How to scale the HPFP pressure sensor

[Realgib3]

DJ, just another point to help your case that the spill valves don't need to be touched. We talked about it before but, with my KMD internals I saw near 2100psi, but it was only durring FFS which pretty much mimics the start-up situation where lots of fuel is going to the rail will little injected...so my only concern is that blocking it off completely will be too much pressure for those types of situation. WOT though I have no doubt that blocking it off will net good results....If you can flow enough air...

[cld12pk2go]

Originally Posted by djuosnteisn I think a few of you are missing some critical details. There are 2 valves used to regulate pressure. 1) The internal, solenoid controlled spill valves. This are the primary source for pressure regulation. 2) The emergency over-pressure relief valve, whom i'm butting heads with right now. Before i ever put my ckt on, with the hpfp, the system NEVER relied on the relief valve. You can hear it when it opens, just ask skater. And the internal spill valves work so well that they can regulate down to ~400-500psi even at higher rpms (cam driven pump) with light throttle. So if anything, by "upping the pressure", these spill valves will have to work even less to regulate pressure. I really think the relief valve is like an airbag, not a seat belt. It's not intended to be a critical part of the regulation process, but more so a fail safe to keep the rail from reaching damaging pressures (3k+). When john blew up a rail, he was mucking with the internal spill valves, and had fully blocked this relief valve. I'm not gonna touch anything internal, cause i believe the ecu controls it fine. So i think my logic stands. I've never heard the relief open w/out my ckt, and that means the spill valves are flowing much more fuel upstream than it would be when running the rail at a higher pressure. ...double post merge... Think of it like this, imagine that silver had already sourced a new valve that doesn't open until 2500psi... How is that any different that just blocking it off. It isn't unless a high pressure event occurred, which from my experience, doesn't.

Removing the RV is simply removing a layer of defense designed to prevent exceeding the system's designed pressure. It can be a workable method, but probably increases the probability of failure by orders of magnitude.

For example, I have logged over 2000 PSI often on decel. So it is likely that I am lifting the RV. If that isn't available the pressure will spike much higher before the spill valve will open sufficiently to account for the rapidly decreased flow to the injectors...

Good luck, but I would be very careful when proceeding.

A higher rated RV will be a sweet improvement.

[djuosnteisn]

Yeah, that's real interesting. 2.5V is alot. I wish you could measure the voltage directly while doing that.

Even if it works, i would have to guess that the relief valve was open that whole time, and you were probably overwhelming it. I'm not sure if that would be hard on the pump or not, cause as i understand it, the pump generates all that pressure anyways, and bleeds it off with internal spill valve.

I also remember Whoosh saying something about the ms3 & ms6 being "different". Not sure if it has any relevance to this or not.

Damn, now you have me all boggled, hahaha.

How are all you 3's seeing higher than 1900psi? Seriously, it seems weird. My shit won't go 10psi over that relief pressure.

[SilverDemon]

To achieve the voltage off set the sensor deviation set point was -75% on the SB pressure table. I only did that once, it kind of scared me a little lol!! I am not sure what would be the difference in the speed 3 and 6, since I have no one near me with a speed 6 and a SB to compare.

[djuosnteisn]

I'm starting to wonder if the speed3 relief valve is different than the 6.

Socks, there's no way your valve could be from a speed6, right? Cause originally you were unable to build higher pressure.

[Lex]

On decel you will see higher pressure since the relief valve has to flow ALL the fuel since none of it is being injected. That's why you see the spiking.

[djuosnteisn]

I just pulled up an old log with ckt at minimum (essentially not ckt), and i do see 2250 on decel.

And i guess spill valves wouldn't alleviate any of that, but they could (and i'm sure they do) open up as soon as possible to minimize the spike. So whatever is pumped into the rail would have to stay in the rail until injectors start spraying again.

Ugh, maybe i'll just try to reduce one of the hole sizes by half or so and try that before i go complete block off.

[cld12pk2go]

Originally Posted by djuosnteisn I'm not sure if that would be hard on the pump or not, cause as i understand it, the pump generates all that pressure anyways, and bleeds it off with internal spill valve.

The pump moves a certain volume. The pressure at its discharge is dependent on the amount of volume going to the injectors/spill valve/RV. Too little open flow area to these results in higher DP to move the volume the HPFP is putting out.

If one of these changes suddenly (like on decel the volume to injectors goes to zero rapidly), then the spill valve PID loop will have to see the pressure increase and start to open to correct the over pressure setpoint condition. If this is too slow, then the RV will open preventing system damage.

