R400 Duratec - drive by wire throttle?

[RobM77]

EVO complained of poor throttle response in the Duratec R400 they test in this month's issue. Does anyone know if the car is fitted with a drive by wire throttle? I just wondered, as I've never heard this complaint of any 7 before. The other possibility is that the throttle response is just poor when compared to those lovely roller barrels on the old K series R400.

[mikee]

Drive by wire on a Caterham, no way!

I think it might be a function of using a plenum instead of direct to head throttle bodies or roller barrels. I was told by my engine builder that the plenum has many benefits, doesn't compromise power too much but can have a tendancy to have a flat spot just above tick over. Maybe that's what they refer to?

Friend of mine is picking up his new R400 next week so I'll get the opportunity to do a back to back comparison with my R400 Duratec on throttle bodies.

[scalper]

don't know about the R400, but doesn't the new 115bhp Sigma for the export markets have drive by wire throttle?

[RobM77]

mikee said:

Drive by wire on a Caterham, no way!

I think it might be a function of using a plenum instead of direct to head throttle bodies or roller barrels. I was told by my engine builder that the plenum has many benefits, doesn't compromise power too much but can have a tendancy to have a flat spot just above tick over. Maybe that's what they refer to?

Friend of mine is picking up his new R400 next week so I'll get the opportunity to do a back to back comparison with my R400 Duratec on throttle bodies.

phew! Could you post back here about your experiences of the two cars please?

[mikee]

Will do once I've persuaded him to let me have a go on track, he drove my R400 at bedford last year when he had an R300 - his words were jeez it has sooo much power

Edited by mikee on Monday 7th May 21:06

[tvrted]

the one standing my garage has a cable operated throttle, but this is no use as I don't have the cooloing system from CC.

[RobM77]

The reason that this concerned me is that more and more manufacturers are putting drive by wire throttles on their cars with a time delay between pressing the throttle and the engine responding. This may sound madness when put like that, but you'd be amazed at the number of people that don't notice. The 350Z does it for instance, and this forum is full of people raving about them. Top Gear love it, as do EVO magazine. I've never seen the throttle delay mentioned anywhere, but for me this aspect of the car renders it totally undriveable as I can't balance it in corners and everyday driving is frustrating and annoying. All BMWs do it as well (other than the diesels for some weird reason). I paid £16k for a 330 coupe from BMW two years ago. It had a whole second's delay - it was long enough to measure on a stopwatch. I rung BMW up the next day to ask for my money back and they offered me £12k! I ended up trading it in for £10k after three months of tryin to sell it privately in exchange for my current car, a Lotus Elise 111S with a cable throttle! You can read all about this on this very forum if you look back to Spring two years ago.

[dannylt]

There is no reason a drive by wire throttle should cause more delay than a cable except because of it's programming. And the delay is programmed in for emissions - for the sharpest response you just want to dump a load of fuel.

[1st_petrolhead]

RobM77 said:

EVO complained of poor throttle response in the Duratec R400 they test in this month's issue. Does anyone know if the car is fitted with a drive by wire throttle? I just wondered, as I've never heard this complaint of any 7 before. The other possibility is that the throttle response is just poor when compared to those lovely roller barrels on the old K series R400.

I would hazzard a guess and say it was probably down to poor mapping