Chasing the Procharger flatline

[SolarFlare]

Thats true but a couple of things on that 601/492 dyno. I was running 8.5psi on 93. My graph did not drop off like yours at 6500. It more or less flatlined with a slight upward direction. I would verify your boost..if you are truly at 12 you should be mid to upper 600's at a minimum. Did you do a datalog while on the dyno or did you do all remote tuning.? And yes I am a firm believer that the intake change did eliminate the flatline.

Hit 10psi on a mechanical Roush gauge. One pull he went up to 7500 and it hit 11psi. Boost is just a measure of restriction, for example, not sure about your exhaust but my setup is catted and I have the stock resonator in the middle.

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[whatsup62]

Hit 10psi on a mechanical Roush gauge. One pull he went up to 7500 and it hit 11psi. Boost is just a measure of restriction, for example, not sure about your exhaust but my setup is catted and I have the stock resonator in the middle.

Yeah Im uncatted Kooks longtubes no resinator 3" all the way back. Timing is right where i was on 93 17.5 - 19

 

[mustang_guy]

Isn't the boost box not accurate though? Ive seen a few people here say it reads a few Psi low

 

[SolarFlare]

Isn't the boost box not accurate though? Ive seen a few people here say it reads a few Psi low

We'll see. I told him dyno operator and I both saw the boost climb no problem. He wants to be able to see it so I'll give it a shot. I'll also give the ol' resonator delete a shot. It's only 2.25" just before it, that's just silly.

 

[3beeps]

Isn't the boost box not accurate though? Ive seen a few people here say it reads a few Psi low

That wouldn't really make sense if it read a few PSI too low. Mine shows almost 13 PSI at ~7500 RPM with a 4.88 pulley and a D1SC. If it was reading low, I'd be at 15 PSI on the biggest pulley I can fit. AND I have headers so that should drop the boost a tiny bit.

 

[mustang_guy]

That wouldn't really make sense if it read a few PSI too low. Mine shows almost 13 PSI at ~7500 RPM with a 4.88 pulley and a D1SC. If it was reading low, I'd be at 15 PSI on the biggest pulley I can fit. AND I have headers so that should drop the boost a tiny bit.

Maybe. I just know people said it was definitely off. :shrug:

 

[SolarFlare]

I'll know for sure soon enough. I trust my mechanical gauge way more than a box.

 

[donmcgowen]

That wouldn't really make sense if it read a few PSI too low. Mine shows almost 13 PSI at ~7500 RPM with a 4.88 pulley and a D1SC. If it was reading low, I'd be at 15 PSI on the biggest pulley I can fit. AND I have headers so that should drop the boost a tiny bit.

What altitude are you at? I have a D1 with the 4.88 and seeing only 10psi on my built in boost gauge on a 15 GT. I know it's not perfectly accurate but I was hoping to see at least 12psi. I'm thinking of going with a smaller pulley.

 

[SolarFlare]

What altitude are you at? I have a D1 with the 4.88 and seeing only 10psi on my built in boost gauge on a 15 GT. I know it's not perfectly accurate but I was hoping to see at least 12psi. I'm thinking of going with a smaller pulley.

My stock gauge is on point, but I doubt it's the same for all setups.

 

[smokinzx14r]

We'll see. I told him dyno operator and I both saw the boost climb no problem. He wants to be able to see it so I'll give it a shot. I'll also give the ol' resonator delete a shot. It's only 2.25" just before it, that's just silly.

I really don't think the stock exhaust is holding you back .. Before I burnt my stock Cats up mine ran great with stock exhaust .. Yes the cat deletes helped a tiny bit but the rest of my exhaust is still stock and I have no flat spot at 6500 .. Mine is on a up hill line up to my 7300 shift point ..I'm still on the stock intake manifold with all the Vacuum lines hooked up just as procharger wanted them ..I know that you have been over every part of you car looking for the problem and found nothing .. So what is left ? It has to be in the tune ..

 

[3beeps]

What altitude are you at? I have a D1 with the 4.88 and seeing only 10psi on my built in boost gauge on a 15 GT. I know it's not perfectly accurate but I was hoping to see at least 12psi. I'm thinking of going with a smaller pulley.

I dyno'd at 1100'. The nGauge shows 11 PSI on the dyno in 5th but on the street I see 13 PSI in 3rd (both at 7500 RPM). That's with the stock intake manifold.

 

[dubster99]

I've seen multiple people with the boost box and inaccurate boost readings.

 

[SolarFlare]

I really don't think the stock exhaust is holding you back .. Before I burnt my stock Cats up mine ran great with stock exhaust .. Yes the cat deletes helped a tiny bit but the rest of my exhaust is still stock and I have no flat spot at 6500 .. Mine is on a up hill line up to my 7300 shift point ..I'm still on the stock intake manifold with all the Vacuum lines hooked up just as procharger wanted them ..I know that you have been over every part of you car looking for the problem and found nothing .. So what is left ? It has to be in the tune ..

Im currently on Longtubes with high flow cats, stock resonator and magnaflow 5x9s outback. I didnt think the resonator would be so restrictive. I figured most would be gained from removing stock headers and cats. Blower was installed by Mak Performance, I trust those guys, theyve done tons of these setups including their own car, I'd believe in bigfoot before believing something they did was wrong.

 

[Tommy V]

Maybe. I just know people said it was definitely off. :shrug:

Your correct when the came out they were not accurate.After a bunch of complaints,lund did a software update and supposedly they are pretty accurate now.

 

[SolarFlare]

To those with logs available, I need a favor, can you all tell me what your lbs of air flow is and where it peaks?? I see around ~70lbs at 7000 and a max of 78lbs at 7800 rpm. Please state if you have a P1 or D1 and if it's stock manifold and headers. Thanks

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