50mm SE throttle body is one piece & comes with the 4.89 injectors, flanges & seals, IAC & all the other sensors. For the price, it's pretty good value & will work well with your combination. Although the HPI 51mm or 55mm pieces are better & dearer, they only come supplied with the flanges. - Rob

Ozymax.

I run a 107 11.2 to 1 compression 2" inlet and 1.625 exhaust ported heads from Tman and his 662-1 cams, and i am running a HPI 55mm throttle body and manifoild with SE 4.9 injectors goes like a cut snake, no throttle lag at low speeds and runs hard when the cams kick in. 

Thanks guys
for what ever reason I didn't even think about this area until today. I got a few weeks before every thing arrives but I would like to sort this area before it all gets here.

I was thinking 55 but really need to know more about my port size first I think. Then need to peace it all together.

Guess I can blend the 50 SE to the ports and wouldn't loos anything over what I have now thats for sure.

Wouldn,t the throttle body have a cfm rating for each size as to how much it can flow . Then , with the cubic capacity of your motor and the max revs it will go then be a calculated cfm figure ? Just thiking out loud .

stock one will work but will be leaving some behind.
I dont have the info on the heads, still waiting for it

I am looking for all torque with good response and the HP will be what ever it is so the SE 50 with 4.3 I think will be ok. 58 may be to much I think.
can always swap the 50 out down the track if need be.

your correct as usual 4.9
Yea I'll blue it when the heads arrive and blend it to match, clean every thing up a bit also

450 complete delivered which I thought wasn't to bad considering local mob was 535

Hey Ozy,

Sound like a good build.

I've got the 58mm with 4.9 injectors, Tuned right it has perfect manners.

Really grunty down low and heaps of top end and sharp and instant throttle response. 

Don't know why the 58mm TB get bad press. Just not tuned right I guess..

I'm no expert but been around car injection a bit.

Haven't really seen any proof that a TB can be too big within reason but have seen properly tuned larger TB's make more torque and HP right thru the rev range.

What to others think?

Stock 46mm and SE58mm

 

Carburetors are a bit different to EFI, they need good velocity and vacuum to idle and draw the fuel thru the jet and venturi.

Had a mild 350 small block with a Rochester 730cfm I think , that ran awsome. Tried a few Hollies, rubbish.

Fitted a 4 barrel 1000cfm TB on the same manifold and tuned it, more everywhere and better thottle responce and 4 tenths  quicker.

Now on the same set up you would not fit bigger than 650cfm Holley.

For interest look at the Dyno graphs in the SE catalog. 103 st4  and 110 pro kit.

Both have 10.5-1 comp, both have 259e cams. 103 kit has 58mm TB and 110 kit runs the stock 46mm.

The 103 kit  has better torque and HP.

I would like to now if any one has  run a built motor with say a 51 or 54mm TB tuned and dynoed.

Then change to a 58mm TB and see if it gains or loses. That would be interesting.

 

Yes very true Hilly.

Dyno WOT numbers are only 5% of your usable rev range if that.

There's a whole other world under WOT.

Most riding is done at around 5 to 20% throttle.

But you would think that if a large TB is making good numbers at 2500 to 3000rpm at WOT it should also be good at part throttle openings.

What do you think?

Dyno graphs should show HP and TQ numbers at 5, 20, 50 and 100% throttle openings that would give a lot better info on which parts work best together for a given set up.

 

Am just about to change from a 55mm to 62mm,5.3gps to 6.2gps injectors. Be interesting to see how it rides and if the current 135hp/130ftlbs suffers.Lol

Pan is on the water mate