naha_music sorry, I don't agree with what you said. And yes, the SR or CA or even an old school FJ is the perfect setup for the S chassis...and the KA-T sorry i left that one out.

[naha_music]

check out the r32 description on motorex. it says right there about the hp regulationhttp://www.skylinegtr.com/HISTORY.htmlheres another write up from skylines downunder about the power regulation.http://www.skylinesdownunder.c...7d6b5about the detuning, it was never officially announced, but how else can you explain such high power increases with simple mods? when i had my gtr, i had sold it before i could do anything to it so it was kepted stock. as for my gts-t, i did several small mods on that to include a blitz downpipe, apexi intake, full tanabe exhuast, and a boost controller, and several other insignificant things, which in total cost me alittle over $500. i had my car dynoed at super autobacs in which it was putting out 317hp. i've never heard of a sr20 that had a 67hp gain from the same mods. i'm trying to find the copy of the dyno sheet cuz i know most of you all probably don't believe it.

[Nismo_Freak]

but how else can you explain such high power increases with simple mods?

It's a twin turbocharged 2.6L engine that revs easily to 8200 rpm stock.

I'd say that explains it just nicely.

What Nissan did was make a high VE and gave it just a little bit of turbo flow. That makes for a smooth torque curve and shelled it under the 280ps mark. It's no wonder that adding a $7 fishtank valve from Petsmart makes the engine gain 80hp... that isn't rocket science. I wouldn't say the RB26 is choked down more than any other turbo engine Nissan has made... they all gain alot of power with simple mods.

[naha_music]

It's a twin turbocharged 2.6L engine that revs easily to 8200 rpm stock.

I'd say that explains it just nicely.

i was refering to my rb25det, not the rb26dett

i definately like the stats on the s15 sr20 though. i've looked around on several shops, seems impossible to find.

[Nismo_Freak]

*yes I am doing this for the sake of arguing, no I am not good at physics*Work = Force * DistancePower = Work / Time

Torque is a vector quantity so I don't think you can divide it by time and get anything usefull. Which is why it's moved over to horsepower, which is a scaler quantity and a lot easier to deal with. Plus, since you're car isn't a disc spinning, torque alone's not going to be that useful. Torque shares the same units as work, but it's not a force or an energy, it's its own thing. Now, grantued, I'm a completely retard and it's 3am, which by definition means, if I'm proven wrong I will resort to the greatest form of retalation known to man, c*** knocking

Note I said essentially... I didn't say it exactly is. My point was that the relation between HP and Work is essentially complimentery. HP is just work over time, does that not mean that HP is Work as expressed per unit time?

Torque is torque, but it has a direct relationship to force. Again you can't have one without the other... so it's lunacy to say torque can't be declared indirectly as a "force".

Or in other words, my reasoning for using those elements to was meerly to talk about force and movement without divulging into an 18 paragraph long explination of what they are, what they measure, etc.

[Nismo_Freak]

i was refering to the rb25det, not the rb26

It's a larger engine with a larger turbo utilizing similar restriction as the afformentioned SR20.

However you are extrapolating elements of your arguement that are swaying from the original topic of discussion.

[Nismo_Freak]

i was refering to my rb25det, not the rb26dett

i definately like the stats on the s15 sr20 though. i've looked around on several shops, seems impossible to find.

If you do an SR20 ... buy an S13 engine. Allow me to explain.

- S15 Engine Setup (~4000)- FMIC- Etc.

Make approx. 280 - 300whp.

- S13 Engine Setup (~2500)- New S15 Turbo (~750)- Nismo 740s (~500)- Z32 MAF (~100)- Enthalpy ECU (~500)- FMIC- Etc.

Make 300whp with a less restrictive system, with 740's (further upgrade), etc. etc.

You could substitute the S15 turbo for a GT2871R and push 350rwhp... albeit I wouldn't suggest that on stock headgasket or cams (for efficiency reasoning).

Basically your money goes farther.

