Boost help

[SMOKDU]

ok this is a head scratcher. I made 19 psi with a manual gauge on the dyno with a 4.0 whipple with tune/ mafia/ford racing exhaust stock headers / no cats/. 52lb. when i got home i only saw 10psi (found out later with the mafia the stock gauge will only show 10 psi. I then hooked up a two different manual gauges to see if that was the problem. made 13 maybe 14psi in second gear under load up to 7000 rpm and never dropped/ I then tried all of this in some order not all at the same time / put on a new Belt (its tight with good belt wrap) I then put on a new Bypass actuator from whipple/ I spayed brake cleaner around running engine to see if I have any vacuum leaks. We hooked up the Bypass with the boost solenoid off/added boost to the top of the bypass / zipped tied the bypass arm down with arm off bypass actuator so the computer or actuator can not open or bleed off boost. checked plugs to make sure engine is not hurt. (car runs perfect and has 20 plus vacuum. took off the air box and check K&N filters. made sure inlet tube could not collapse (has inlet tube sleeve)/checked intercooler pump/ checked blower on the car with belt off and it spins good and has no noise from hitting blades/ called Rich from Gt guys/ confirmed with the tuner all the settings are right/called whipple and they do not think it is the blower and said if it spins with no noise all should be good/ i am lost and i think i checked everything. The car does not smoke or pressurize the coolant system or over heat. cars sounds great but just feels like 13 psi. The only thing that is different is on the dyno the shell was up and on the street the shell is closed. can the shell restrict 5psi? the last thing unless someone else can give me some advise i am missing is to re dyno the car with the top up or take off the blower and look at the bypass blades but the car made 19psi so i am not sure why that would change. ok i owe someone huge if you can help because this is a three week adventure and I am burnt out. i checked way back in the archives neep heeeeelp.. lol i hate begging for help.

 

[nota4re]

1) Hope it was a typo - but DON'T spray brake cleaner anywhere around the engine!! Yikes! (Carb cleaner, OK... but NOT Brake Cleaner.)

2) My educated guess is that you have an intermittent restriction somewhere. Disassemble your aircleaner box and check filers and make sure you haven't sucked in a plastic bag or something. Also, make sure you have a reinforcement (Accufab) in your intake bellow to make sure it is not collapsing.

 

[SMOKDU]

1) Hope it was a typo - but DON'T spray brake cleaner anywhere around the engine!! Yikes! (Carb cleaner, OK... but NOT Brake Cleaner.)

2) My educated guess is that you have an intermittent restriction somewhere. Disassemble your aircleaner box and check filers and make sure you haven't sucked in a plastic bag or something. Also, make sure you have a reinforcement (Accufab) in your intake bellow to make sure it is not collapsing.

i know it was long but did all you said.

 

[BlackICE]

Did you check to see if your throttle blades open fully with the gas pedal is to the floor?

Do a datalog add see what your MAF counts are. They should be at least 920 to 960 counts with the Mafia on 75% when you are at 6500 RPM.

 

[SMOKDU]

Did you check to see if your throttle blades open fully with the gas pedal is to the floor?

Do a datalog add see what your MAF counts are. They should be at least 920 to 960 counts with the Mafia on 75% when you are at 6500 RPM.

did not do this and I can but we did not do anything to the throttle blade to change it. the boost read 19 and then just dropped after the dyno. whats one more thing at this point. thx at least that is a new idea. it is a cable not live wire so not sure what could happen. good thought will look at it

 

[paul b]

Just to verify, redo the dyno test exactly as before and check results.

 

[SMOKDU]

yes I am planning to do this again on the same dyno to see the boost and the numbers. you guys think you can lose that much boost thru the air box with the back closed? On the dyno the back was open. Rich wanted me to check the clamshell for blockage but I cant see anything stuck inside. I could take it off and go for a ride but do not like that idea yet.

 

[nota4re]

Where exactly are you reading boost from using the mecahnical gauges?

 

[SMOKDU]

Where exactly are you reading boost from using the mecahnical gauges?

did all that stuff above including using two different manual gauges just in case one of those were wrong. thx sooner or later I will get the "that's it" I hope lol.

 

[BlackICE]

yes I am planning to do this again on the same dyno to see the boost and the numbers. you guys think you can lose that much boost thru the air box with the back closed? On the dyno the back was open. Rich wanted me to check the clamshell for blockage but I cant see anything stuck inside. I could take it off and go for a ride but do not like that idea yet.

You can remove the J ducts to see if mice built a nest in there. Just a few T27 screws. I remember another owner had a nest in the airbox.

 

[SMOKDU]

You can remove the J ducts to see if mice built a nest in there. Just a few T27 screws. I remember another owner had a nest in the airbox.

I removed the air box but have not yet removed the backing off the rear shell. looked inside the ducts from the outside and it looks clean. I need to put car back on dyno with the shell up again to see if that's it.

