Hasselgren 4age billet barrel throttle

[PRIMRK]

http://www.youtube.com/watch?v=1aFd4LtS9LA

While looking for some ideas of what to use for throttles on the 3UZ-FE I came across the 'roller' type throttle body, i had never heard or seen these before so i thought id chuck them on here for every one to have a look at it.

More info and pics here:
http://hasselgren.com/category/racing-engines/toyota/

[plohl]

splooge!

[hachirusto]

very cool but I don't think they would be as responsive as a normal butterfly more mass to move when opening

[n2866]

they are the oppisite of what you think actually alot rougher and produce more power..when driving they are closed or a bit open hard to explain but ive heard you would struggle to drive on the roads

[lolwat]

only good if your either off it or flat chat gasing it

[PRIMRK]

but unlike slide throttles the application is still linear

[ke_70]

i would say they would have much better air flow as there not a butterfly in the middle disrupting and restricting air flow (air velosity?).

these would have a much more smoother and prisice power delivery.

these are just my own observations. so i could be completly wrong?

[n2866]

yes you are right about the first wrong about the second.

[plohl]

^^ mostly at WOT though - intermediate throttle positions would still have loses similar to a butterfly valve.

And I don't think the actuation would be linear unless you were running a well thought out cam in the linkage. Area would increase a large amount during low to medium throttle positions and level out toward WOT. One of the reasons why they're not really suited for road cars.

[Twinky]

Who races down a straight at half throttle anyway? I could see how this wouldn't be too good for trailing throttle though, but I wouldn't say that it would be all that bad.

[PRIMRK]

But due to the square shape of them it allows a linear air flow as it opens, i don't really know what people are saying it will have losses in the intermediate positions, the point of a throttle body is to control airflow so by nature its there to restrict air flow, its at WOT that the advantages are seen. if you are after a circular or elliptical roller type it will use twin rollers to get a linear feeling throttle.

Am i correct in saying this?

Advantages of the roller type is like the slide, at WOT there is no restrictions, but unlike the slide the throttle control is linear, and therefor driveability is improved.

[plohl]

^touche - didnt even think about the intake shape influence. You would think the slider with rectangular intakes would produce a linear increase also?

[PRIMRK]

I would have to say yes though I haven't seen them befor...with a circular slide the air flow is a bell curve due to the width of the circle changing as the slide opens, so if it was a square I don't see why it wouldn't be linear.

Or am I missing something?

[plohl]

Nah, thats the same reasoning i have

[Vance]

isnt the hasselgren 4age turbo'd anyway? with boost this wouldnt have much issues with partial throttle unlike NA

[Gunner]

Have any of you guys seen the underside of roller throttles? its not the same as what you see from the top.

[PRIMRK]

check the link it seems to be the same front and back in those pics...

[Gunner]

hmmm true, but is it? I played around with a rather serious GTR a few years back, and the underside of the throttle plate (for lack of a better word) was scalloped, supposedly to allow even air flow along the face of the port, I was still an apprentice at the time, but thats what the bossman told me.

[plohl]

pics???

[PRIMRK]

yeh if you can find some pics similar or draw something cos im curious what exactly you mean by that...

[Gunner]

Nah no pics of that car in particular, as I said it was a few years back, but I'll see what I can find.