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SR20 or RB


Guest Anonymous

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I believe the 1JZ turbos will hold you back from hitting 500RWHP. The motor IS capable of that without internal mods but those turbos are ceramic and boost limited. They also have ZERO lag. Finding single conversions for gthe 1JZ in the states isn't easy so you'll be fabbing or paying for fabbing most likely. I could be wrong though - the www.i-supra.com WEB site has a 1JZ section where you could find out more answers.

 

A JDM 2JZ motor can be gotten faily cheaply - under $4k and probably under $3K. It's got crappy turbos too and small injectors but you'll be dumping that anyway. Cams are supposedly smaller as well but stock cams can be gotten somewhat easily as Supra owners upgrade. Single upgrade kits for the Supra have been DROPPING in price lately. :eek: Seems all of the shops have picked up on the budget minded consumer and are fighting for their business - this naturally started AFTER I'd bought my single :rolleyes: Kits capable of over 600RWHP can be had for less than $3800. At this time at least 4 shops are either offering them or are selling them. Fuel would best be sourced in pieces from someplace like Garageadvance.com - who also has a budget turbo kit out now ;) Just get a rail, spacers, and standoffs - maybe injectors - from them. The rest of what they've got for the Supra wouldn't be needed.

 

Honestly - I thought the RB motors could make power like the JZ series without internal mods. I'm kind of dissapointed to hear that's not so. I've admired those motors for some time - the SR motors too. I think a 240SX with an SR swap would be a blast to drive! :D

 

P.S. 3700lb Supra are capable of daily driven 10 second 1/4s. I know someone who owns one and when mine hits the track I hope to be deep into the 11s - 10s I'd faint. That's pushing over 550RWHP and a little over 600RWHP on race gas. Drop that monster in a less than 3Klb Z hail.gif As it stands now I can toast the tires from a roll in 3rd, possibly 4th. These are 275 555s and I may go back to DRs. I'd love to do this swap!

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Guest Anonymous

Hey, i have run 11.063@126.31 . i agree with Bob in that putting a low 11 sec car together for 5k is not very realistic.I have tremendous respect for the hp of my car and i wanted a fairly enonomical car to boot. So a fairly low boost (9psi)on the street and a big shot of nitrous for the track is my formula for success. I think a low 12 sec street 240 could be built on a buget using a L-28 with carbs and a port nitrous system if a guy watched e-bay closely and put his money in the right places.

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Originally posted by BLKMGK:

Honestly - I thought the RB motors could make power like the JZ series without internal mods. I'm kind of dissapointed to hear that's not so. I've admired those motors for some time - the SR motors too. I think a 240SX with an SR swap would be a blast to drive! :D

The RB-series engines really don't match up to the JZ family, in my opinion smile.gif The RB20 has low compression (8.5:1) stock, but is held back by its low displacement. A shop on the east coast of australia has squeezed 200rwkw out of an unopened block with a lot of boltons, but it hasn't got much more in it. The RB25 is a great street motor with its higher (9.0:1) compression giving good bottom end torque and spool, but ultimately restricting it boost-wise. Unopened, they're good for ~240rwkw with good tuning and a lot of boltons, and with a thicker HG I think the level raises to around 280rwkw. The weak link is the pistons, but upgrading them only raises the bar 10-15rwkw before you risk something else breaking. The RB26 holds the most power for an unopened RB-family engine, but even then it pales next to the 1JZ. It does, however, have extremely good aftermarket support. On the down side, everything even slightly-GTR has a huge price tag.

 

JZ's, on the other hand.. seem to be cheaper yet more capable. I think this is a spinoff from the massive hype the GTR gets as the greatest car ever. Similar thing for honda engines - the $/hp ratio is rediculous. To some extent, this is true for the SR's - and I've been saying this for a while smile.gif - It seems that the SR20 has a reputation in the US similar to the RB26. They're good, but not unbelieveable. And we get your 240SX's (our 200SX) in Australia with SR20DET's standard tongue.gif

 

It cuts the other way - you guys have eleventy billion SBC's and BBC's in america, but they're relatively rare here so they probably command a bit more respect than they deserve...