[naha_music]

i was planning on going through http://www.jspecautosports.comfor my motor, does anyone know if they are reputable, or know if any other better places to get a motor?
Modified by naha_music at 11:34 AM 12/25/2004

[madbouncy]

Note I said essentially... I didn't say it exactly is. My point was that the relation between HP and Work is essentially complimentery. HP is just work over time, does that not mean that HP is Work as expressed per unit time?

Torque is torque, but it has a direct relationship to force. Again you can't have one without the other... so it's lunacy to say torque can't be declared indirectly as a "force".

Or in other words, my reasoning for using those elements to was meerly to talk about force and movement without divulging into an 18 paragraph long explination of what they are, what they measure, etc.

yeah I get what you mean, hp is derived from torque so it is stupid to see people talk about wanting more of one than the other. I was just saying that torque looked at as a force, doesn't raelly tell you much since it's going in a circle, which is why hp is around. Honestly, I was just hoping for an 18 paragraph explanation to give me something to read.

I agree completely with what you say about the rb though. That's more why I've always liked v6's, because they sit even further back than an inline 4, so it helps offset the added weight to me. Though, if it bothers people that much, you could probably fit an engine behind the drivers seats of an s13 hatch easily enough. Underground knows more about that than me though, since he actually has a hatch.

[Silvia007]

[QUOTE=naha_music]i guess that both motors has its strength and weaknessess. it seems like it just comes down to personal preference. since the sr20det is more readily available here in the u.s. w/ tons of aftermarket parts, it makes it more perferable. like i said, i've been around nothing but rb's, so naturally that's my personal preference. i know that it has it's disadvantages in a s13, and lack of parts here in the u.s., but it's something about the looks of an rb implanted in the car and the sound of the exhaust.....gotta have it![QUOTE]

Man, if I have the cash, I would of gone RB, regardless, the SR is a very potent 4 cylinder engine and I love it. The guys in japan say RB all the way and SR's are jokes but the USA sucks when it comes to imported cars. Look what we got... a KA24DE and in it's NA form, nothing to be impressed about so jumping to it's native engine, the SR20DET, that's a "HUGE" difference where as in Japan, the original engine is the SR20DET and it's totally unappreciated because you guys have RB's everwhere you look almost.

If you're leaning towards the RB and it fits your budget... do it, atleast I would, I just don't think there's a wrong answer when it comes to choosing engines.

[Gold Digger]

I have to disagree with what you are saying about the SR being unappreciated. I haven't seen to many S cars runnnig around with an RB. The SR can be a beast if you have deep pockets. Places like Yashio Factory specialize in the SR engine, they even have a stateside 240sx with an blacktop hittin around 350 at the wheels and they use if for drifting...but I guess the whole discussion on this topic would be, choose what ever you feel would be best for your situation.

[Gold Digger]

And, where are all you guys getting this information that Japanese people say the SR is a joke? I live over here and I have never heard that. The SR is a well respected 4cyl. The RB is a well respected 6cyl. I have never heard anything about the SR being a joke...in Japan

[Silvia007]

I have to disagree with what you are saying about the SR being unappreciated. I haven't seen to many S cars runnnig around with an RB. The SR can be a beast if you have deep pockets. Places like Yashio Factory specialize in the SR engine, they even have a stateside 240sx with an blacktop hittin around 350 at the wheels and they use if for drifting...but I guess the whole discussion on this topic would be, choose what ever you feel would be best for your situation.

The way that naha says it, it does seems the SR is unappreciated.

[naha_music]

And, where are all you guys getting this information that Japanese people say the SR is a joke? I live over here and I have never heard that. The SR is a well respected 4cyl. The RB is a well respected 6cyl. I have never heard anything about the SR being a joke...in Japan

i just moved back to the u.s. from the tokyo/yokohama area last year. i've lived in japan for 9 years. while over there,at least the area i was living in, the rb was in a completely different class than the sr. rb's main competiion was of course the supras, evo, rx-7's, etc...., while the silvia, 180sx was classified in a lower group along with such cars as civics. but i do understand i need to take in consideration other aspects when doing a swap besides power, such as weight, balance, etc. which i've learned that the sr20 definately has the rb beat when it comes to a s13.

