70mm Commodore Throttle Bodies!!!

[anton1o]

v8 65mm does a good enough job!

 

[mouce]

and i think it actually means the airflow is 31%
better(less restrictive?) than the 60mm

Even if that's the case, every simulation I've ever seen shows that the stock VN V6 motor doesn't max out the max flowrate of the stock t/b at WOT.

Sure at lower throttle percentages the response will feel more lively but there's no increase in max power.

 

[Boonz]

really it just means you dont have to fully open the throttle to let the same amount of air in as a stock T/B...
how come the TPS doesnt give an incorrect reading to the ecu as it thinks its letting in less air than it really is????

 

[pandaman]

really it just means you dont have to fully open the throttle to let the same amount of air in as a stock T/B...
how come the TPS doesnt give an incorrect reading to the ecu as it thinks its letting in less air than it really is????

Actually, doesn't matter too much really, the fuel maps specify an AFR versus MAP and RPM not a specific amount of fuel, the computer works out AFR's from the O2 sensor reading and supply's the appropriate amount of fuel.

 

[greenfoam]

The ecu only adjusts the fuel ratio from the O2 sensor when its at 14.7:1 on the fuel map anything other than that is a calculation based what the map sensor is reading, the rpm, the injector size the VE table and a few other things. Still the point is that the throttle body for a stock or bolt on V6 is plenty big enough allready. You only need a bigger one on a good 304 and even then it's not a big gain unless it's a pretty serious motor

 

[pandaman]

The ecu only adjusts the fuel ratio from the O2 sensor when its at 14.7:1 on the fuel map anything other than that is a calculation based what the map sensor is reading, the rpm, the injector size the VE table and a few other things. Still the point is that the throttle body for a stock or bolt on V6 is plenty big enough allready. You only need a bigger one on a good 304 and even then it's not a big gain unless it's a pretty serious motor

Ah right, thats making a lot more sense now, I was wondering how a narrow band 02 sensor could possibly work like that. But my point is that a larger throttle body wont stuff things up, it wont make the engine perform worse. I agree that a larger throttle body wont make much (if any) improvement, but there's no harm in chucking one on if future mods are planned. Apparently you can even gain a couple of kilowatts at the top end on a stock 5L by using a 70mm throttle body, but it's only top end that changes. You can simulate all you like but the real world results don't always match nicely.

 

[kasey375]

Hi. If any one want a 70mm throttle boddy i wold be getting one from here
http://cgi.ebay.com.au/VN-V6-V8-THROTTLE-BODY-70mm-with-tps-idle-solinoid_W0QQitemZ270035082181QQihZ017QQcategoryZ102360QQrdZ1QQcmdZViewItem
These are very a very good throttle body and he will do them cheaper than any one else.

 

[greenfoam]

Ah right, thats making a lot more sense now, I was wondering how a narrow band 02 sensor could possibly work like that. But my point is that a larger throttle body wont stuff things up, it wont make the engine perform worse. I agree that a larger throttle body wont make much (if any) improvement, but there's no harm in chucking one on if future mods are planned. Apparently you can even gain a couple of kilowatts at the top end on a stock 5L by using a 70mm throttle body, but it's only top end that changes. You can simulate all you like but the real world results don't always match nicely.

Yeah you can gain a few kw on a stock 5 liter but not on a stock v6. But it makes sense you could gain 5 rwkw on v6 with a big cam and ported heads if you were going that far with the engine, weslyrpg tested his bolt on V6 back to back with the stock throttle body and a big one and made exactly the same power on both runs

 

[AlpineRaven]

Can it be done at home job? I have an lathe here and would it work?
Cheers
AP

 

[andrewownsavp]

be cheap and take the throttle body restricter out and money else where could be more useful