whipple 4.0
- Thread starter kumar
- Start date
Fubar
Totally ****** Up
It also has a top pressure line that is suppose to close it when it sees pressure. I have been wondering if that is malfunctioning. We will see shortly.
Fubar
Totally ****** Up
I have another piece to this puzzle. Upon completing a few test runs with the valve zip-tied closed, I could not reproduce the boost-loss issue. That certainly points to a diaphragm problem. This is the replacement diaphragm so I doubt I received two defective diaphragms.
Thoughts?
Thoughts?
Air box is a restriction? Evolution performance has a few Gt500 cars making 858-860 rwhp with the 3.4 on race fuel, i don't see why the Gt won't do it at 23lbs of boost. Maybe they will, who has made the most power with a whipple GT?
Btw Take the clamb shell off and flip the air box upside down and drive it with no filters and see what happens. I don't think there is enough volume through the factory two holes in the air box for a whipple as it requires absolutly no restiction to the throttle body to make power. A turbo or Centrifical do not have the same inlets needs as a twin screw. Also i would imagine there is enough volume in the intake box to make power/max boost till you go through a couple gears. Another thing todo would be too make a oval steel insert the same as the airbox and stick the mass air flow sensor in it, then take the air box off and put a big conical filter on the steel sleeve and see what happens. The whipples on the Gt 500's are using a 5'' round tube as a meter and alot of volume up to the t.b. I see this as a problem on the whipple GT's. These cars should make 900rwhp with a whipple on race gas at 23-5 lbs of boost.
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Rockstar
GT Owner
I to do believe that the factory air box may be a restriction. I have been talking about this subject for weeks. I guess it is time to play with the air box.
I just recieved my 4.0 and OOOOOOHHHHHH it is COOOOOL! I cannot waite to bolt it on and and consume some mass quantities of fuel. It won't be untill next week because I am waiting for some additional parts.
But I will keep all of you posted on how this thing blast's in the Rocky Mountains! :eek
I just recieved my 4.0 and OOOOOOHHHHHH it is COOOOOL! I cannot waite to bolt it on and and consume some mass quantities of fuel. It won't be untill next week because I am waiting for some additional parts.
But I will keep all of you posted on how this thing blast's in the Rocky Mountains! :eek
soroush
Ford Gt Owner
- Aug 8, 2007
- 5,256
FYI when we dyno'd my car with the whipple on the 23lb pulley, we had a vacuum gauge on the inlet tube (to the throttle body) and found no pressure change, so there was no draw what so ever. the airbox was not an issue, anyone can easily reproduce this test.
Rich,
Can you share some thoughts - as it sounds like many of us on here will soon be facing perhaps some of the issues FUBAR has uncovered with the 4.0Litre.
Would be good to keep this stuff a team effort as we pull in more data and findings?
Thanks!
Whipple
I don't know if this will fix the issue at hand but it has corrected the problem for two other folks I have had to talk through their issues. One had a bad vac harness and they just swapped out the harness. That took care of the intermitent loss of boost issue on that car so we don't kow if it was a bad fitting or check valve. The other car was were the rubber upper vac fitting on the bypass valve was pushed on too far to the fitting and not allowing the vac to enter into the bypass diaphram. Kind of like sucking air through a straw and putting your had over it, but if you pulled your hand back a bit air could pass through.
Now this may or may not be the issue at hand but it is just what we have helped others with when someone else did the install.
Just for reference the top port just uses engine vac. The solenoid and the vac reservoir is for when the ECU wants to dump boost (because of high intake air temp IAT2). This is why the cars loose a lot of power when they overheat, it is the ECU's way of protecting the car. The oneway check valve is so when you are at full throttle (no vac) and the ECU wants to dumps boost it will command the solenoid to switch to source the vac from the reservoir. The valve is there so there will always be vac stored in the resevoir. The other port on the bypass is another protection mode. It is in case there is a restriction (very, very dirty air filters) in the air box assembly. It will actually cause a pressure causing the bypass to open and therefore dumping boost again because for whatever the reason the engine won't get enough air. This setup is the same setup that we used on the 99 Lightning, 03 Cobra, and the GT500.
I don't know if this will fix the issue at hand but it has corrected the problem for two other folks I have had to talk through their issues. One had a bad vac harness and they just swapped out the harness. That took care of the intermitent loss of boost issue on that car so we don't kow if it was a bad fitting or check valve. The other car was were the rubber upper vac fitting on the bypass valve was pushed on too far to the fitting and not allowing the vac to enter into the bypass diaphram. Kind of like sucking air through a straw and putting your had over it, but if you pulled your hand back a bit air could pass through.
Now this may or may not be the issue at hand but it is just what we have helped others with when someone else did the install.
