Tech Inspection L15B7

[dc2turbo]

Didn't see this get posted

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[NorthernEX-T]

Where the CRV turbos at?!

 

[16civicFLA]

Where the CRV turbos at?!

I got a quote from my boy that works at Honda I can get it for $660 but I'm waiting for vit to let us know about the one that he is developing...

 

[ACG12]

Where the CRV turbos at?!

What's the difference?

 

[rwmurrayvt]

What's the difference?

I'm extremely interested in this. I can't find any technical details anywhere online. If the the only engine upgrade on the SI is the CR-V turbo, I imagine it'll fit just nicely on my sport hatchback.

 

[NorthernEX-T]

What's the difference?

I'm extremely interested in this. I can't find any technical details anywhere online. If the the only engine upgrade on the SI is the CR-V turbo, I imagine it'll fit just nicely on my sport hatchback.

Watch the friggin video guys!!!

 

[rwmurrayvt]

Direct link to when he discuss the differences ~8:00 into the video.

11 fins on EX vs. 9 fins on SI exhaust wheel on the turbo. This allows the turbo to make more HP at higher RPM. The back pressure limits how much HP it can produce at higher RPM.

Cam shaft. The lobe that drives the fuel pump on the SI model is taller in order to boost fuel pressure. It may be necessary to overcome increase in boost pressure.

Possible third difference (?). The dual mass fly wheel on the EX is there as a comfort measure. The guy in the video expects a single mass fly wheel in the SI.

Edit: So that covers how they go from 180 to 190 for the CRV. I'd assume they have a finer/sportier tune on the ECU for the SI compared to the CRV. The biggest question for me now will be how much room for improvement with a simple tuner will be left.

 

[NorthernEX-T]

Direct link to when he discuss the differences ~8:00 into the video.

11 fins on EX vs. 9 fins on SI exhaust wheel on the turbo. This allows the turbo to make more HP at higher RPM. The back pressure limits how much HP it can produce at higher RPM.

Cam shaft. The lobe that drives the fuel pump on the SI model is taller in order to boost fuel pressure. It may be necessary to overcome increase in boost pressure.

Possible third difference (?). The dual mass fly wheel on the EX is there as a comfort measure. The guy in the video expects a single mass fly wheel in the SI.

Edit: So that covers how they go from 180 to 190 for the CRV. I'd assume they have a finer/sportier tune on the ECU for the SI compared to the CRV. The biggest question for me now will be how much room for improvement with a simple tuner will be left.

Way too nice you are SIR!

 

[VitViper]

Cam shaft. The lobe that drives the fuel pump on the SI model is taller in order to boost fuel pressure. It may be necessary to overcome increase in boost pressure.

The system runs 2600psi of fuel pressure from the factory. Trust me, your boost level is irrelevant with the DI fuel system.

 

[rwmurrayvt]

The system runs 2600psi of fuel pressure from the factory. Trust me, your boost level is irrelevant with the DI fuel system.

I was only quoting what was said in the video @9:22.

"Lobe on SI cam shaft is slightly taller that's boosting fuel pressure. Probably necessary to not overextend the duty cycle & may be necessary to overcome increased boost pressure."

If the upgraded turbo & the accompanying tune on the SI version cause a major increase in the combustion chamber's pressure pre-fuel injection, it may be necessary for the fuel pressure to increase to compensate. It's possible this little engine can handle significantly higher pressures than we expect. Then again, all I can do is (make educated) guess(es) because I don't have the equipment or experience that you do.

 

[VitViper]

I was only quoting what was said in the video @9:22.

"Lobe on SI cam shaft is slightly taller that's boosting fuel pressure. Probably necessary to not overextend the duty cycle & may be necessary to overcome increased boost pressure."

If the upgraded turbo & the accompanying tune on the SI version cause a major increase in the combustion chamber's pressure pre-fuel injection, it may be necessary for the fuel pressure to increase to compensate. It's possible this little engine can handle significantly higher pressures than we expect. Then again, all I can do is (make educated) guess(es) because I don't have the equipment or experience that you do.

That sounds like rambling and a theory not backed by any kind of practicality. Honda changed something and the guy is theorizing why -- ask the engineers. I've tuned DI motors into the 400whp+ power level on DI only and 500whp+ on DI+PI motors "only" running 2300psi of fuel pressure, combustion chamber pressure has never been an issue during the compression stroke. They might be trying to achieve a little better fuel atomization or reduce pump duty cycles, that might be something, and could be interesting.

 

[rwmurrayvt]

I certainly hope they have a design reason behind the change. Two possible reasons are to reduce duty cycle and to maintain/increase the delta p between the injected fuel/combustion chamber.

It's not really rambling. It's a fairly educated theory on why they made a change. I can't see them modifying an engine design for giggles.

 

[VitViper]

I certainly hope they have a design reason behind the change. Two possible reasons are to reduce duty cycle and to maintain/increase the delta p between the injected fuel/combustion chamber.

It's not really rambling. It's a fairly educated theory on why they made a change. I can't see them modifying an engine design for giggles.

I'm sure there is a reason -- but his original "theory" sounds like rambling to me. Been doing DI for 5 or 6 years now, and this car has one of the higher pressure fuel systems out of the box compared to other platforms... other platforms that are doing much higher boost and power figures. Whatever boost pressure change the Si may receive (2psi more maybe?) is such a minor change compared to a factory 2600psi fuel system (a factory fuel system that will run 3000-3100psi reliably, tested and tried )

 

[rwmurrayvt]

I'm sure there is a reason -- but his original "theory" sounds like rambling to me. Been doing DI for 5 or 6 years now, and this car has one of the higher pressure fuel systems out of the box compared to other platforms... other platforms that are doing much higher boost and power figures. Whatever boost pressure change the Si may receive (2psi more maybe?) is such a minor change compared to a factory 2600psi fuel system (a factory fuel system that will run 3000-3100psi reliably, tested and tried )

Based on your added input, I'm inclined to lean on the side of reliability engineering. Just because it can run 3k PSI doesn't mean it doesn't have an impact on the MTBF. I'd love to get to your shop some time if it wasn't all the way across the country.

 

[VitViper]

Based on your added input, I'm inclined to lean on the side of reliability engineering. Just because it can run 3k PSI doesn't mean it doesn't have an impact on the MTBF. I'd love to get to your shop some time if it wasn't all the way across the country.

It's possible, only Honda really knows. I've actually pegged this fuel system in the pressure relief valve, so I know what pressure it's at and the fantastic results that follow when you do it (and the cool sounds it makes, lol). I've been running other cars at at higher than stock fuel pressures for quite some time with no negative impact (to date).

So far when it comes to the DI pumps we have a couple camps:
- The DI pumps that are only good for stock power, and have huge pressure drops if you increase fuel demand at all.
- The DI pumps that are good for higher pressure only up to a point where the volume demand is too high, and then the pressure drops to OEM levels (at which point the volume it's able to supply is adequate and you run into no problems).
- Special sauce DI pumps that can do more pressure and a lot more volume than what the OEM runs it off the showroom floor.

So far the Civic pump is in the 3rd camp -- but I'll be testing that further after I have the upgraded turbo done and we can actually put some serious demand on it.

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