The stock spill valve tuning is currently configured to work with the stock HPFP output volume. This tuning is slow to respond to the increased volume generated by the aftermarket HPFPs thus resulting in pressure spikes and RV lifting events. If we gain access to the spill valve PID loop, then we can make the tuning more aggressive to account for the 40% increase fuel volume with aftermarket HPFPs.

FYI, when designing these types of systems, it is never desired for the RV to actually lift during normal operation. The RV's purpose is to protect the system against abnormal conditions.

[cpolly69]

Not to thread jack, but I am as interested in how CPE is doing their now found magic as the next person and the ? was raised by DJ about what the SB is doing. The SB can only manipulate what it's intercepting, so I took a second and went thru all the connections it has in the instructions. I could list them all, but the only ones that apply or I don't know what they are - are 2r (actual fuel pressure sensor) 2ak (throttle body), and 1be (which is relay F36 - I don't know what that relay is - I'll figure it out later)
But maybe since CPE's new trick involves flashes (they always have done a combo of flashes and piggyback for all you piggyback haters) that insert new values for these spill valves you guys are discussing????

[Lex]

The mechanical valve can't be defeated electronically.

The SB can play with fuel pressure by manipulating the sensor just like we are. No more magic than that.

[cpolly69]

Originally Posted by djuosnteisn I think a few of you are missing some critical details. There are 2 valves used to regulate pressure. 1) The internal, solenoid controlled spill valves. This are the primary source for pressure regulation. 2) The emergency over-pressure relief valve, whom i'm butting heads with right now. Before i ever put my ckt on, with the hpfp, the system NEVER relied on the relief valve. You can hear it when it opens, just ask skater. And the internal spill valves work so well that they can regulate down to ~400-500psi even at higher rpms (cam driven pump) with light throttle. So if anything, by "upping the pressure", these spill valves will have to work even less to regulate pressure. I really think the relief valve is like an airbag, not a seat belt. It's not intended to be a critical part of the regulation process, but more so a fail safe to keep the rail from reaching damaging pressures (3k+). When john blew up a rail, he was mucking with the internal spill valves, and had fully blocked this relief valve. I'm not gonna touch anything internal, cause i believe the ecu controls it fine. So i think my logic stands. I've never heard the relief open w/out my ckt, and that means the spill valves are flowing much more fuel upstream than it would be when running the rail at a higher pressure. ...double post merge... Think of it like this, imagine that silver had already sourced a new valve that doesn't open until 2500psi... How is that any different that just blocking it off. It isn't unless a high pressure event occurred, which from my experience, doesn't.

What was DJ talking about here when he said the ecu controls them fine.....

[djuosnteisn]

That's the spill valve. It's ecu controlled via a solenoid.

Lex is talking about the mechanical valve, which is a over-pressure relief valve, and has no ecu control.



I'm very upset right now, and going to start drinking beer. I took a pill and welded the hole up nicely, leaving about half the area, and then ground down enough threads so part of the pill would stick down into the un-tapped section of the bore, so the relief valve would thread all the way in.

Test fit it in my spare rail, and both threaded in perfect, so it looked like a winner. But when i was unthreading the pill, somehow it got cross threaded, and fucked up my spare rail.


I'm not happy right now at all, and i'm not keen on risking damage to the rail on my car. Plus, even if it did fit, this solution is still a kludge (border line fail). Say we put a restrictor pill in there small enough to "hold higher pressure" while at wot, what happens when i let off the throttle and go into decel. The peak pressure are going to be much much higher than normal.

Ideal solution at this point is a drop in replacement valve that doesn't open until 2300psi, IMO.

[mkriebs]

I think thats the best way to do it DJ. I would hate to see your car get messed up, or anything dangerous happen.

[SilverDemon]

Sorry to hear DJ I will work on getting us what we need.

[SilverDemon]

I have some news that I would like to pass on to the community. Both DJ and myself have been working on getting a higher pressure relief valve, and we have contacted several companies in our quest to find what we need. Most of the valves that we have seen has been too big and well over $250.00. The vendor that contacted me today gave me a quote for a valve that can be factory set at 2300psi (+ or - 4%), and is smaller than the rest of the valves. The best part of this is, the valve and manifold block will be about $72.00. I want to stress that this part is still a big maybe as to how well it will fit into our application. But, this is the best news that I have heard to date.

[superskaterxes]

whats a manifold block?

btw great news!!!!

[cld12pk2go]

I assume that the Cobalt folks have an RV in their system as well. Can you just use theirs with perhaps an adapter piece or two?

I understand they are running up to 2700 PSI...

[djuosnteisn]

I'm not sure if we'll need the manifold block. I would think the valve would just thread straight into the rail, or into an adapter in the rail.

