"80CobraKid" (80cobrakid)
10/17/2013 at 02:26 • Filed to: random thoughts

I think I'll DD a RB25DE powered Kouki S14 in the future. Yeah.

DISCUSSION (14)

PanchoVilleneuve ST > 80CobraKid
10/17/2013 at 03:50

Any reason why you're going RB25DE over RB20DET?

GhostZ > 80CobraKid
10/17/2013 at 04:36

Kinja'd!!!

There's an S14 with a Kouki front end conversion who parks near me, and looks pretty close to this. I doubt the engine has been swapped, but they look great. I approve of your choice.

Just make sure when you're doing with the 3V KA24DE, you find something else good that it will go in. Those motors are a lot better than the previous-gen KA24E.

GhostZ > PanchoVilleneuve ST
10/17/2013 at 04:37

An RB25DE will make about as much power as an RB20DET, but cost just as much (probably more) than an RB25DE to swap in, and is significantly worse long-term if you plan to build up the engine.

If he's choosing the RB25DE to stay N/A, then its a no-brainer and the RB20DET wouldn't work.

If he's choosing the RB25DET (and just didn't specify the turbo) for the big power, the RB20DET is insufficient and offers no cost advantages for the reduced power.

I personally am a bit fan of 3-Valve KA24DET builds. For the cost of an RB engine swap, you can make the stock KA engine make 250-300HP. The downside is that after the 350HP mark, it's basically custom-only work and you're left without any high-performance aftermarket. Compare that to a 250HP RB25DET that costs as much as a KA24DET built, but will take you up to 400-450HP relatively easily and safely.

PanchoVilleneuve ST > GhostZ
10/17/2013 at 05:09

Turbocharged KAs are great, and the aftermarket has been doing them long enough, and doing them well enough, that it almost seems silly to drop in an SR20DET.

GhostZ > PanchoVilleneuve ST
10/17/2013 at 05:15

The only reason to drop in an SR20 is if your original engine blew, or you got a really good deal on an SR20DE out of a Sentra SE-R and a longitudinal transmission mounting kit.

My only beef with the KA is that the bore has really no opportunity to be widened (unlike RB engines, with more cylinder wall and more weight) and the stroke is so long that high-RPMs are very hard to reach. That's why they're actually pretty good drift engines, because they get consistent low-end torque, but their configuration isn't conducive to high-HP. From what I've seen, building them is like you're fighting against the engine's shortcomings rather than augmenting its best parts.

80CobraKid > PanchoVilleneuve ST
10/17/2013 at 11:15

N/A, reliability, dat sound. I would have it at around 300 HP. Keep it simple.

80CobraKid > GhostZ
10/17/2013 at 15:47

I've seen pictures of that car. That is EXACTLY how I'd want it, except blue or metallic gray with vintage gold gloss plastidipped wheels. CR Kais look right at home on them.

GhostZ > 80CobraKid
10/17/2013 at 23:53

If that's the case, stroke that engine to an RB30. With 2.5liters, on street gas you'll need about 10000RPM to pull 300HP. (and even on racing fuel and 14:1 compression, you'll still need 9000rpm) If you stroke it (and thus not require you needing a new valvetrain) to 3.0liters, you can make the same power at 8500RPM, a much more reasonable amount, and 7500 rpm if you use higher compression and higher octane fuel. These are conservative estimates though, you could probably pull it higher (less RPM or more HP) without turbos if you dumped enough money into it.

There's a rather famous 240z by Rocky Auto that features an N/A ITB RB30DE. It's on carbs and race fuel, I believe, and pulls some incredible power numbers. Check it out here:

http://www.speedhunters.com/2013/02/modern…

Australia may be your saving grace to finding people who know how to build, he event when the Aussie parts route for that car.

80CobraKid > GhostZ
10/18/2013 at 00:25

Thanks for the info! ITB and EFI would be the way to go for me, and if it had to run on premium that would be fine.

I did a little research on the RB engines, and I've heard about the RB25 NEO. Is that N/A or Turbo? And honestly, what would be the best DD RB engine configuration? This is all for future knowledge for me. I haven't even finished my Mustang yet, and I'm already planning this project (albeit a lot simpler).

GhostZ > 80CobraKid
10/18/2013 at 00:40

The NEO was a re-designed tuned port intake system for the RB25. It was offered in both N/A and Turbo options, and it was on a number of other Nissan engines. On the SR engines, it was combined with Variable valve timing to get some insane HP/liter configurations (like 175HP out of 1.6l). Basically, they emulated Honda's tech on stronger engines, so they got the same HP/displacement, but at lower RPMs.

It was done mostly to reduce emissions, but they improved the camshaft and a number of intake components that made it quite a bit stronger.

The best DD RB engine configuration would be a stock RB25 with a little more boost (~320HP).

80CobraKid > GhostZ
10/18/2013 at 00:44

Good info!

Goals:

Nice condition 97-98 S14 (Could do earlier+nose swap) what model as the black lower chin spoiler?

RB25DE or T NEO

Work CR Kai in Gold

GhostZ > 80CobraKid
10/18/2013 at 00:53

Nice condition 97-98 S14 or earlier+nose swap: $7000

RB25DE/T NEO + restoration work + mounts: $10,000

Transmission + differential + driveshaft swap + mounts: $5000

Wheels: $1500

Not sure about the black spoiler, but you'll probably be able to find an aftermarket one easily.

80CobraKid > GhostZ
10/18/2013 at 23:37

Ouch. That hurt more than I thought it would. Maybe I'd start with just the car and wheels and work from there. Lol.

GhostZ > 80CobraKid
10/19/2013 at 04:22

RB engines are not cheap, and neither are nose swaps. Going SR20DET or KA24DET is about 70% of the performance (or 50% if you're willing to seriously build the RB) but at 20% of the cost, especially since they basically drop in. The RB needs a completely new transmission and mounts.

I'm not saying it's not possible, and you can do it cheaper, but those are realistic numbers from what I've seen. Still cheaper than a new Camry.

What you need is to find someone else who is selling one they built, like this one:

http://www.jdmchicago.com/forums/showthr…