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Flux Capacitor is the key
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Discussion Starter · #1 ·
Ok...I've searched this thread enough already. Supposedly people are saying that you have to get a whole new tranny, and new axle if you want to get an SR20DE engine. Just for a 140 hp? Is this true or what people?
Second off..
Shouldn't a 50 shot of NOS bring the hp to about 160hp? Do you have to get a new tranny or a new axle for that?

If your answer is yes...then nevermind it.
If your answer is no...then what the hell. Why do you have to change the tranny and axle for the engine swap and not a nitrous injection?

I'll search for the thread that says this...
 

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you need a new tranny and axles because theyre completely different engines. just because they fit in the same car, doesnt mean theyre related in anyway, maybe just the size. almost all 90s hondas are powered by "b-series" motors. (b16, b18, b20, etc.) many parts are interchangeable between those motors, because they are in the same family. maybe if you wanted to swap in a ga15 from japan, you could use your axles and tranny, considering you have a ga16-powered car. thats why most people recommend starting w/ an se-r and swapping to a sr20det or something like that. and yeah, there is a thread on here where a guy put a zex 50 shot in there w/ no mods. said it worked great. so go w/ the n20 if you want instant and cheap, not to mention easy power
 

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Flux Capacitor is the key
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Discussion Starter · #3 ·
Are you kidding me? How about changing the axles though? Someone said some bs that you had to change the axle because it couldn't withstand the power of the SR20...thats what my real question. A 115 hp engine needs new axels for a 140hp engine because of an engine change? The tranny I can understand, but normally doesn't companies on e-bay usually sell that thing along with the engine for around 800 bucks??
 

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SR20 uses different transmission (include clutch flywheel), axles, ECU, harnesses, some of the motor mount, shifter linkage, etc...

If you have a SR20, you need a tranny made for SR20, which means your old axles will not fit on SR20 tranny. They are all different.

You said "only" 140hp, but that's as much as GA16 can go with all bolt ons. SR20 still wins because it has more low end torque. 140hp is just the starting point for SR20. You can build power and SR20 really responds to it. Great strong motor to mod on. That's why people gives so much credit on SR20s.
 

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Flux Capacitor is the key
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Discussion Starter · #5 ·
Yeah I do agree with you on the SR20 thing...according to people I hear its a kick ass engine. Iight Thanks man I'll talk to you laterz!
 

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The sr20 series has been labeled the 'most ludicrously overbuilt engine' on more than one occasion, the US version starts at 140-150 hp (depending on region/model/year, California got screwed as did a few other west coast states due to emissions and has slightly less power but that power can be made back up with the mods, the 97 200sx se-r was supposedly not even street legal in california due to emissions in stock form). But with very minor upgrades (pistons, intake, ecu and turbo...more or less) compared to most other engines you can make a japan spec edition pushing easily 230-260 crank hp and the engine will still run strong with no fear of throwing a rod or turning your crankshaft into mush (the crankshaft is rated at 500 hp max before needing upgrading and if I remember right the rods are rated well over 300 hp before needing upgrading) providing a very solid platform to upgrade as well as a very responsive engine. Also a common misinterpretation of engines is 'high horsepower = insane power'. Where this is actually true if it's done right the misconception comes from the fact that the torque is really what is moving your car but horsepower is what makes the torque (after being transfered through the engine via pistons, rods, crankshaft, differential, transmission, etc.) and the transfer of the hp to tq in the moving parts determines how efficient the engine converts it, the sr20 is probably one of the best, if not the best, small 4 cylinder for low end torque in the industry. Compare the stock numbers of the engine to something like a 2003 RSX Type-S and you'll see what I mean.

RSX Type-S engine:
(taken from www.acura.com)

Engine type 2.0-liter, DOHC i-VTEC™, 16-valve
Horsepower 200 hp @ 7400 rpm
Torque, SAE Net 142 lb.-ft. @ 6000 rpm


98 200sx se-r engine (sr20de):
(taken from www.se-r.net)

2.0 liter DOHC 16-valve 4-cylinder engine
Sequential multi-point electronic fuel injection
140 hp @ 6,400 rpm
132 ft-lbs @ 4,800 rpm

Those numbers suggest that by hp to tq alone the sr20 is almost exactly 100% more efficient in transferring horsepower (work) to torque (usable work) and it comes considerably earlier than the RSX. Those numbers for the RSX are pretty typical for most engines around that size for honda motors.