Great find Scott!

*double post merge with a pictar*

[SilverDemon]

Originally Posted by superskaterxes whats a manifold block? btw great news!!!!

This is a two piece design, the valve body, and a block that has ports used for pressure in and pressure out.

Originally Posted by cld12pk2go I assume that the Cobalt folks have an RV in their system as well. Can you just use theirs with perhaps an adapter piece or two? I understand they are running up to 2700 PSI...

I have not seen, or for that matter never thought of it. I also do not know what their factory RV is set to, or what they have used in place of the OEM.

Originally Posted by djuosnteisn I'm not sure if we'll need the manifold block. I would think the valve would just thread straight into the rail, or into an adapter in the rail. Great find Scott!

This is a cartridge that is fit into the manifold with ports for in and out. But, with some thinking, a more streamed line version of the manifold could be made. I will know more once i can get my hands on one of these bad boys.

[djuosnteisn]

Oh snaps, i see exactly what your talking about. Yeah, we'll see what you think when you get it.

Thanks again man!

[mkriebs]

We are still using the stock RV, we simply tune for the pressure increase (THANK GOD!). We do run to 2750 psi, I THINK we can go farther, but no one wants to push it too much in case of fuel rail failure. No one needs much more pressure than that yet, so we will see when the pioneers get over 550whp...

[SilverDemon]

Originally Posted by mkriebs We are still using the stock RV, we simply tune for the pressure increase (THANK GOD!). We do run to 2750 psi, I THINK we can go farther, but no one wants to push it too much in case of fuel rail failure. No one needs much more pressure than that yet, so we will see when the pioneers get over 550whp...

Pics or link to the said RV for the Colbalt's......If it is anything close to ours, then it would so much easier...

[mkriebs]

I honestly don't have a clue where it is on the engine, lol. Its so packed in our engine bay its not funny, plus i have never had a reason to look for it. If I get to the shop on Friday, I will take a look at our engine on the stand.

[Deadman]

google may be your friend? Google search for the RV on the LNF motor !

[SilverDemon]

That would be great, I have tried to do searches for the RV on Google, but Google just looks at me like I am an idiot.....LOL!!

[mkriebs]

Yeah, I think I am stopping by the shop Friday, got an appt at school so I'll be around there.

[SilverDemon]

I think I just found the answer.....It seems to integrated in to the fuel pump.

I pulled this from redline forums:
High Pressure Fuel Pump
The high pressure fuel pump is a mechanical one cylinder design driven by an additional three lobe cam on the camshaft. High pressure fuel is regulated by the fuel rail pressure (FRP) regulator, which is a part of the high pressure fuel pump. The FRP regulator is a magnetic actuator which controls the inlet valve of the high pressure pump. The ECM provides battery voltage on the actuator hi circuit and ground on the actuator low circuit. Both circuits are controlled through output drivers within the ECM. When deactivated, both drivers are disabled and the inlet valve is held open with spring pressure. When activated, the actuator low circuit driver connects the low circuit to ground and the actuator hi circuit driver pulse-width modulates (PWM) the hi circuit. The ECM uses the camshaft and crankshaft position sensor inputs to synchronize the FRP regulator with the position of each of the three camshaft lobes. The ECM regulates fuel pressure by adjusting the portion of each pump stroke that provides fuel to the rail. The high pressure fuel pump also contains an integrated pressure relief valve.

Fuel Rail Assembly
The fuel rail assembly attaches to the cylinder head. The fuel rail distributes high pressure fuel to the fuel injectors. The fuel rail assembly consists of the following components:

• The direct fuel injectors
• The fuel rail pressure (FRP) sensor
Fuel Injectors
The fuel injection system is a high pressure, direct injection, returnless on-demand design. The fuel injectors are mounted in the cylinder head beneath the intake ports and spray fuel directly into the combustion chamber. Direct injection requires high fuel pressure due to the fuel injector's location in the combustion chamber. Fuel pressure must be higher than compression pressure requiring a high pressure fuel pump. The fuel injectors also require more electrical power due to the high fuel pressure. The ECM supplies a separate high voltage supply circuit and a driver circuit for each fuel injector.

The fuel injector assembly is an inside opening electrical magnetic injector. The injector has six precision machined holes that generate a cone shaped oval spray pattern. The fuel injector has a slim extended tip in order to allow a sufficient cooling jacket in the cylinder head.

Fuel Injection Fuel Rail Fuel Pressure Sensor
The fuel rail pressure sensor detects fuel pressure within the fuel rail. The engine control module (ECM) provides a 5 volt reference voltage on the 5 volt reference circuit and ground on the reference ground circuit. The ECM receives a varying signal voltage on the signal circuit. The ECM monitors the voltage on the FRP sensor circuits. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low.