 

[peiserg]

did you reinforce your air inlet? That thing collapses even with just a pulley.

 

[SMOKDU]

did you reinforce your air inlet? That thing collapses even with just a pulley.

Yes did this also has tube inside. Thx anyway

 

[fjpikul]

Check plugs and wires? All cylinders firing?

 

[MTV8]

Are you certain that the boost gauge used while on the dyno was accurate and hooked up to the same port used for subsequent testing? How much power did the car make on the dyno?

 

[SMOKDU]

Are you certain that the boost gauge used while on the dyno was accurate and hooked up to the same port used for subsequent testing? How much power did the car make on the dyno?

Ok after 3 long weeks I'm getting somewhere. The rest of the story. Ok without using any names I used two diff tuners . The first tuner tuned the car and on the Dyno it made 19 psi and made good but not great power. On the test drive the car ran good but in first gear after tires broke loose would breakup and miss when short shifting into 2nd causing a check engine light for misfire . I have a BAP installed and.(JMS unit)turned all the way up. After 2 weeks We could not find out the issue and thought the JMS was wired wrong or I needed 2 BAPS. After 2 weeks of getting knowhere and having cels coming on I decided to go a different derection. I raced boosted fords for 10 years and know a lot of tuners persnally and ask someone skilled in sct tuning to help me. The first line of order was to figure out the misfire at low RPM after redline. Turns out he had this issue before on Shelby mustangs because these cars both have return less fuel rails . We tuned off the BAP and did a first to second pull and the hesitation was gone. The problem with fuel pressure spikes with the BAP turned all the way up. At this point I wanted to call it a day but the car was tuned with the BAP on 100% so we dynoed the car again with a new tune not using the BAP. On the first pull on the Dyno the only made 4psi. I was like wtf now. The tuner did some magic and switched the vacuum lines to make sure the computer could not open the bypass and we made another pull. Now with more boost, and 20 more hp then the tune using the BAP I was not complaining and .the AF was fine so I thought why use the BAP anyway. Not wanting the vacuum line hooked up wrong we switched them back and the tuner turned off any controls to opening the bypass by itself. Ok here is when the fun started . After i got home I wanted to drive the car with the higher hp but noticed the car felt slower then the first tune and looking closer the boost was only 10 psi. Now read the first post. I did all the problem solving issues and came up dry every time. Last night I was thinking ok pull the blower off and look at the bypass under the blower or load the first tune even though the tuner said no way it is the tune. I loaded the tune and BAM the gauge pegged at 15psi and the car was back. The factory gauge even though I was told it would not show more then 10psi was and it feels like Its a way faster car again. Here is the issue the drivability is better with the BAP off and my tuner still thinks it is not the tune, I just need both tunes merged hehe. Or I have a issue still . Confused but boost is back for now. Can this be the tune ? And why with the mafia my gauge peg at 15 psi when i was told it should only read 10 psi? I do not want to offend either tuner I just want it right.

 

[Waldo]

...I just want it right.

Call Torrie.

 

[MRL]

First off, I would get in touch with someone who actually knows what they are doing tuning wise. Torrie has obviously tuned a pile of these cars and would be a fine choice....Do not be afraid of remote/email tuning. Guys like Torrie, and a select few other have this process down pat, and can achieve the same results as if they were with the car in person.
Second....which adds to the first....I have tuned several cars in the 1000hp range using a returnless fuel system and a BAP wired full on. Randomly turning stuff off in the calibration is usually not a good idea (although sometimes it is required)....

As for the stock boost gauge, that is an inferred reading. There is no actual boost source to the gauge, it's just calculations. The best, and most acurate way is to log boost on the dyno with a properly calibrated external MAP sensor.

Troubleshooting the problem should not be that difficult. It's easy to figure out what the blower should be making for boost based on the pulley ratio...if it isn't making that there are only a few reasons why.
Restriction, either on the inlet or the outlet.
Bypass valve....this is easy to test....manually wire the bypass closed on the dyno
A boost/vacuum leak

So, like mentioned, find a trusted tuner familiar with these cars....listen to his advice....and just double/tripple check the few mechanical things that could be causing the issue.

Good luck.

 

[SMOKDU]

Call Torrie.

The tuners I'm using are the best in both areas and I value what they say but I can't find anything wrong with what they want me to check. I feel like I have some issue that should be black or white but all the tips they give me come up dry. It feels like I am not finding the issue and i think I am letting them down but I.can't find any issue . One guy thinks vacuum leak checked that and rechecked it . No way its vacuum and one thinks BAP issue and both JMS and I can't find an issue. I drove the car for 2 hrs last night using the first the tune car makes power but has small tune issues. One being a idle hunt and stalled once. The other tune runs great no issues but makes less power and boost on the gauge.

 

[paul b]

Do you have the ability to reload the stock tune? Just as an aid to see if you have a tune problem or possibly a mechanical problem. I don't know if that makes sense but it seems a source of more information toward the mystery.