Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: vxer on July 11, 2006, 05:39:14 PM

Title: ratio relating AIT change to bhp change
Post by: vxer on July 11, 2006, 05:39:14 PM
Hi there,

Obviously as the AIT gets cooler, the ECU can add more fuel for more power in combustion. But does anyone know what kind of numbers we are talking about here?

e.g. is it 0.5 hp for every degree colder (on an FD, say)?

Cheers, Paul.
Title: ratio relating AIT change to bhp change
Post by: stuart wizy on July 11, 2006, 07:08:44 PM
1deg intake minus is 4 bhp gained, thats what I read anyway, thats why water injection is a big power gainer,
check scotts twin turbo quarter at 12.4sec using water and methonol, say no more!
Title: ratio relating AIT change to bhp change
Post by: maximtaylor on July 11, 2006, 07:35:45 PM
Roughly 3% or 4% gain per 10 degrees celsius temperature drop I reckon.
Title: ratio relating AIT change to bhp change
Post by: CraigN on July 11, 2006, 07:52:20 PM
Water Injection is a preventetive measure for someone who does not have a large enough intercooler.

The main reason for having water injection is to use it to lower combustion temps (IE Melting pistons or rotor tips) as standard most cars do this but with fuel instead of water.

It is not a replacement for a better intercooler. If you seriously want to use something other than a better intercooler nitrous is by far superior for cooling inlet charge.
Title: ratio relating AIT change to bhp change
Post by: maximtaylor on July 11, 2006, 08:03:02 PM
But far more expensive than water!

Quote from: CraigNIf you seriously want to use something other than a better intercooler nitrous is by far superior for cooling inlet charge.
Title: ratio relating AIT change to bhp change
Post by: vxer on July 11, 2006, 08:04:54 PM
Quote from: maximtaylorRoughly 3% or 4% gain per 10 degrees celsius temperature drop I reckon.

Ok, so i stand to gain about 14hp (if i had 255) by dropping AITs 20 degrees (which is probably the limit realisticly) ?

Cheers, Paul.
Title: ratio relating AIT change to bhp change
Post by: maximtaylor on July 11, 2006, 08:05:06 PM
Combined with a good intercooler the results are awesome. Below ambient intake temps are the norm.

Quote from: CraigNWater Injection is a preventetive measure for someone who does not have a large enough intercooler.