Swap ideas for 1970

[Gollum]

Well if you're considering the VG you've probably already seen all these dynos, but Jason's dyno looks like this:

 

 

 

He put a bit of work into an in-home garage porting job, using Ferra valves and schneider cams. Other than a non-stock turbo other than that the rest of the mods are all about fuel and how it's delivered. It's amazing what some people have gotten from stock bottom ends.

 

 

I personally like how these motors make power. Some say they're worthless as their heads don't flow enough, and that's partly true, but that's why they make such a flat HP curve. The VQ will make more power much more readily, but it will be much more linear without so much torque fall off at the top. Of course torque really isn't an "issue" in an force induced build, but it's a difference that's worth considering.

 

The L28ET CAN make 500hp, and isn't unreasonable when the correct work as been put into it. Of the nissan options it IS one of the more difficult options, mostly because it's just the road less traveled and will require attention to detail (which is true in any case you're almost tripling stock NA HP).

 

The SR isn't a terrible option. Seems like many of them pop around 400whp but of course i'm sure it comes down to tuning. There's people that reach well beyond 500hp, and some say 500hp is capable on stock pistons, which seems dicey to me, but then again I'm not the one building SRs, so what do I know?

 

The KA is about as capable as the SR when it comes to brute power, but of course the way it makes power is very different. almost half a liter more, head that will flow for the displacement, but a crank that doesn't want to rev high. One main downside is that the stock internals aren't quite as capable from what I've seen, and you're buying more parts out of the box but from what I've seen they're not really more expensive to build than SRs.

 

The RB seems like the logical choice if you want it nissan and want it easy. More needs to be said?

 

The road much less traveled that I'd love to see more of are the nissan V8's. The VH is plentiful and there's already manual trans conversion kits out on the market. Great motor but for your "goals" force induction is definitely a must, so you'll be making a custom setup no matter what. Same pretty much goes for the VK series, unless you can get your hands on a GT-1 racing motor.

 

 

And onto the much more important side of this topic... Stock 240Z should weigh in around 2350 or so, but let's call it 2500 and FAT for a S30. Maybe you've added weight in the brakes and wheels, and put in a cage without removing a dime of weight... Even at that weight you're in the power to weight range that you're talking about a 675hp viper, a 825hp modern dodge challenger, or a 640hp 350Z...

 

And that's all IF you make it heavy as a pig for a 240Z. AND that's IF you go with "only" 500hp. At 600hp and a realistic 2400lbs then you'd have a better power to weight ratio than a Veyron, and that's CRANK hp... So 500whp you're already at the top of super car power/weight ratio.

 

My "heavy" 280Z which is much more difficult to remove weight in is already under 2500 pounds and that's still with a steel hood, full glass, and the big R200. I plan on running it without side glass, rear lexan, and a composite hood. Even with wider rims/tires I still expect to be well under 2400 pounds when I'm done. If I had a 240Z like you I'd be considering doing the subie R180 swap for a bulletproof LSD diff that will save more weight over the LSD R200 options.

 

Personally, I'd recommend you shoot for 2200 pounds and 350whp, which should give you well over 400bhp and land you in a power/weight ratio that's still deathly fast. The beauty of those more realistic goals is that it really opens your world up as far as engine options. Now you can consider a NA VK either with some minor NA mods or the new direct injection version with 400hp stock. Now your turbo builds look MUCH more affordable as the main things that will need attention is the fuel system/ECU, not too much else. Now you're not looking at requiring a 275+ rear tire in a racing compound in order to get traction in 3rd gear... Now you could live without flaring the wheel well if you didn't want to.

 

You mentioned wanting to do AutoX events, and no matter what with more than 300hp you're talking about a car that will be a SERIOUS handful any autoX event. Most of the cars there will have more than DOUBLE the weight for the HP. And remember, power/weight is rarely the main factor that determines weather a car is fast on a tight course like that. Even on faster road courses like Laguna Seca that still doesn't have much in the way of long straights pure power/weight isn't the winning key. It helps, and is a factor, but that's it.

Edited February 22, 2012 by Gollum

[Nismodealer]

Fantastic post. A lot of great info to consider.

 

The only thing I keep revisiting is how badly I want t kep it all z. Any v8 swap would clearly do the trick, but I really want to stay faithful. I realize the power to weight theory well, which is one of the reasons I selected this car ( my 93 rx7 was comparable at 428 rwhp).

 

If there was a conversion kit for the vg30dett I'd buy it tomorrow, but I'm still researching heavily. I'd feel a bit more comfy with something more explored, but we'll see.

[richracing]

I was considering doing a vg30dett swap also before I decided on the RB. What I was going to do was use Mckinney SR20 swap engine crossmember, and VG30/240sx swap mounts from Xcessive. In theory, that would work just fine.

[MazterDizazter]

The RB seems to be the best way to go if you want to stay Nissan, make 5-600hp and not modify internals. I don't know what the dimensions of the 240Z engine bay are relative to the 300ZX TT but the VG30DETT is cramped as-can-be inside the 300ZX. RB Z's make wacky power and look like they're easy enough to work on. There's tons of bolt-ons available thanks to massive support from Skyline tuners. The RB25DET would be less money and work because it comes with a RWD gearbox and oil pan, whereas the RB26DETT is as you know, all-wheel-drive only and has a front sump oil pan.

 

I'm going L28ET with a Z32 gearbox and Z31 LSD, but it'll need internal work to break the 400hp barrier safely and reliably. People have made 4-500 on junkyard motors but I can't say I'd trust them to make that power all day long. I picked up two engines for $500 each and they bolt right in; the money saved over an RB and mounts can be spent on internal work, turbo upgrade and standalone EMS. If you can source a V07 Diesel Maxima crankshaft (LD28) it bumps displacement to 3.0L with 240Z rods (They go for around $4-500 when they pop up). The L28ET is a dinosaur of a motor though; it's a single cam, non-crossflow head that flows like crap compared to modern twin-cam engines. A heavily worked-over L28ET head still flows worse than a stock KA24DE head. But they make gobs of torque and sound mean as hell!

 

Here's a video of a 607whp 280Z running a turbo L-series on pump gas:

Edited February 23, 2012 by MazterDizazter

[Nismodealer]

Honestly, after the quantity of research I've Been doing, I think I'm going to go with that identical setup. I've planned on rebuilding the motor so the l28 seems most convenient and will get me where I want to be. Ive always liked total seal for rings, but will be sourcing out forged internals and the drivetrain starting now. Unless of course someone wants to start listing out their preferences here...

Honestly this forum is awesome. Everyone's input has been great. I've spent a lot of time on other forums and the rx7 forum was practically the worst. People are very secretive about what they do, but this place is just up front and honest.

 

Again, anyone reading these threads is more then welcome to email me about getting a great deal on factory parts, as Im advisor at Future Nissan in NorCal. It may take me a few days but Ill get back to you. I'm working on setting up a big discount plan for forum members but for now I can get whatever at probably half of what your local dealership can.

 

Good input on the powertrain to support. I'll probably steal that idea.