[Gold Digger]

well, then my question is, if you spent 9 years over there and you know what the RB is capable of, then why are you asking an opinion on what swap to do. Apparently you have a baised towards the RB...which I am not saying is bad. And I live 30 minutes from Tokyo-to in Saitama-ken . I just hit the Shuto expressway, and go straight for the C1 and can be there in 20 minutes...and I still have yet to meet anyone who thinks the SR to be a joke. I have a few friends still on base in Yokosuka, and most of those guys that have Sil's or 180's say they would never swap an RB to an S chassis because the SR has great, not greater, HP potential.

And of course the RB is in a different class than the SR...the RB's are torque monstors that can hold an a**load of power...but the SR is just a high reving beast with a great setup. If you run a Silvia against JZA80, BNR34, FD3S, GDB, EVO, or even a JZX110, it's gonna get a schoolin...cause those motors in those cars were built to race outta the box. But, if you have the funds, you can make a nasty SR.

And another note, if you watch any of the autobacs D1 Grand Prix videos, the S15's and a select few S14's have just as much power as, say, an FD3S...it just depends on what you want to do.

I respect that you have good knowledge of what have backed your agrument on, and the fact that you have about 5 years more than I do over here...but just from what you know from your area, doesn't mean its country wide. So, maybe just be a lilttle more specific of region than saying the guys in Japan this, and that. That's all that really starts me up. Other than that, I think you know your s**t. Anywho, I think I have gone on long enough...lets just all hit a bong...er...i mean get along.

[naha_music]

thanks c33 for the post above, i'm not trying to heat anyone up with this and yes i may be alittle biased when it comes to the rb. i mentioned earlier that this is my first s13, so i'm still not fully knowledgable on the car. the things that were mentioned in this discussion helped clarify most of the misunderstandings i had on why people prefer the sr over the rb in a 240. i've never seen any silvia's or 180sx's in japan with an rb either, most of the cars i've seen with the swap were all the big body cars such as the glorias, cefiro's, etc. as for the people in japan not taking the sr seriously, that was just my thought, not the entire country of japan, i apoligize for that. when i see the silvia's i always see them racing with the s5 rx7's, hcr32 skylines, and civics. these are all cars that get's little respect by most people, so i naturally assumed that with the silvia's as well. thanks again for all the knowledge that you shared with me!

[Juujai]

naha you saying the sr20det youve driven stock or whatever slow is not wrong, i think it is horribly slow stock. i still feel its slow even if it gets a new turbo. but an sr with a flywheel, driveshaft feels so much differnt to me though. an SR isjust a basic motor when stock. its decent not too powerful not slow it atleast breaks the 200hp mark. when tuned though it feels good and pulls hard

[naha_music]

sorry for bringing back a dead topic, but i had another question to ask. i was convinced my most that the sr20det is the better swap, so thats whay i'm deciding to go with, but my next question is...

i'm gonna be making my purchase sometime this weekend for the sr20det and i want to get some opinions first. which model sr20det would be the better swap for the s13? the s13 red? s13 black? s14? advantages? disadvantages? please explain your answers, this would help alot. thanks.
Modified by naha_music at 9:34 AM 1/14/2005

[Juujai]

i read somewhere saying that different drivetrains produce different powers. like the advantages and disadvantages or rr, mr, fr, 4wd, all wheel drive, ff or whatever. and it said that if the 34gtr becomes a rwd it will still have the same hp number but when it comes to the wheels its a lot weaker. it said 240s with rb26detts/rb25det ttranny is basically crap because it has to do with the drivetrain/weight whatever. it had this formula you could do to see what type of power youa ctually get from a handicapped body. im not too sure but someone explain to me why 300hp low turbo lag sr20s still suck in the 1/4 mile when the car is pretty light. about what 2500lbs with basic stripping =). tell me why a civic hatchbacks with ~200-220hp spank the crap outta us? they arent that much lighter but i got a feeling its the drivetrain.

that goes for the supra too 1000hp vs 650-700hp supras 1/4 mile times dont seem too much off with nice tuned aerodynamic bodies. i bet if the 2jz had a all wheel drive transmission it'll be different