Ram air?

For general chat, questions etc about cars designed by JP - the main forum
Toed64
Posts: 32
Joined: Thu Jun 30, 2016 12:39 am
Name: Alister Monro

Ram air?

Postby Toed64 » Mon Feb 12, 2018 10:26 am

Hello all

I have a Sylva Riot with formerly carbed R1 engine. It's fitted with GSXR 750 throttle bodies with a DTA ecu.

When I bought it, it was running very poorly, variable torque and low output and was ear-bleedingly noisy. We removed the foam air filter and fitted a GSXR air box/filter and added another silencer across the back panel.

The chap that mapped it was not keen to blow it up, so he only revved it to 11000rpm - whereas the original red line would have been 11750 (I believe). It produced 135bhp at 11000rpm: about 40bhp more than it was limping to when I bought it.

I was looking at a GSXR 750 the other day. It had a ram air system, which got me thinking. I have lots of cool air swirling around the engine from a big Subaru STi scoop on the engine cover, but no piped and sealed cold air intake. Fixing some air ducts on would be quite straightforward, but I'm not sure where to mount the intake mouths...and not sure how much difference it might make.

I'd be grateful for your thoughts?

jeffw
Posts: 2605
Joined: Wed Jul 01, 2009 12:31 pm
Name: Jeff Wiltshire

Re: Ram air?

Postby jeffw » Mon Feb 12, 2018 10:28 am

All of these bike engines where designed/mapped to use sealed airboxes with ram-air intakes.

User avatar
peter030371
Posts: 447
Joined: Wed Jul 01, 2009 1:37 pm
Name: Peter Smith
Location: Hawkhurst

Re: Ram air?

Postby peter030371 » Mon Feb 12, 2018 10:36 am

RAM air only works at high speed (high speed being 120-130+) and even then you will need your ECU to be running a manifold air pressure sensor to use the 'extra air' and the gains are very small. However a good clean (not to much disturbance) and cold air feed makes a difference at almost any speed.

If this air feed happens to give you some RAM effect for free then go for it but unless your current air feed is warm and turbulent then don't expect to really notice the difference.

You have probably made the biggest gain by fitting the GSXR airbox back on as they spend a lot of time tuning the intake system for maximum gains.
Editor of 'The Proper Job'

Toed64
Posts: 32
Joined: Thu Jun 30, 2016 12:39 am
Name: Alister Monro

Re: Ram air?

Postby Toed64 » Mon Feb 12, 2018 11:51 am

The air box has made an enormous difference to the performance - I can now use the loud pedal a lot without getting a splitting headache!

The air flow around the engine is very turbulent and, of course, it gets very hot under the engine cover when not moving, but cools quickly when under way. I think some fresh air would make a difference, but I think to get any ram effect, the scoops would have to be huge and on the side panels because the draft over the cockpit and engine cover is not consistent.

The gearing on my Riot won't allow for 120mph+! The last owner just geared it down to allow the possibility of pulling away from a standstill (well, 3 time in 5!). Now it's mapped properly and there's enough juice to the pumps, it's much more driveable.

I'll start looking for something that might work.

Thanks for your advice.


Return to “Jeremy Philips Cars”

Who is online

Users browsing this forum: No registered users and 13 guests