[Lowspeed Lowside]

Originally Posted by CThunder-blue

I unsubscribed from this thread a while back, but I wanted to correct you on 1 point.

I think I need to correct you on several points....

The exhaust gas after a turbo is far hotter than a naturally aspirated engine will put out. I'm not sure where you got that info,

If you read carefully, you'll notice that it wasn't about comparing a 'naturally aspirated engine' to a turbo! The diameter of the exhaust pipe is larger after the turbine, so according to PV=NkT the exhaust will be cooler. Here is a another way of looking at it: temperature is the average kinetic energy of the individual gas molecules and since the molecules 'hit' the turbine blades to spin the turbine wheel the molecules will slow down.

but it's typical to see 800+ F exhaust from turbo engines during max load. A heated sensor is just fine though since it will help during cold starts.

I don't know where you get your info from...turbocharged 250cc are not typical, so any 'typical' values for 500000cc diesel engines running 800psi boost are not really helpful.

Also, we want our lambda sensor to work at most loads not just at maximum. Which reminds me that we need to add a variable resistor to measure throttle position. Riding the bike through extreme conditions might require 'recalibration' by occasionally opening and closing the throttle all the way.

We might as well save $10 and use only one unheated sensor or possibly none at all. The fuel injection setup should be able to figure out air/fuel mixture by constantly varying the mixture by say 1% and checking how much the engine speeds up or slows down.

Also, venom injectors are complete junk. It's why they're priced lower than competition.

I don't think you understand the concept of a budget. Simply stating that something is 'complete junk' without providing an alternative is not helpful, and although I'm sorry to hear that you unsubscribed from this thread it's probably better you don't post anything.

To all others (if there are any left ) we have 4 intake valves so we might consider aiming 4 injectors at them. For an extra $40 we get a little bit of redundancy, so if one injector fails the computer can disable it and use the other one. We're also better prepared should we want to run pure ethanol (when gas hits $100/gal), which requires larger quantities of fuel.

Fuel pumps are measured in LPH or GPH, not psi.

So? The problem is that LPH or GPH is irrelevant as long as the pump can can provide enough fuel. But, using a 100Gal/min pump generating 14psi and running 14 psi boost will result in zero fuel flow. This is obvious to me, I fail to see why you don't understand why the pressure of the fuel pump matters.

Blow off valve for $20? Sorry, but that won't likely protect your engine or turbo even once. Quality BOV's go for $200+.

Really?

"my shadows mitsu turbo is fine and it has 125k on it without a BOV."


The purpose of the BOV is to protect turbine wheel when the throttle is closed quickly. So with appropriate throttle control a BOV would never trigger. We also don't need a device that prevents us from shifting into 1st gear and popping the clutch at 90mph.

So, I think we just saved $20. Also, trying to protect a $200 turbo with a $200 BOV seems a little extreme, don't you think? We can always add one later.

You also left off needing custom flanges made for the turbo.

True! But what do you think we need to spend on a piece of metal with holes - $400? Did you read somewhere that titanium with a signature by Leonardo DaVinci is much better than steel so we should be using that?

Also, did you plan on running wastegate pressure or using a boost controller? A decent manual boost controller from Joe P will set you back $45 too.

I was thinking of using the built-in wastegate control of the RHF3 turbo, since it's built-in. The advantage of built-in things are that they are built-in so that it's really unnecessary to worry about extra stuff that is not built-in, as not built-in stuff is extra. Not to mention that not built-in stuff is extra, and since it is extra it will likely cost extra money. Money is the stuff we use to buy things and there is a limited supply of it.