4dscPat

How high can a VG safely rev? I know I probably wouldnt make much power up high, Im just curious as to how high they can safely go, completely stock. I was looking through my Haynes and noted the forged rods and wondered why the factory redline is so low.

DanNY

iTrader: (14)

low compared to what?

motorcycle?
honda vtec motor?

Matt93SE

iTrader: (44)

bone stock, they have a rev limiter at 6200 for a reason. there's no power up there, but the internals aren't going to fly apart... yet.

with the JWT ecu, they raise the limiter to 7000 and there's still power up there, but only with mods.. to go any higher than that, it's time to start replacing valve springs and cams.

mtcookson

iTrader: (2)

probably most newer v6's and even a few v8's (infiniti 4.5 liter v8 that i got out of a 90 q45 - 7000 rpm redline). it does seem a bit low compared to some of the engines during the same model year but that would be because it was introduced in 84 and not much changed on it.

i've heard the engines can handle 7000 rpm pretty well... i just wouldn't be there all day. i believe jwt reprograms their ecu's to hit 7000 rpm on the vg.

KRMaxima21

I have the ECU with all the mods for the VG and my rev limit is 7.5K. I revved it up there once but never did it again because I like my car.

maximagxe90

Hi,

probably the redline on the v6 vq is at the 7,000 rpm mark,

that the 4gen and 5gen that iam talking about,

Matt93SE

iTrader: (44)

Hmm.. funny. have you ever LOOKED at a VQ's tach?

maximagxe90

no i have not look at a vq tach before,

anaximander

iTrader: (1)

There's this formula to compute potential speed through rpm's. If the car is going 130mph at 4k, how much more mph is left in the engine?

maximase86

iTrader: (24)

Yeah, VG SOHC's, 7k seems to be about the limit...but very few VG's have anything up top considering it's more of a low-mid end range motor.

S

4dscPat

Assuming a max of 6200rpm
4k divided by 130 is about 30.8 RPM/1 MPH

6200/30.8 would give about 201mph. Of course, there is no way a VG would have enough torque to overcome the air resistance at that speed. Air resistance increases exponentially with speed, so it would take alot of power.

My VG seems to max out at around 130mph. It has plenty more left on the tach, but it just dosnt have the torque to overcome any more drag.

longpole938

somethings wrong w/ my VE then... it runs outa juice at 125 (only done it once to test it out)

-shock211-

iTrader: (1)

10chars

mtcookson

iTrader: (2)

until turboed. then they are monsters up top.

longpole938

do the VEs rev differnt cuz mine deffently goes to 6600

JohnnyWash1

Yup. DOHC vs SOHC, performance vs driveability/reliability. The VE was made to go fast, so high end power had to be obtained if displacement wasn't changing (between the VG and VE).

maximase86

iTrader: (24)

Well you can do it too N/A'ed. Heimekian Racing makes a VG that makes 300hp, and like 240ishtq up around 7k-7200rpm. However, the motor is not streetable.....well it is, but...well the driveability would totally suck. Plus the motor is $9k........that's a lot for only 300hp.

S

mtcookson

iTrader: (2)

yeah, i think that going turbo would be much better than their n/a engine. at 300 hp i would be making a hell of a lot more torque and much earlier in the rpm's. possible the only advantage that engine would have would be on an autocross... but i'm unsure.

floods943

About how much gains are you experiencing with your turbo VG? I'm sure you've been asked this many times before, but I haven't been here all to long