How much boost on the EVOIII on 2g with 100 octane

[Mike_GSX]

Hi,
I'm wondering, how much boost I can go with with my EVOIII (haven't received it yet)
Mods will be: EVOIII inlet & outlet ported, portet, ported manifold, ported O2,550cc or 650cc, 255 fuel pump, SBR 2g FMIC,...

I'm just curious, what is normal gas and what is race gas?

Here in Europe we have Shell V Power (100 octane). Thats the gas/fuel I always use.
What do you think, how much boost would be good with this gas on a EVOIII ?

thanks

Mike

 

[CanadianTSi]

Should be able to do 25psi with the proper supporting mods.

 

[2gGSX]

Make a few logs and while keeping the AFR steady keep upping boost until you either can't anymore or get knock.

 

[andymoraitis]

Mike,

How much boost you can run is mostly dependent upon your state of tune. In light of this, we need to know what you'll be tuning with. Are you running an AFC, DSM Link, EPROM ECU? That alone will affect how much boost you'll be able to run (especially the AFC since it will skew the timing maps based on airflow). If you haven't made up your mind, please drop me a line and we can discuss it further.

Based on 100 octane fuel and a solid 11.5-11.7:1 AFR and 19-20 degrees of timing, you should be able to hit 24-25 psi on the EVO III. Having a way to monitor knock will be critical as you can find the edge of your tuning limit and then back the boost down safely to apoint where there's minimal knock.

Also, if you stick with the 255 pump, you'll need an AFPR to set the fuel pressure to 43 with the vacuum line disconnected. The 255 is known for serious overrun of the stock fuel pressure regulator and the resulting rich condition will kill your air/fuel ratio and ruin any chances you have for peak performance. The EVO III does not require a 255 and if I were you, I would purchase a 190 instead and remove the AFPR from the tuning equation. In the long run simple things are more effective. Also, the 650's would be a better choice since they'll run a lower duty cycle and last longer than the 550's.

Hope that helps,

Andy