Just for reference the top port just uses engine vac. The solenoid and the vac reservoir is for when the ECU wants to dump boost (because of high intake air temp IAT2). This is why the cars loose a lot of power when they overheat, it is the ECU's way of protecting the car. The oneway check valve is so when you are at full throttle (no vac) and the ECU wants to dumps boost it will command the solenoid to switch to source the vac from the reservoir. The valve is there so there will always be vac stored in the resevoir. The other port on the bypass is another protection mode. It is in case there is a restriction (very, very dirty air filters) in the air box assembly. It will actually cause a pressure causing the bypass to open and therefore dumping boost again because for whatever the reason the engine won't get enough air. This setup is the same setup that we used on the 99 Lightning, 03 Cobra, and the GT500.
Fubar
Totally ****** Up
I bet this is it. We are pulling more air than ever before. If I simply disconnect the bottom vac line, that should sufficiently test this as a culprit.
rydog143
GT Owner
boost problems
have 4.0 whipple with heffner exhaust now can get over 10lbs of boost. Came to fourm and i see there is a problem. I tryed ever thing that they have talked about here with no luck .Car is missing some power now, big difference between 19lbs an 10lbs of boost still fast but not like it was before . Wow hope its a easy fix, big bucks to invest to have a problem like this. Might try air boxbox but why are proplems starting to happen now? Please would like to here the fix thanks
have 4.0 whipple with heffner exhaust now can get over 10lbs of boost. Came to fourm and i see there is a problem. I tryed ever thing that they have talked about here with no luck .Car is missing some power now, big difference between 19lbs an 10lbs of boost still fast but not like it was before . Wow hope its a easy fix, big bucks to invest to have a problem like this. Might try air boxbox but why are proplems starting to happen now? Please would like to here the fix thanks
- Aug 25, 2006
- 4,436
If you have the OEM boost gauge and the Whipple with a Mafia scaling the MAF then the boost gauge will not be reading the correct value; you may in fact have nothing wrong.
Takes care
Shadowman
rydog143
GT Owner
4.0 whipple
not the gauge it use to dip below 15 pounds and be scary fast now only see it go to 10 think my 08 viper with headers is as fast now
not the gauge it use to dip below 15 pounds and be scary fast now only see it go to 10 think my 08 viper with headers is as fast now
Fubar
Totally ****** Up
It sounds like your bypass valve may be open too. Try to zip tie it down, then give it test. If nothing changes, at least you will be able to eliminate that as a possible problem.
I am going to do some more testing today, then I will have more information. I will report what I find.
I am going to do some more testing today, then I will have more information. I will report what I find.
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Fubar
Totally ****** Up
I replaced my bypass valve and it did not solve the problem. It is possible that I received a second faulty valve but that seems unlikely.
Here is a piece of good news. After discussing the issue with Rich, Dustin and Shawn, I think we all believe that strange things are happening in the intake tube (ie:massive vacuum). However, the particular problem I am having points to a bypass diaphragm problem. So, I disconnected the bottom vacuum line from the bypass diaphragm. This is the line that connects to the intake tube. After a few test runs I could not reproduce the boost-loss issue.
Now this solution is not immediately logical as vacuum in that line should help the valve close but I can not argue with the results. My suspicion is that the bottom vacuum lined created an uneven downforce on the bypass diaphragm and this cause the diaphragm to bind-up and/or not close properly.
I am going to run the car like these for a while and test this solution. I will keep the forum posted if anything changes.
Regards,
Mark M.
Here is a piece of good news. After discussing the issue with Rich, Dustin and Shawn, I think we all believe that strange things are happening in the intake tube (ie:massive vacuum). However, the particular problem I am having points to a bypass diaphragm problem. So, I disconnected the bottom vacuum line from the bypass diaphragm. This is the line that connects to the intake tube. After a few test runs I could not reproduce the boost-loss issue.
Now this solution is not immediately logical as vacuum in that line should help the valve close but I can not argue with the results. My suspicion is that the bottom vacuum lined created an uneven downforce on the bypass diaphragm and this cause the diaphragm to bind-up and/or not close properly.
I am going to run the car like these for a while and test this solution. I will keep the forum posted if anything changes.
Regards,
Mark M.
Thanks Mark!!
Yes please keep us all posted as it's beginning to sound like we are all going to have similar issues until we come up with a robust solution - I am sure it will all be worth it in the end and we will have the best possible power from a Supercharged GT engine.
On another note - what other mods do you have to your engine?...are you running headers or just a CAT-back??
Thansk again! You are our pioneer!
Did the new valve ship to you with a actuator adjustment tool? Was it straightforward to properly adjust the actuator? Proper adjustment is essential.
Exactly. As the solenoid is controlled by the ECU (to afford the protection as Rich suggests), it also begs the question if, on a modified car, the ECU "sees" what it believes is an over-boost condition and tries to save itself. In short, maybe there's additional programming that can be done so the ECU isn't the culprit that is pro-actively taking boost away from you.
I know you are just testing and eliminating variables, but long term I would not recommend elimination of the bypass valve as its primary function is to eliminate SC cavitation.