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Madness
P Plater
22 Posts
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 Posted - 17 Sep 2006 : 4:29:53 PM
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With all the talk on ensuring the throttle body opens 100%, i just want your thoughts on installing a larger throttle body (bored out to 70mm instead of standard 60mm, which makes the opeing 30% bigger).
My thinking is that its just like installing a better air filter and cold air intake, allowing for more airflow, improving performance.
Also, will the standard fuel pump and injectors handle the increased amount of air.
Thanks
Matt
91 VN V6 Auto
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mouce
National Driver
1525 Posts
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Posted - 19 Sep 2006 : 8:51:48 PM
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First up be very careful using percentages. Without doing some rather interesting maths, you can't give a percentage increase figure for the size of the opening.
Bolting up a 70mm t/b won't be an issue. It should just go straight on. By the same token, a V8 t/b will bolt straight on too.
The reason for fitting a larger t/b has nothing to do with the amount of air that can flow through it, as the Stock V6 motor will never max out the stock t/b.
The reason that a larger t/b 'feels' more powerful is that at low throttle openings the opening is larger allowing a higher air flow at low throttle percentages. At anything past approximately 30-40% throttle opeing, you'll not see the difference between a larger one and a stock one.
Fitting the better air filter allows the engine to suck air in more easily, meaning that less power goes to 'sucking' and more power goes to driving.
The CAI is to allow the engine to breathe cold air. Cold air is more dense, the more dense the air is the more O2 there is per volume of air. The more O2 that goes into the cylinder, the bigger the bang.
The standard fuel pump and injectors won't have any problems at all with a larger t/b. Nor will it have any problems if you want a larger t/b with a CAI and hi-flow air filter. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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trizo
Forum Moderator
3091 Posts
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Posted - 19 Sep 2006 : 9:44:37 PM
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| wat type cai is recomended I'v heard alot of people usin the vs cai? |
3 can keep a secret if 2 are dead |
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Madness
P Plater
22 Posts
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Posted - 19 Sep 2006 : 11:24:09 PM
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So... pretty much, the bigger throttle body just means i dont have to press the accelerator as much. No real gain in performance.
Im using a vs v6 superchared cai, personally, I did not notice any difference from this mod(never timed myself before), along with k&n fillter. However without the filter (forgot to put it in once), i'd get little chirpies off the line.
The holden one costs about $60, the SS inductions one costs about $230 and looks like it has a bigger opening.
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mouce
National Driver
1525 Posts
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Posted - 20 Sep 2006 : 10:34:54 AM
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There's bugger all difference between the VS s/c CAI, and the SS inductions CAI (other than the price). The one from the VS is the way to go.
With the larger throttle body, you'll have a slightly more lively throttle response at low openings, so it will feel a bit more powerful, but in reality max power is still the same. As for getting it to chirp off the line, you should be able to do that even with a paper filter and no CAI. The VN produces enough torque to chip just about anything up to and including 235 tyres from a standing start. If you can't do it normally then you're down on power/torque for some reason. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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Madness
P Plater
22 Posts
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Posted - 20 Sep 2006 : 5:43:47 PM
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The only time i can get some wheel spin is either in the wet, or around a corner.
And im only running 205 tyres.
I guess i am down on power/ torque, im only getting a 9sec 0-100. Its a series 2 Auto, should it be performing better?
Theres something wrong with my drive belt tensioner, its getting replaced tomorrow, i doubt it, since it doesnt power anything, but some of the power could be lost through it. |
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mouce
National Driver
1525 Posts
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Posted - 20 Sep 2006 : 8:13:06 PM
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I don't know about the auto, but I know the manual (driven properly) should be able to see 8 sec (I've heard of people doing 7s but never seen it myself).
I can't see why the drive belt tensioner would cause a drop in power, but anything is possible. It sounds to me that you're down on power/torque a bit. Might be worth looking into.
Then again, for the auto...you may be doing as well as possible. I know that no stock auto can chirp into second, might be worth looking at a shift kit. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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lolo
Fully Licenced
503 Posts
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Posted - 24 Sep 2006 : 11:27:30 PM
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| mate, forget tbs, u have a Series 2.., save your money and get a 4.2l stroker kit from COME Racing... that is guaranteed to free up some ponies |
Marcus Rogulic R.I.P (1980-2007)
"The Good Die Young" |
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mouce
National Driver
1525 Posts
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Posted - 24 Sep 2006 : 11:34:37 PM
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| Hell...just a straight port/polish of the heads gets a few extra out. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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lolo
Fully Licenced
503 Posts
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Posted - 24 Sep 2006 : 11:44:45 PM
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| hehe mouce... I knew u were around here somewhere |
Marcus Rogulic R.I.P (1980-2007)
"The Good Die Young" |
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