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Well I'm going to respond to the VG30ET engine route, as I can attest to "been there done that"

 

NO way you can build 500hp for less than $5k.. MAYBE you'd come close if you did ALL the assembly/rebuild work.

 

I know.. I just finished my motor. way over $8K, and I did not build the motor myself.

Yes you can buy a cheap low mileage block and do it up.. but i'd hardly trust a $5k investment in a USED engine with an unknown past. I had all my parts machined, balanced, polished etc...new parts where needed. Reliablility is a huge factor at the 500hp level... in other words..things need to be perfect...

 

I also agree with Scottie FULLY on the part of spending BIG $$$$$$ on the rest of the car. 500hp WILL KILL YOU AND YOUR Z. This is FACT brakes are critical, so is a cage, so are lsds, stronger halfshafts etc.. you will break things in a hurry.

Too many people driving Z's into the 12's in which the rest of the car is near stock.. WAY TOO SCARY.

 

I'd also be quick to challenge most Z owners truely being able to handle a 500hp Z. down a straight line is one thing.. on the street is a whole other ballgame.. rain, other cars, kids etc...

 

$5K on motor (you do all work)

$5K on brakes, suspension

$1K on cage, harnesses etc....

Plus another $2K for miscellanious breakage (they are at least 25yr old cars now)

 

Now your talking realistic attainable goals..

 

Account for another $5k if you are not able to, or have time to do a lot of the work.

 

Now thats more real.

Just my 0.2 cents (14yrs Z experience)

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  • 2 months later...
Guest Anonymous

I've been reading these posts, and have come to the conclusion/assumption that your not nessesarily looking for a 500hp car, but rather, an 11 second car. There are other ways of reaching this goal than achieving 500hp, and may keep you in budget... Maybe. You might concider finding ways to shave weight off your ride so your motor won't have to work as hard. You might start by making molds from body panels, such as fenders, hood, door skins, ect. Fiberglass may be cheaper than hourse power... Cheaper than 500hp anyways. And if it's not gonna be a chicker picker upper, you could ditch the passenger seat ant other interior components. After that, bust out with the hacksaw. aerodynanics are another factor; I've heard Z's have a terrible drag coefficiency, so you should look into body kits. As far as inexpensive, yet powerful and reliable Nissan motors are concerned, a ca18det is an iron block and will fair better than an sr20; still... Powerful and reliable? And $5k? Then there's the Infinity 4.5L V8--I'm not sure the engine code--witch would give you 260hp to start with, and lots of torque, and cheap too. And a 6-speed from a Z32 TT supposedly bolts right up.

 

Well, thats about all the advice I can give... best of luck to ya!

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Guest Anonymous

Forgot to mention, these guys are right; every car should be able to stop quicker that it accelerates. Brakes are not an option, there a MUST HAVE!!

Also, you'll definitely want a roll cage, not only for safety, but also for rigidness, especially if you do decide to cut weight by hacking away at the cars frail unibody structure. And, if you're lucky enough to find one at a junkyard, the '87 through '89 z31 turbos came with a 3.74 lsd recognizable by its finned housing. Some 240sx's also had a r200 diff. with a finned housing, but do not be fooled; they'er not lsd.

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Guest empracing

ill probably get hammered here but i got a vg30det (yes a quad cam vg30 with single turbo) in the shed and well should i continue... 500hp not at the moment but you ever hear of second hand turbos? ps try au$500 for the motor just got a problem with gearbox selection

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Guest Anonymous

Man, I'm getting a deal on an rb20det... Comes with everything, and cheap enough to get it into the car for less than said price and have plenty to spend on bolt-ons. Not 500hp, ofcourse, but keep in mind what I said about weight reduction and aero physics, if you want to call it that. I'm not trying to give any advise here; just braggin' about the deal I'm getting.

