Larger Throttle Body

[Get EPIC]

Hi all,i am about to get a forward facing plenum installed on my R33.It has an adapter plate to fit the standard throttle body but i am considering going a 80mm TB.Would this have any gains with a stock series 2 turbo or only when putting a larger turbo on?

[Dorifta]

bigger pipe=less response, and more flow at top end, not woth it unless u have a big turbo

[R31Nismoid]

There is no gain upgrading the T/B.

The only thing you get is less throttle control, i do not rate that as a gain.

Few people around here have actually put the factory one back on because larger TB's are too "on/off" in low throttle applications.

Ok if you are drag racing, but daily driving etc, no no.

[PM-R33]

Bit of a controversial subject on turbo cars, every one has a different opinion, not many people do back to back tests. I posted up the atricle from Autosalon a while back, ill try and find it.

Here it is in Nick's thread. Half way down. http://www.skylinesaustralia.com/forums/Mo...html&st=180

I'm going to change mine over to the plazmaman one when i get around to it one day to match the plenum.

[aDrew_C]

Only go for a bigger tb if you're seeking peak hp and don't care about driveablity. I'm staying standard...

[r33cruiser]

bump.

Has anyone run into problems wiht the stock t/b with higher hp?

Will a stock t/b handle 500hp+? Has it been done?

[R31Nismoid]

I made 370rwkw, Guilt-Toy has also.

[r33cruiser]

thankyou kindly. was waiting for u to post.

[Ryno]

I run an 80mm throttle body and really like it as far as drivability goes. You probably don't quite have the same control at low throttle, but I wouldn't say it is on or off. It only took me a drive or two and it felt as natural as when driving with the stock one.

What is cool, is that you will find it easier to blip the throttle when down shifting, as you don't need to stab as much of the throttle (with your heel) when compared to stock, to get the revs up.

As for performance, there is probably very little gain, but I don't regret the purchase and wouldn't go back to the stock one.

[r33cruiser]

Cool. I just didnt want to re-bore my plenum (still stock sized opening) as i cant with the position that the hole is in.

^^ I hope you bored your's out to 80mm. Seen ppl claim to gain hp with 100mm t/b's but still have the stock 65mm opening in the intake plenum LOLZ

[TiTAN]

if he has the Greddy plenum they come factory with an 80mm hole.

[Ryno]

No I didn't have to worry about that, as I've got an aftermarket plenum. (See attached Pic)

[NYTSKY]

bump.

Has anyone run into problems wiht the stock t/b with higher hp?

Will a stock t/b handle 500hp+? Has it been done?

530rwhp

[T04GTR]

the only gain is if the plenum has a shit distribution. but you loose low speed response. if you do get a gain its because the plenum is not great.

if you have a look at alot of the older turbo race cars all have no bigger than 75mm. (same size as the pipework.)

1400hp 4cyl with a smaller than 3" tb says alot.

just dont put one thats bigger than the plumbing. complete waste of time.

75mm is big as youl ever need. ever.

[WARLORD]

ive got one love it,

i have no problem with control,

if you going the hole hog on a set up than do it,

thats my opinion.

most gtrs that go singal t/b use a 90mm,if there was no diference why do the use them an not a 75mm one ??

Edited February 7, 2010 by WARLORD

[R31Nismoid]

Because someone told them they needed to, and they believed it.

I've seen GTR's make 450rwkw, factory plenum/intake, so there is hardly a reason for it.

[TiTAN]

There is the ease of tuning with a map based ECU when its single TB instead of multiple, which may have had something to do with it also.

I like my Q45 TB, yes it is a little different to drive with than the stock TB as you don't have to be on the throttle that much to get it moving but it hasn't made the car annoying to drive around town. Investing in a clutch that doesn't require super human leg muscles to operate will go further towards making it nice to drive everyday than a smaller TB.

Edited February 7, 2010 by TiTAN

[T04GTR]

ive got one love it,

i have no problem with control,

if you going the hole hog on a set up than do it,

thats my opinion.

most gtrs that go singal t/b use a 90mm,if there was no diference why do the use them an not a 75mm one ??

because having a larger one slows the air velocity down stopping the last couple of cylinders getting more air that the front few, giving a more evan distribution.

like i said. if the plenum is not a great design then gains will be had. but at the cost of low load drivability. not a big loss but a loss.

put a flamin mongrel clutch in and it will show its head very fast.

the same reason its good to put a centre fuel feed in a fuel rail once your got a really big fuel pump,it slows the fuel flow down in the rail so each injector has time to grab the same amount of fuel along the length of the rail...

there will be no gain installing a larger throttle body than the piping.

oh and that on a gtr the plenum is already 80mm to begin with...

[WARLORD]

and a greddy plenum would be bigger again,

that's what i meant by the hole hog,hopefully soon when my dam exhaust manifold is finished i can show that having all not some of supporting mods from A-Z all together makes for a good package.

well that's the idea

as for a o/s t/b on a stock plenum and stock turbo and so on,yes its a waste of time.