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CO_SVT

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I have a Gen II Whipple 2.3 with 3.2 upper/ 4# lower, manifolds, bassani x with cats and stingers. My boost gauge is reading 23-24psi with this set-up and everything I have found says it should be more in the 19-21 psi range. My question, is my boost gauge wrong or am I making that much boost.
 

nol300

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What was the boost when you had it tuned? I would just datalog to see what it really is running.
 

Anabolic

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that seems like a crazy amount of boost for only the 4lb lower and like -.3" upper... hmmm, are you sure all you're catching al lyour mods?
 

MalcolmV8

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What exhaust setup are you running? Are the people you saw with 19~21 lbs of boost running long tubes and free flowing aftermarket exhausts possibly off road pipes? If you're running manifolds and a more restrictive exhaust compare to the people you're comparing against you will read higher numbers. As your motor flows more air and becomes less restrictive it will show a little less boost on your gauge but power will be up.
 

03Snake04

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No way you should be making those numbers in boost even with stock manifolds

What gauge are you using? .. and has it always read that amount even during tuning
 

CO_SVT

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that seems like a crazy amount of boost for only the 4lb lower and like -.3" upper... hmmm, are you sure all you're catching al lyour mods?

Yes, I listed all mods that increase power, or have any impact on boost.

What exhaust setup are you running? Are the people you saw with 19~21 lbs of boost running long tubes and free flowing aftermarket exhausts possibly off road pipes? If you're running manifolds and a more restrictive exhaust compare to the people you're comparing against you will read higher numbers. As your motor flows more air and becomes less restrictive it will show a little less boost on your gauge but power will be up.

As stated above, I have Manifolds, with Bassani catted X, and Borla Stingers. The people I reffered to all have similar setups to me in exhaust and pulleys, I know that longtubes etc will lower boost.

No way you should be making those numbers in boost even with stock manifolds

What gauge are you using? .. and has it always read that amount even during tuning

I know, this is why I am asking for help lol. I have an Autometer Lunar series gauge, and as for tuning, it never showed that much because it was tuned at a higher elevation, showed 18-20 psi there, now I am a lot closer to sea level but that shouldn't account for 4-5 psi increase.
 
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Anabolic

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is your gauge at 0 when the car is off? is uit mechanical?
what;'s the stock boost gauge looking like under load because that's mechanical
 
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UnleashedBeast

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I have a Gen II Whipple 2.3 with 3.2 upper/ 4# lower, manifolds, bassani x with cats and stingers. My boost gauge is reading 23-24psi with this set-up and everything I have found says it should be more in the 19-21 psi range. My question, is my boost gauge wrong or am I making that much boost.

Better check your cats. When you show more boost than your setup normally should, they may be doing this. This was my driver side 3" Magnaflow metallic spun cat.
70fb1fa4.jpg


666705e7.jpg


The passenger side was almost flawless, but you can see where it was beginning to collapse as well.
8302f1bf.jpg


d6dfa849.jpg


I gutted them, and boost came back down to normal.
1ac0824d.jpg
 
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Anabolic

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where are you receiving a reading of 24?... is it a mechanical aftermarket guage or electric with a sensor

it's possible to have a bad boost sensor from an electric sensor
or have an uncalibrated mechanical sensor that doesn't read "0" when the car's off...
let us know where you're reading 24psi. does it feel like 24psi?
 

Darko

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Better check your cats. When you show more boost than your setup normally should, they may be doing this. This was my driver side 3" Magnaflow metallic spun cat.
70fb1fa4.jpg


666705e7.jpg


The passenger side was almost flawless, but you can see where it was beginning to collapse as well.
8302f1bf.jpg


d6dfa849.jpg


I gutted them, and boost came back down to normal.
1ac0824d.jpg

Damn! Good thing you figured it out.
 

UnleashedBeast

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Damn! Good thing you figured it out.

I knew they had to be doing it. Since the car was just reassembled for the latest mods, I decided to drop the mid pipe and guts the cats. I wasn't surprised at all, as this is very common in GT500 world.

Even if the cats were perfect, they would have been gutted. The current power level doesn't support cats on a GT500 with the rear O2 sensors and cat over temp protection disabled.
 

MalcolmV8

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I knew they had to be doing it. Since the car was just reassembled for the latest mods, I decided to drop the mid pipe and guts the cats. I wasn't surprised at all, as this is very common in GT500 world.

Even if the cats were perfect, they would have been gutted. The current power level doesn't support cats on a GT500 with the rear O2 sensors and cat over temp protection disabled.

What power level are cats no longer an option? I noticed those were magnaflows, not even stock cats. Interesting. I'd not heard this before.
 

Rick James

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How are you reading this boost?? The stock 2 bar MAP sensor will only read up to 14.7lbs of boost, so unless you are running a 3 bar sensor, you won't read boost accurately above that. Also, you SHOULD be running 20+ lbs with that setup. I have a gen II whipple with the 3.2 upper only and I am making around 19lbs with it. Do the math.....
 
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UnleashedBeast

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What power level are cats no longer an option? I noticed those were magnaflows, not even stock cats. Interesting. I'd not heard this before.

On the GT500, when we cross over the 600-650 rwhp barrier, cats are on borrowed time. This is assuming the tuner has disabled cat over temp protection to keep the WOT air/fuel ratio consistent. The GT500 chews up cats for breakfast.
 

MalcolmV8

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On the GT500, when we cross over the 600-650 rwhp barrier, cats are on borrowed time. This is assuming the tuner has disabled cat over temp protection to keep the WOT air/fuel ratio consistent. The GT500 chews up cats for breakfast.

Oh wow. So is this specific to the GT500s? I don't have to worry about my 03 Cobra right? :) Although my bassani bullet cats are just barely cats lol.

I'll have to inform my buddy on the GT500 thing. He has an 2011 he bought brand new and it's still bone stock but he's been buying a bunch of stuff for it and he wants me to install it all in the next few weeks. I believe he said long tubes, full exhaust, wants his blower ported, pulley, TB, tune and I forget what else he has for me to put on. He said it'll put him in the 625 whp range which I guess means his cats (assuming he runs any) are on borrowed time.
So the GT500s actually have a temp sensor back there? when the cats start to get to hot it changes the A/F ratio to cool them? I guess richens it up?

Great info. Most people don't think to check cats when boost numbers change.
 

UnleashedBeast

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Tell your friend to not waste his money on aftermarket metallic high flow cats. Within 6 months, they will need to be changed out...and that's a huge waste of money. He better go off-road style. Wish I did, would have saved me $300.00

The GT500 is programed to protect the cats at WOT for emissions purpose. However, to make the car fast...you have to disable this protection. When you do, cats are on borrowed time.
 

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