Any one running throttle bodies on an exocet

[beardy]

Some Miata based ITBs on UK forums. Many SDV (single donor vehicle) MX5 based Sevens, Locosts and MX-5s doing track days and circuit racing using everything from Jenveys to bike ITBs and standalone ECU. So look at MX5nutz, also try locostbuilders(dot co dot uk) and tech section of the westfield sportscar club forums, but come back HERE.
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Purely as a calibration point, contrast your old Miata BP lump with the recent Ford Yamaha designed 1.6 Zetec SE/ford Sigma. Shawspeed advertise 180 with cams and throttle bodies, and 200 with head work so I really doubt you can get to 300...

[davetherave]

Thanks for info so far

[welshy1]

Adding itbs on without any other work wont do a lot for power wise they need a lot of other supporting mods to get to 170ish bhp/ The standard engine is not that suited to n/a tuning as it came from the old 323f turbo rally car but without the turbo in the mx5 apart from the bbr models.
That makes the engine ideally suited to forced induction, supercharging is thought of as better in an exocet with a smother power delivery but for bigger gains turboing is better.
Im running a tdo4 set up which suits the exocet it has low down power boost comes in around 3k which is fine for track use and that's at 220bhp with a stock motor with plenty more to go.

A certain uk builder has managed 435bhp out of a 1.6 engine exocet but with a lot of money spent on the engine, he then went on to push it up to 3.1 bar of boost on racing fuel at he said 600bhp which then snapped the crank.

250-270bhp is about as much as the standard engine can take without risking bent rods which is the weak part with turboing.

[kiwicanfly]

Apart from looking cool what is the advantage of ITBs over a single TB of a size large enough to supply all the air the engine can use?

[beardy]

throttle response and glorious soundtrack

[davetherave]

Spoke to someone into mx5s and they said they wouldn't super charge they would go down the itb and head works but yo will pay a lot more money then supercharging but then again th noise of a charger is load on an Exocet

[kiwicanfly]

Sept 26, 2016 19:17:12 GMT beardy said:

throttle response and glorious soundtrack

Ok ignoring the noise........ well you can't

So what is it about the ITBs that improves the response and why do they reportedly tend to offer more power in general?

I am trying to compare the difference technically between ITBs and an adequate size single body, not a stock one.

[beardy]

I don't know enough about it, but I think that there are several things going on at once
1. much smaller total intake volume, means that when the butterflies are opened the intake volume fills very quickly versus a single body and typically larger plenum volume which takes longer to come to atmosphere.
2. very rapid change in opening as multiple butterflies are all opened together versus deliberately `softened' impact of typical OEM single throttle with linkage designed to reduce this rate of opening.
3. potential for better resonance tuning of multiple straight pipes of certain length versus different path lengths for each cylinder.
plus probably some other stuff which is more important that I have left out.