supercharging z31

[mtcookson]

You can get an N/A to 300 hp with a ....load of money. Like say... for instance... the Hekimian racing VG30E. 300 hp @ 7,000 rpm and 240 ft. lb. of torque @ 5,500 for $10,500 (the price went up over 2 grand in about a year).

 

For that price I could make a turbo engine push 600+ whp easy... probably even more than that and with a lot of low end torque for friendly street driving.

 

The VG30E is not easy to make a lot of power with going normally aspirated. The reason that stock 5 liter push rod motor was making that kind of power stock was because of it displacement. When it comes to an engine being normally aspirated the saying "there's no replacement for displacement" is so very true. 300 hp out of a 5 liter push rod engine is kind of weak though. My Nissan 4.5 liter V8 makes about 305 hp stock.

 

Anyways... "abnormal hp numbers" when non-N/A?? Horsepower is simply a function of torque and rpm. (Torque x RPM) / 5252. When going with forced induction you get much more low end torque. What exactly do you mean by "abnormal hp numbers"??

[Guest ZFury]

Basicly HP numbers not really obtainable through natural aspiration. Is what I mean by "abnormal".

 

It shouldnt cost a load of money to get an NA over 300hp. It should be able to be obtain with the stock motor. And if for some reason it wasnt, all you should need is a cam.

[mtcookson]

I hope you aren't talking about the stock VG30E making 300 hp normally aspirated. If you can make a VG30E make 300 hp normally aspirated stock with a cam... you would most certainly have to be God himself.

 

You would first need pistons. Custom pistons since no one makes any for the VG30E in high compression. Minimum $600 from BRC Performance.

 

JWT's biggest possible cam - $560

 

Upgraded valve springs (for the higher rpm that you'll need) - $129

 

Port and polish

Valves

Maybe even lighter rods

Modified intake and exhaust

Etc. etc. etc.

 

Going by the price of the pistons, cams, and springs alone I could have already had a turbo setup making at the very least 250 whp and probably over 300 ft. lb. of torque.

 

You're probably barely pushing 250 bhp with the N/A mods I listed. It would take a lot of money to get a VG30E to 300 hp normally aspirated. The same money put into a turbo setup would yield more power throughout the entire rev range and you wouldn't have to drive it like an S2000 to make decent power.

[Guest ZFury]

eh' I figure with a new stand-alone ECU and an adjustable FMU you could get it in the 300hp range (with unrestricted intake and exhaust). With cam work you should be able to get way over.

 

When I put an adjustable FMU on my car that has unresticted intake and exhaust. The more I increased the pressure, the more power it just kept getting. But finally I started reaching the limits of the stock fuel map and it started loading up in the low RPMs with unburned fuel. Wish I had my MSD box on then... or a working piggy-back unit atleast.

[mtcookson]

A VG30E will never make in the 300 hp range with ecu, fuel, and cam mods. 200... possibly. At the very most, maybe 250. Not very likely at all though.

 

You might get that much with a rotary cam swap... but you're probably looking at $10,000 for that.

 

Its simply impossible to get a lot of power out of a VG30E normally aspirated without a lot of money. Even then, you're very limited. That $10,500 engine makes 300 hp. Like I said, with that money going turbo you could easily make double that... probably more.

 

On a VG30E with an unrestricted intake and exhaust the chances of you bringing the volumetric efficiency up high enough to make a big difference in power would be slim.

 

The best flowing intake and exhaust might get you 20 hp... 30 if you had the worst stock intake and exhaust on earth... but considering Nissan makes very good stock manifolds and such, not likely.

 

With good fuel tuning you would maybe see another 10 hp or so... more if the initial tune is really bad.

 

Nissan actually tends to run their maps a bit rich so if you were going normally aspirated you would increase power a bit by running their stock maps a bit leaner. Unless the mods you added allowed enough extra air to go through to cause a very lean condition, turning up the pressure won't increase power. N/A engines tend to run better when the fuel is closer to stoich. That's why when you see BSFC calculations N/A engines are around .5 while boosted upwards of .65.

 

I could go on, but shouldn't have to.

[titaniumbmx]

the project looked too much like work so i just bought an 87 turbo. thanks for all the input anyway:?