[djuosnteisn]

This bitch probably knows where it is:

[SilverDemon]

I hate to say it, but the Colbalts have a better design and control over the fuel pressure than we do.

[superskaterxes]

dustin your the dirtiest sluttyest picture whore ive ever seen.

[Deadman]

can we overcome the better design by the cobalts?? Can we gain this design somehow!? haha

[cpolly69]

Originally Posted by SilverDemon I hate to say it, but the Colbalts have a better design and control over the fuel pressure than we do.

YouTube - Surprise Surprise Surprise

YouTube - Surprise Surprise Surprise

[SilverDemon]

It would be nice. Their setup seems to let the ECU control the fuel pressure regulator (from what the article I found).

HAHAHA!!! Funny Chris!! smart aleck

[djuosnteisn]

Our ecu has a similar control function.

I can measure it one day if i ever get some time.


By the way, my work gave me a broken 4 channel scope today cause it has a broken back light. So when i fix it, i'll be able to measure anything anyone wants (not body parts, cause i need more than 4 channels for that ).

[cld12pk2go]

Damn, I thought I was on to something with the LFN RV.

The next step could be to look at every other DI motor RV and hope something is close.

What about the new Taraus Ecoboost for example?

Most industrial RVs are way larger (and more expensive) than what we really need.

[Lex]

Anyone look into hydraulic applications? Hyd PRVs are common:

Hydraulic Relief Valve,Hydraulic Relief Valves,Hydraulic Relief Valve Manufacturer

Adjustable Pressure Relief Valves - Hydraulic Supply Co.

[mkriebs]

Silver, I found that article right as I was walking out the door, lol. 1st google result haha.

I honestly think that the $72 valve silver demon found would be great for you guys. You likely are not going to be able to find an OEM piece for that price. If the Balt piece was not integrated (which I am not entirely too sure how they use the term 'integrated'), its price would be ridiculous from GovernMENTAL Motors. Every piece for this engine is insanely priced, or not available.

But, as a consolation, you could check your local Ferrari dealer, since the new California uses the same DI pumps as the Cobalt... meaning my Cobalt is a Ferrari. *AHEM*

[cld12pk2go]

Originally Posted by Lex Anyone look into hydraulic applications? Hyd PRVs are common: Hydraulic Relief Valve,Hydraulic Relief Valves,Hydraulic Relief Valve Manufacturer Adjustable Pressure Relief Valves - Hydraulic Supply Co.

I just spend 30 min going through Mcmaster-carr and Grainger and didn't find anything suitable...

I did find some small industrial inline relief valves with NPT fittings, but the were $300+


Silver, got a link to the $72 RV?

[SilverDemon]

Originally Posted by Lex Anyone look into hydraulic applications? Hyd PRVs are common: Hydraulic Relief Valve,Hydraulic Relief Valves,Hydraulic Relief Valve Manufacturer Adjustable Pressure Relief Valves - Hydraulic Supply Co.

This is where the primary search is, hydraulic applications. In fact DJ found the first source from HighPressure.com This was the place that had an adjustable valve, but it was almost 8" long and 2" in diameter and was over $280. This RV I found is from Sun Hydraulic, more compact, non adjustable, and way more inexpensive. Let me get one on order, it will take about 2 weeks, then we can go from there.

Originally Posted by cld12pk2go I just spend 30 min going through Mcmaster-carr and Grainger and didn't find anything suitable... I did find some small industrial inline relief valves with NPT fittings, but the were $300+ Silver, got a link to the $72 RV?

Sun Hydraulics part reference for the cartridge is RDDA-CAV when I order the part I will specify 2300psi, with the custom pressure setting the cartridge will cost $52.58

Manifold block is: FAB and it runs $18.86

[hnda etr]

Originally Posted by SilverDemon This is where the primary search is, hydraulic applications. In fact DJ found the first source from HighPressure.com This was the place that had an adjustable valve, but it was almost 8" long and 2" in diameter and was over $280. This RV I found is from Sun Hydraulic, more compact, non adjustable, and way more inexpensive. Let me get one on order, it will take about 2 weeks, then we can go from there. Sun Hydraulics part reference for the cartridge is RDDA-CAV when I order the part I will specify 2300psi, with the custom pressure setting the cartridge will cost $52.58 Manifold block is: FAB and it runs $18.86

Before you buy, check out this thread for PTP's Rail relief (check valve) valve

http://www.mazdaspeedforum.org/forum/foru...1-2-3-a-45853/