New update 2/2..enlarged TB.

[litchy]

Just bought a 172 TB with plans to mod it. Heard mixed responses but why not. Just message a guy on fleebay who will machine out the throttle body to a larger bore, fit a new butterfly thats been CNC machined to the precise angle to ensure a snug fit, using 2mm ground aluminium plate with the spindle modified to suit. The throttle bodies will be re-greased and polished to a mirror finish.

Might be a waste of time but worth a try. Anyone else modd'ed their TB?

 

[Graeme GTR]

heard of people having the lip machined out of them but nobody i dont think has ever seen a proven gain. Cant do any harm though can it?

 

[Richy200]

having the inside of the throttle body polished is meant to decrease performance and it slows down/stops the venturi affect on the air. So I've heard.....

Be interesting to see if you feel anything once done

 

[ryan197]

venturi effect is a load crap tbf, its volume of air not speed of air that needed, and the inside surface of the throttle body is due to the manufacturing process tomake a smooth surface for the butterfly.

 

[ryan197]

how much was it to get the body done litchy? pm me if you like

 

[Robo_#1]

It's an interesting idea mate, you getting some.before/after rr readouts? It's worth a shot if nothing else.

 

[litchy]

how much was it to get the body done litchy? pm me if you like

It's an interesting idea mate, you getting some.before/after rr readouts? It's worth a shot if nothing else.

Its 55 quid, not had it done yet but should be sorted in a couple of weeks. Could be another one of those things like the v6 airbox and matched inlets that create so much debate.

I guess time will tell.....

 

[ryan197]

could you get it cheaper if there were two bodies? ive got a spare one in me garage?

 

[litchy]

could you get it cheaper if there were two bodies? ive got a spare one in me garage?

Could ask the question but think its cheap to be honest.....

 

[Foxspeed]

having the inside of the throttle body polished is meant to decrease performance and it slows down/stops the venturi affect on the air. So I've heard.....

Be interesting to see if you feel anything once done

it will be interesting to see what the effect is......

hurry up and get it done :shout:

 

[ben_r1]

I machined out the lip of my TB myself with the dremel and some wet & dry. Wasnt too difficult a job to be honest, just took a long long time!

Slight mid range response improvement but no negative effects.

 

[ryan197]

what about the inlet to the plenum, would this also need machine out to match?

 

[fmp]

Some interesting info here for those swapping parts out becuase bigger = better....

The size of throttle body effects engine response and peak hp. Here are some simple rules.

Large cross-sectional area increases throttle response.
Large cross-sectional area increased high rpm torque.
Small cross-sectional area decreased throttle response.
Large cross-sectional area increased low rpm torque.

Note: that “required” cross-sectional area is dependant on HP.

The following equation is a good rule of thumb for throttle body diameter (~ +/- 5%)

D (“) = sqrt[(WHP x 4)/(AP x CR)]

sqrt = square root

D = diameter of throttle body (single)
WHP = wheel horse power
AP = Atmospheric Pressure (14psi)
CR = Engine compression ratio

Cross Sectional Area = 3.14 x (D/2)

 

[Raptor6767]

^^so, basically, you're saying that if I machine out that lip i would get better throttle response/rpm torque?

So, why would they in the Renault make the throttle with that lip if making one without is less pain in the arse/cheaper?

 

[litchy]

^^so, basically, you're saying that if I machine out that lip i would get better throttle response/rpm torque?

So, why would they in the Renault make the throttle with that lip if making one without is less pain in the arse/cheaper?

Im planning to enlarge the TB and also polish and remove the lip. One thing I've noticed is that with the clio, the small stuff sometimes gets the best results. I think its a mod that combined with others that will make a small change. But thats one of the things I like about moddin it. As you know from your own experience, some of your best mods were the cheapest.

With regard to Renault, its obvious that they have cut corners. The cast of inlets are an example of this. I'm guessing the lip was there from how they are produced rather than any other issue.....

 

[Raptor6767]

http://www.clio197.net/forum/showthread.php?t=12803&highlight=throttle+body

http://www.clio197.net/forum/showthread.php?t=1550&highlight=throttle+body

I'm still sceptical untill I see the dyno results (it would be best to do the dyno on the same day because there will be no big difference so the weather conditions can influence the result if going on the dyno couple days later - IMHO).

I would love to believe that something can be gained from this cheap mod...but...we shall see...

 

[Klinck]

I ported/matched my inlets along with boring out the throttle body last month and my car feels like it has better response

Also tempted to get a sprintbooster so i can open the throttle when i want it to and not what the ECU thinks

 

[NICKHYND]

Sprintboosters well worth a punt mate...gives great response !!

 

[Benmc]

What are these sprint boosters??

 

[NICKHYND]

plugs into between the electrics on accelerator pedal and makes the fuel signal 100% instead of 70% as standard...really kicks off from standing start with out hesitation !!! gives 3 settings, normal,quick,and rapid