Throttle body

[38VNIT]

Who thinks this is a good buy for a throttle body.

http://cgi.ebay.com.au/Holden-VN-VS-...QQcmdZViewItem

[1991_Vn2nV]

Its not bad for the Yella Terra one. Sometimes the 70mm throttle bodies go for around $200 even on Ebay..

[YMY-88U]

yeah and some people are getting rid of v8 ones for $195

[PaRaDoX]

lol @ 10 rear wheel kw

lol silly trevor listing performance gains...

anyway this shop is awesome, they do our group buys, they're located in hallam, brought alot of things from then and WOULD buy from them again, good to deal with and cheap prices

[cbb01]

yeah why pay $195 for V8 which is only 65mm
when for an extra $70 you can get NEW yella terra at 70 mm

I went the yella terra for the extra money.
i was told to be careful with an auto aswell but no problems at all.
I LOVE THE BIGGER THROTTLE BODY
better pull off the line.

[1991_Vn2nV]

You can pick up V8 throttle bodies from wreckers for alot less than $195 though.

The Yella Terra 71mm throttle body is a good buy though

[anton1o]

65mm sells for 100$ check the mods thread for prices.

[CSL]

yeah that shops tiptop, ive purchased my intake pipe, exhaust and springs/shocks all at real nice prices.
if anyone is interested i have a big bore (69.7 i think) throttle body here for sale, 70 bucks, i bored it myself but went .2 over in the bore, so the butterfly does not make a complete seal. it's untested but i'm sure it would still work, steel butterfly. i'll get some pics up soon. pm me if interested

[Wesleyrpg]

i'd hate to upset you guys, but i have run 60mm, 65mm and 70mm Throttle bodys on the dyno run after run and it makes no difference to the power at all!!!!!! No gains, no losses, well the only loss is vacumn pressure.

[1991_Vn2nV]

i'd hate to upset you guys, but i have run 60mm, 65mm and 70mm Throttle bodys on the dyno run after run and it makes no difference to the power at all!!!!!! No gains, no losses, well the only loss is vacumn pressure.

Well other people have had gains on dyno's with larger throttle bodies and everyone notices a difference. They DO make a difference...

[anton1o]

exactly, freind made 97rwkw with cai&v8 tb.

[stockvp]

if ya got a series 2 just take out the plastic bellmouth out in between the inlet manifold and throttle body this you will definitely notice even without upgrading the throttle body

[greenfoam]

exactly, freind made 97rwkw with cai&v8 tb.

But what did he make before the CAI and TB on the same dyno on the same day, because plenty of VNs and VP have pulled 105 rwkw dead stock. The stock V6 can only breath about 380cfm of air. The stock TB flows almost 500cfm. Where's the extra power come from?

[1991_Vn2nV]

I dunno if this is right or not.. But isnt that because it only sucks in air every second rev as is a 4 stroke?

The throttle body is capable of almost 500cfm at a constant flow rate, but the engine is capable of well over 600cfm at a constant flow rate, its just that the engine only sucks in air every 2nd rev... But effectively, it is being restricted by the throttle body?

[CSL]

i dont think power can be made, the difference your feeling is all response, and they aint nothing wrong with that

[1991_Vn2nV]

Cubic Feet per Rev is perhaps a better measurement than cubic feet per minute as the engine only sucks in air every second rev, so after alot of calculations I managed to get the following figures & a headache:

3.791L = 0.13386021 cubic feet per rev maximum

63mm Throtte Body = 0.0882915957 cubic feet per rev...

71mm Throttle Body = 0.1263783741 cubic feet per rev...

But I believe after the throttle body it is restricted to 68mm at some point, so a 71mm throttle body is only going to get as much as a 68mm throttle body...

68mm = 0.1110259392 cubic feet per rev...

So I THINK they are the max flow rates for the throttle bodies, in comparison to the max flow rate for the engine. But there would be more air in the engine past the throttle body too, so the actual amount of air that the engine sucks in is higher than the max flow rate of each throttle body... But the point is a larger throttle body DOES help.

[stocky]

i wonder what the surface area of the TB opening is like compared to the original intake or the neck of the VS CAI

[greenfoam]

Cubic Feet per Rev is perhaps a better measurement than cubic feet per minute as the engine only sucks in air every second rev, so after alot of calculations I managed to get the following figures & a headache:

3.791L = 0.13386021 cubic feet per rev maximum

63mm Throtte Body = 0.0882915957 cubic feet per rev...

71mm Throttle Body = 0.1263783741 cubic feet per rev...

But I believe after the throttle body it is restricted to 68mm at some point, so a 71mm throttle body is only going to get as much as a 68mm throttle body...

68mm = 0.1110259392 cubic feet per rev...

So I THINK they are the max flow rates for the throttle bodies, in comparison to the max flow rate for the engine. But there would be more air in the engine past the throttle body too, so the actual amount of air that the engine sucks in is higher than the max flow rate of each throttle body... But the point is a larger throttle body DOES help.

Do all the crazy sums you want I'll try find you a calculator.

Ok something like this

http://www.4secondsflat.com/Carb_CFM_Calculator.html

The stock V6 has a VE of about 85% and peak revs no more than 5500

Going from a 65 mm throttle to a 70 on the 304 does give you a little 5-10rwkw increase (only in the very last 1-2000 revs) on a semi worked motor but that's an engine that breaths ALOT more air than the V6

[greenfoam]

i wonder what the surface area of the TB opening is like compared to the original intake or the neck of the VS CAI

The CAI can flow to about 170rwkw? as seen in a certain supercharged UC hatchback

[1991_Vn2nV]

Bah each to their own

I believe it makes a difference and I believe cubic feet per rev is a better way of measuring it, you believe it doesnt make a difference and that cubic feet per minute is better way of measuring it... Im not disputing the calculator because its obviously correct... Yes the engine needs 318.629 cubic feet per minute flow. But the engine only sucks in air every second rev, so I think measuring it by the amount of cubic feet of air it needs each time it sucks in compared to what the throttle body allows is a better way of measuring. But its just a difference in opinion

[VNV6VENGEANCE]

i dont think power can be made, the difference your feeling is all response, and they aint nothing wrong with that

Ultimately your correct mate. I purchased a 70mm big bore yella terra TB and did two runs on the dyno, with and without the modified TB. No kw gains were recorded. Only throttle response is altered. Anyone who has recorded gains with the TB please show me a dyno reading before and after installation

[stockvp]

what about if you take the bell mouth out and either T/B

[38VNIT]

lol iv decided scince im never gunna do head work there is no point getting a 71mm, ill prolly just get a v8 65mm, who agree's

[anton1o]

65mm good enough, 80$ cant go wrong.