 

Too bad I'm pushing a zx... Someday I'll get a 240... Someday

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one thing i know, is that the only way im even coming close to 500hp for 5k is by using my best resources-American drivelines. RB or SR o get those power levels requires way more than a5k to even get the motor in a body and drive to the store. i wont do a 1jz either, too exotic, any rb series motor too much for me as well. shoot, the way i see things, my L28et is even getting too expensive for me-Standalone managment for 300hp can, well i cant say it on line, but ill say thats real crappy hp to $ return in my eyes-but the best of any of the other motors in terms of hp to $ spent because it bolts right in, while the other ones usually need a standalone management, or a blackbelt in Kanji! if you really want the recognition and the glory, go for it. my choice, that Buick 3.8 sfi turbo with a 2004r-and thats my choice after looking at almost every option.

i know a lot of guys with hands on knowledge of the turbo buick, and one crazy guy down the way from me has a tt lt1 in his t type-single digit killer.

500hp is crazy in a zcar, and will take some crazy brakes, and respect of that power under your foot. if i get my car to this level, im pulling the IRS. no funny cv shafts, no stub axles, none of that, cut out the middleman like they say. out of it completely, I dont like AUTOX and i only take a turn hard to get sideways . In goes a 9" with a four link and big discs, a race car that can drive on the street just fine, and pull both wheels up about two feet! I have come to learn i really dont like stiff driving cars, i actually like my worn out shocks and springs 280z more than my full coilover and sway barred v8240z-by a huge huge margin..

i might change the shocks and springs out to nice stocker units at the most at that level of power, i think suspension only really comes into play when you are trying to have the best of both worlds, drag and auto x, and being somewhat ok at both. if i have my pick-its drag racing, nobody is gonna jump out of their car at the light and line up the cones and challenge you to a slalom.

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Guest Anonymous

I'm not shootin' for 500hp, really; 300-350hp is my goal for the time being.

Two things I need, though, are motor mounts and an ECU. I know I'll have to source those from Japan--unless someone has a set for sale? I need to no where to get an ECU, though. I've searched the 'Yahoo Japan' auctions, but couldn't find any. Haven't looked in E-bay yet... Will an rb25det ECU work? What's a decent price for an ECU? Does anyone know a good place to look for this stuff?

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Guest Anonymous

Hey Brad, I think I pm'd you by mistake. I want to get this out to anyone reading this; I'm looking for 200zr motor mounts, preferably JDM factory, but fab. is O.K. too...

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The mounts I make are for my RB26. Bob H and I both use them. They use the stock 240Z rubber mounts. I do not know if they will bolt up to a RB20DET, but 200zr mounts also bolt up to the RB26 so it should work.

My mounts put the motor lower and farther back then the zr200 mounts, better performance.

 

I give people 3 options with my mounts.

 

1. I give them ready to go mounts for 100$

 

2. I give them the laser cut flanges that bolt up to the motor and the crossmember, and they can use them to make mounts for 40$

 

3. I give them the AutoCAD file for free, and they can give the file to a laser cutter in their area to get the flanges cut.

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Guest Anonymous

Thats cool! Now I have a source for motor mounts. I'll not be needing them now, but hopefully in the near future.

 

One thing tha's concerning me, though, is tranny placement. I've heard the rb25 missions are easier to fit than the rb20's, which is what I'm getting with the motor. I'm guessing you have the rb25 mission. I'm wondering, though, how your motor mounts effect the position of the shifter. I understand that's a troublesome area when fitting an rb, but I would imagine you designed your mounts with that in mind, but let me know, please. And any info on fitting an rb20 mission would be very helpful.

 

Notice I'm using the word "mission" instead of "tranny"... I'm setting a new trend; Jap style, YEAH!!

 

That reminds me; check out this site... You might have to use alta vista to translate...

 

http://www.rockyauto.co.jp

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  • 1 month later...

I wonder when people say that the RB20 and the 25 can not hold much power. There were many people that said the RB26 could not keep up with the 2JZ engines. Mike Ferrara, owner of Drag Sport Magazine has made 760 HP to the wheels in his R33 Skyline. The RB26DETT in his car is untouched. Of course he has upgraded APEXi turbos and a monster fuel system.

 

I am curious to see just how much HP the RB20 can handle before flying apart. I think that with proper tuning they can get more than expected. Just like the Buick LC2 engine. With more precise tuning and parts, folks are putting the stock block in the 9s with repeated reliability. ERIC. :D

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