I have a problem and I need help!

[TheManInBlack]

okay here it goes, i have a 2002 Mustang GT with an Vortech SQ with the stock pulley. other mods are, 75 mm TB, long tube headers etc.

heres my problem...when to make a dyno pull.. the power was down..and i mean way down. it put down around 280-290 (mustang dyno). this is my first car ive done a supercharger mod to. the kit supposedly had 3k on it and it looked like it. it looked brand new. anyways, my boost gauge shows around 3.5 psi at around 3500rpms. me being a person not super knowledgeable of centri style blowers i expected the boost to start building at a higher rpm. i was told by the shop where it made the dyno pulls that it should start building boost at a lower rpm...closer to 2200rpm range. the car was in great shape motor wise. felt plenty strong before the supercharger install. it does have a lil bit high of mileage (about 100k) but it didnt smoke or anything. felt as good as it did when i bought it and it had 60k on it. we checked to see if the clutch is slipping and its not. we are gonna do a compression check tomorrow on it to see what that comes to. its hard for me to believe that the motor would loose compression. im open for ideas of what i should check on it. also the kit came off a 99 model GT. correct me if im wrong but the only difference is the main bracket which i gotten one for a 01-04 car.

 

[Jon98Stang]

Well the Centrifugal blowers should be creating boost around 1900 or so and the Standard Blowers ( on top of motor ) Are about 1700.. Mistake me if im wrong. Umm.. What kinda tune do you have for it? I don't see much of a problem. How much boost did you run at the end of the dyno?

 

[TheManInBlack]

its an sct custom tune....weve been chasing problems back and fourth. before this problem, my svt focus pump was at max duty cycle at 4500 rpms. so i bought a kenne bell bap. now that the fuel is fixed...we ran into this problem. the boost at the end of the pull, that i do not know. i think on the last pull they didn't push it past then because of them thinking the boost was too low for the rpm. we are gonna look at it some more tomorrow. seems a lil low at 3500rpms to have 3.5lbs of boost. ill know more tomorrow after some more diagnostics

my lack of knowledge of supercharged cars is really hurting me at this point.

 

[TheManInBlack]

we changed the bypass valve on it and that seemed to have brought my boost back. the figures i gave in my first post of 280-290 were incorrect. on that pull it made around 250rwhp. after the bypass swap it gained back all its boost and put down 285hp/300tq. now for reference, most people use dynojets. mustang dynos show around 15% less than the dynojet counterparts. thats what the mustang dyno rep said when he came to set up this one. so for the sake of numbers...that puts me around 330rwhp. does this sound right?..i sorta figured it would do around 360ish to the wheels. if my boost is there and it does that power amount then my motor is tired. the clutch isnt slipping despite it being a ford clutch with 100k on it. maybe the precentage is more than 15% difference. im gonna take it the track next sunday and see what numbers it pulls and datalog it.

is my power level about right for a stock pulley and minor bolt-on 99-04 2v?

 

[meaty mac]

still very low

 

[SonicBlueGT1]

im no supercharger expert either but ive seen alot of cars on here with the same mods puttin down close to 375-400??

 

[bullitt1289]

how much boost are you running now with the bypass fixed?

 

[TheManInBlack]

we are looking at around 6-7psi. a guy on modular fords told me a friend of his running that boost level put down 333rwhp. so at that boost level it must be right. my tune may be on the safe side which could have cut 10-15hp of the dyno numbers. only difference between my car and that guys friends car was i have LT headers. when u have heads that also double as a boat anchor..headers cant give you awesome gains.

 

[ponygt65]

With teh freeflowing exhaust you will have a tad less PSI than most with your setup. Also, your HP levels depends greatly on what the tune is at....timing and fuel. I do know that the 2V GT's need roughly 10 psi to put down 400. With only 6.5, you seem about right.

What is your A/F and timing?

 

[TheManInBlack]

a/f is bout 12.0 and the timing is like 14-15..the tuner told me that he wasnt liking the 180 degree ACT at the end of the pull so he has it to cut timing when it reaches and or goes beyond that temp..

i wondered if the 75mm/plenum and headers would kill boost a bit..so that is true then?

 

[CHC speed]

I have a 2000 mustang with a procharger running 7 psi and made 380hp and 365 tqu. Had a lot of problems with running rich and only made 300hp or so. do you know air/fuel. I am running 10.5 to 11.

 

[TheManInBlack]

im running about 12.0 with 14-15 degrees timing...i think im about right power wise with 6-7lbs on mine from what ive read and people ive talked to on different message boards..we will see sunday what she does on the strip..

 

[CHC speed]

12.0 is great. 11s or so is a safe place to start.I just know when I had it below 10. it made little power.