Jump to content

100 bhp / litre


nicksmelly

Recommended Posts

Personally I would be amazed,

The 2nd generation BMW M3 was notable in its day as the only naturally aspirated production car to have over 100BHP per litre. The V8 M5 only produced 400BHP out of 5 litres and the current V8 M3 produces more than 100BHP per litre.

As far as I was aware the normally aspirated but tuned Rover V8 was around 200-250BHP for a 3.5 unless very special, so I would not expect too much more from a 3.9.

HfH Nige would be good for comment on this I guess.

Marc.

Link to comment
Share on other sites

Since materials moved on to allow substantial turbocharging in petrol engines (above 1000degrees C EGT huh.gif) power levels have leapt up. 100bhp per litre would still be impressive from a naturally aspirated engine, there aren't many production N/A engines that beat that figure - though I'd like to check the calibration settings on the dyno sheets for the ebay V8...

Link to comment
Share on other sites

out of interest whilst at the autosport show the other week there was a rotrex tts performance supercharger stand that had a Honda type r engine stock hp 175 at the wheels that they uprated to 365 at the wheels.using twin Superchargers.

Is the type r 2 litre?

Just for £3750 + vat diy fitment, and a small note about highly recommending the use of uprated rods and pistons if being used for competition use.

Link to comment
Share on other sites

out of interest whilst at the autosport show the other week there was a rotrex tts performance supercharger stand that had a Honda type r engine stock hp 175 at the wheels that they uprated to 365 at the wheels.using twin Superchargers.

Is the type r 2 litre?

Just for £3750 + vat diy fitment, and a small note about highly recommending the use of uprated rods and pistons if being used for competition use.

Rob, it'll last about 2 minutes especially if it is a current generation Civic (which has weaker internals than the earlier version). That said, a K20a (first gen Civic type r engine) can be tuned to about 360 at the crank (so a little over 300 bhp at the wheels) with standard internals using a supercharger, charge cooler and some cams (TODA A3s are good but you'll loose some mid range). Something like this is likely to end up in my Lotus at some point :D

As others have said, 100 bhp/litre is still impressive in an n/a production car and, although easy enough to achieve on small 4 cylinders, it is impressive to get a figure like that out of a larger V8. It certainly isn't impossible BUT it's unlikely.

Link to comment
Share on other sites

As others have said, 100 bhp/litre is still impressive in an n/a production car and, although easy enough to achieve on small 4 cylinders, it is impressive to get a figure like that out of a larger V8. It certainly isn't impossible BUT it's unlikely.

so how do they get it out of smaller 4 cylinder 4 strokes - like bike engines - but cant do it with higher displacement engines?

Link to comment
Share on other sites

Exactly, a bike revs to 15k+!

The problem with getting 100hp/litre from an NA car engine is it needs to be very "cammy" to get there, which ruins emissions and makes it idle like a bag of spanners. The advent of variable valve timing means you can have aggressive enough cams to make the power, but at the same time have an engine that idles properly and passes the required emissions standards.

Audi and BMW are both getting more or less 100bhp/litre from large V8 motors, but the major issue with bigger engines is that more reciprocating mass means parts need to be made from lighter and more exotic materials so it doesnt self destruct doing 8000rpm. Audi and BMW are both also running modern multivalve heads with VVT etc.

The cylinder head on an RV8 simply cant flow those sort of figures, and the bottom end wouldnt stay in one piece!

Link to comment
Share on other sites

large cc usually means bigger pistons and that means more weight being forced to change direction very quickly, a piston goes from stop to full speed twice in one revolution cause at tdc and bdc the piston changes direction, years ago on my hnd engineering course we did simplified calculations on the forces required and the figures were frightening.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy