Duratec / Gearbox

Wes I spoke to Steve and he is progressing with the Duratec kit. He wants to make sure it is 100% perfect before he lets one go.(sounds like its going to be a very good conversion.

Yep, I was referring to Steve Williams - hadn’t spotted Sean’s post until today

Russ’s Honda rotrex car is well over 400BHP and he didn’t have any engine problems last year.

How did he get to that? Is that just the supercharger on a standard engine, or has he swapped out a load of internal parts also?

David

Honda n/a won’t be faster than a VHPD in a straightline, but it will be quicker around the track, plus IMO much more pleasurable to drive in all circumstances.

It is slightly quicker as I found spending a 20min track session on the tail of Mr Scuffham at Snetterton a few years ago when mine was still VHPD powered.

It is slightly quicker as I found spending a 20min track session on the tail of Mr Scuffham at Snetterton a few years ago when mine was still VHPD powered.

Fair enough, suits me sir!

As a matter of interest, Mark, any idea what sort of speed you were reaching at Snett? I’ve never been close to “maxing” mine anywhere, although I’ve had a reading of 145mph, in France.

I would have thought that 30 or 40 hp more would have been more than slightly quicker. Am I missing something here?

David

Standard Honda in Civic is 197bhp. I’ve never had mine fully mapped on a rolling road, so I’m guessing it’s somewhere between 200 & 210bhp (it has better induction/silencer than the Civic, but exhaust manifold is far from ideal*). The real advantage on road & track shows in midrange performance, where the torque curve comes into play. I would imagine you experienced that yourself whilst driving the Bat Erise?

You need quite a long straight for the extra grunt of the Honda n/a over the VHPD, to become apparant, as far as top speed goes. With the s/c Honda the bhp is usually 280 to 300, so there is a substantial gain in that respect.

  • Part of present ongoing upgrade work includes proper exhaust manifold.

I would have thought that 30 or 40 hp more would have been more than slightly quicker. Am I missing something here?

I’m guessing on power as Simons Elise would have been around 225bhp and my VHPD, who knows, I never had it tested, but assuming it was 190bhp (as it was never a ‘slow’ vhpd).

He probably pulled out about 3-4 car lengths by the end of the straight and then I took it all back through the bends. He was having issues with crap wet weather race tyres IIRC. (at least that was the excuse )

It’s was due to the length of the Snet straights that it was really making a difference, around somewhere like Brands the difference is much less. I once had a good few laps with Steve Williams who was in a Honda’d 340R when I had the vhpd and he was only just a touch quicker over a lap, there was almost nothing in it.

But of course in both cases this is in a trackday so not 100% on it.


Rob,

No idea, I don’t tend to look at the speedo and remember speeds, only time I’ve ever done so was at Rockingham as I started to realise how close to the limit I was getting through the 1st chicane (over 100mph )

But of course in both cases this is in a trackday so not 100% on it.

You & Steve? Pull the other one

But of course in both cases this is in a trackday so not 100% on it.

You & Steve? Pull the other one

Well said Pesky - this is the man who was sideways in his Nissan Navara at Bedford ! and no it wasn’t on the sighting laps

[I don’t tend to look at the speedo and remember speeds, only time I’ve ever done so was at Rockingham as I started to realise how close to the limit I was getting through the 1st chicane (over 100mph )

That’s a very impressive speed through there…but not as impressive as having time to look down at the speedo

I think that’s one of the hardest corners on any circuit, always feels like trying to thread the eye of a needle.

David

Standard Honda in Civic is 197bhp. I’ve never had mine fully mapped on a rolling road, so I’m guessing it’s somewhere between 200 & 210bhp (it has better induction/silencer than the Civic, but exhaust manifold is far from ideal*). The real advantage on road & track shows in midrange performance, where the torque curve comes into play. I would imagine you experienced that yourself whilst driving the Bat Erise?

You need quite a long straight for the extra grunt of the Honda n/a over the VHPD, to become apparant, as far as top speed goes. With the s/c Honda the bhp is usually 280 to 300, so there is a substantial gain in that respect.

  • Part of present ongoing upgrade work includes proper exhaust manifold.

Yep, I noticed three things whilst driving the Bat car -

  1. The engine is a lot smoother and the gear change is far better
  2. There was more mid range
  3. I wanted one badly :O)

I would have thought that 30 or 40 hp more would have been more than slightly quicker. Am I missing something here?

I’m guessing on power as Simons Elise would have been around 225bhp and my VHPD, who knows, I never had it tested, but assuming it was 190bhp (as it was never a ‘slow’ vhpd).

He probably pulled out about 3-4 car lengths by the end of the straight and then I took it all back through the bends. He was having issues with crap wet weather race tyres IIRC. (at least that was the excuse )

It’s was due to the length of the Snet straights that it was really making a difference, around somewhere like Brands the difference is much less. I once had a good few laps with Steve Williams who was in a Honda’d 340R when I had the vhpd and he was only just a touch quicker over a lap, there was almost nothing in it.

But of course in both cases this is in a trackday so not 100% on it.


Rob,

No idea, I don’t tend to look at the speedo and remember speeds, only time I’ve ever done so was at Rockingham as I started to realise how close to the limit I was getting through the 1st chicane (over 100mph )

Hi Mark, thanks for the info. You must be a bloody good driver to stay with a Honda’d 340R with a VHPD in the back !!!

Can I ask what engine you are running now, are you still with the VHPD ?

Yep, I noticed three things whilst driving the Bat car -

  1. The engine is a lot smoother and the gear change is far better
  2. There was more mid range
  3. I wanted one badly :O)

Quite a few of us would agree there!

You should also try the Audi, before deciding which is the most suited to you

Who has the Honda Rotrex?

Any more details, pictures etc etc…

Who has the Honda Rotrex?

Any more details, pictures etc etc…

RussT

Plenty of pics (Dayglo Orange Exige) here, although you’ll have search for engine bay shots tsuphoto.com - tsuphoto Resources and Information.

Here’s one that might be helpful…

Though I�m sure there�s another one in there with the engine looking all shiny and new .

David

Here’s one that might be helpful…

Oi you, you’ve not got time to go sorting through thousands of pics - get yer bloody homework done!

Mate, I�ve just done 2 weeks of Exams, so, to be honest, I�m finding it kinda tricky to be arsed right now .

David

PS. Just for the record, this is the one I was on about: tsuphoto.com - tsuphoto Resources and Information.

Is the rotrex more like a belt driven turbo? So making it a compressor rather than a pump?