Although I can't verify it, the manual stated that my engine's specs for my 97 se-r was 150 hp, 142 torque at about the same rpm as listed above...I'm not sure exactly why the discrepancy but I'd assume it would be in the interest of the manufacturer to inflate numbers for sales.

Generally speaking though, the more cylinders the engine, the earlier, and the higher, the torque comes so this set of numbers is only fair to compare based on engine size and number of cylinders.

Ok, got a little longwinded here, heh, but anyway. The axle and transmission thing is correct. In a FWD car like a Sentra or a 200sx (90's models for US) the transmission connects to the axles. However if the car was a RWD you'd most likely only need to replace the transmission when doing the swap because the axels will connect directly to the differential which is connected to a drivetrain which is connected to the transmission. Someone with more knowledge on that correct me if I'm wrong please.

Overall, it's probably cheaper to buy an early 90's Sentra SE-R than to take an existing car and do the swap depending on how good of condition the early 90's one you'd consider buying is in. If you have tons of cash and a lot of resources and a good mechanic more than just familiar with the engine and the car then the swap isn't a bad idea, just tedious and costly.
 

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Flux Capacitor is the key
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Discussion Starter · #7 ·
HolyJesus,
Someone here knows what they talking about...lol. Cool man thanks!!! I was talking to Luispeed the other day, how about the Japanese version of the SR20DE? We could use that on the Sentra without an axle change because I think it it FWD also like the Sentra. Any mechanical engineers out there who can help us out with this hp and torque stuff for an engine also??
 

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The japanese sr20det powered cars are rwd cars (known as silvia which is just a souped up 240sx), although it's the same engine and it will fit into the engine bay of a sentra/200sx the generator, ac and alternator will probably be in the wrong place, not to mention you may have to alter the engine mounts too because the engine would be horizontally mounted in the bay when it would be set up to be mounted vertically in a rwd car. Basically it would just create more problems to work out. Now if you bought a japan spec sr20det, you could make it much easier and just buy a early 90's 240sx and rip out the slush box ka24 and stuff the new engine in, along with the appropriate transmission and ECU of course. Would take some expertise but it'll scare the hell out of the ricers.

As far as hp and tq, the only real way to alter the efficiency of the hp to tq conversion in the engine would be to bore and stroke the engine. As long as the crankshaft and rods are left alone the efficiency will always remain fairly constant unless you add more wieght to the crankshaft like by adding a supercharger (which drags on the belt that's attached to a pully on your crankshaft which leaches torque to assist in pressurizing your engine to produce more power which then produces more torque but the lost torque to run the supercharger won't be regained although you'll have a large torque gain from the power increase....confused yet?) or by changing out the gear ratio in your tranny. You can do some head porting and polishing as well but the changes in most japanese cars after those techniques is usually minimal compared to the larger american iron. Overall unless you plan on serious dragging or breaking the 300 hp at the crank mark there would be little reason to mess with the bottom end of the engine in an sr20, but people do it.

It's late, I'm tired...I hope I made some kind of sense.
 

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wes said:
ANY SR20 swap inot a GA car requires an axle swap because you have to use an SR20 transmission. ALso, not all SR20DE-T cars are RWD, there is the bluebird and GTI-R motors that can be bolted into the US FWD cars.
I found this out with the swap into a Sentra. I am in the hunt for a 200SX SE-R, but I just may have to settle with the SE or another 200. Is my info right...the SE-R is the SR20DE engine and the SE is the GA16DE engine?
 

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265k miles and counting..
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First off, a SR20DET was available in a transverse application, but never FWD. ALL trnasverse SR20DET's are AWD but will bolt to a FWD SR20DET transmission with no problems The AWD version was used in the Pulsar GTiR , Bluebird SSS and Avenir. AS for the axles, yep they are different! Jusl like you can't put a B16A into a CRX with the old D15 axles, you can't do a SR powered Sentra without the axles from a SR powered car of the same chassis designation. B13 axles are probably shorter than B14 axles and B15 axles longer etc.
 

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i pwn your mom
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if you are gonna do a swap, dont waste your tiem with and sr20de motor get an sr20det, sr16ve, sr20ve.... its pointless to swap a motor and spend 2-3k on 25 extra horses.... you can build a turbo system for cheaper
 
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