Hey guys,

Sorry if this has been discussed before. I am currently building my VIII with a 2.0LR and Stage 3 Head from BR w/ PTE 6466. Shooting for an 8 second car. I've seen people max out the Omni 4 Bar at roughly 7xx whp and wondering what would be better to get into the 800 club, the Omni 7 Bar or the AEM 5 Bar? I've heard the bigger the MAP sensor, the worse the response is, but am new to the tuning portion and wanted to see what people recommend. Thanks for any advice!

 

It depends how much boost you are planning on running. Every 1 bar = 14.7psi however I think the first bar is to account for normal atmospheric pressure. Now I'm not positive on this but I believe that is the case such that a 3 bar will only read up to 29.4psi 4 bar 44.1 so on and so forth.

Come to think of it I may actually need to upgrade my MAP sensor as I currently have the 3 bar. I'm in the process of retuning my BBK on e85 and slowly turning up the wick.

If my above statement is indeed correct which I think it is then I will need to acquire a 4 bar. In your case I think a 5 bar should be plenty but I'd wait for someone more knowledgeable to chime in.

 

I wouldn't jump to a 7 bar unless it's hitting boost levels that a 5 bar can't pick up, it doesn't react as fast due to the larger range.

 

What's the range on the 5 bar, 50+ psi?

 

Yes, with a 5 bar you should be fine up to 60 psi, no more.

 

What's 4 times 14.7?

 

So I take it what I thought regarding how high they read is correct in that the first bar is atmospheric pressure?

 

Yes the first BAR is dedicated to reading vacuum. Whatever is left reads boost.

 

Is there any truth to the OP statement regarding "bigger the MAP sensor, the worse the response is"?

 

If you have 2 sensors, one 5 BAR and one 3 BAR, and they are both 5 volt sensors then yes the resolution will be lower on the 5 BAR sensor. It's just math.

 

Thanks...that makes sense.

In this sense it's best to use the sensor that best fits the boost range you plan to run. Especially when it comes to data-logging.

 

Exactly

 

Thanks for all he help guys. I guess I'll have to switch my order out to the AEM 5 Bar!

 

You should get both, and show your log difs. Then we can all nerd out for the next two years discussing math.

I kid! Hope the 5er works out well! 800... Awesome.