rr06rs said:

So what 66mm wheel are you guys using? The Pure Turbo pieces?

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No they are KTS wheels. They are the only billet wheels worth buying. All the other billet wheel companies care about is making a wheel that they can call "billet", because people will buy it. KTS started with making billet wheels but now offers extended tip versions, light weight blades, curved blades, anything you want they will build. Interestingly enough, they didn't know we wanted this stuff, they just came up with it themselves, how would we know we would have wanted this if they didn't offer it. They even offer tdo4 compressor wheels in 20t and 20t upgrade which is a 50mm wheel. Im getting a little off subject, but basically they make wheels they didnt exist prior to KTS's existence.

Boostdriven said:

I believe that 56mm wheel is 83mm on the exducer but even then should have no problem keeping 30 psi.

What exhaust housing u have and what is your red line? What size exhaust do you have?

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Im just going by whats posted on the holset discussion thread in the beginning about the different wheel sizes, I only measured my inducer. I totally agree that the car should have no problem holding 30psi, just not sure what is going on!

Car has a BEP T3 70A/R exhaust housing and I run 3" exhaust but it comes right out of the bumper so its super short.

Boostdriven said:

I believe that 56mm wheel is 83mm on the exducer but even then should have no problem keeping 30 psi.

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Nope- they're a 56/86mm 6-blade. Definitely have no problem making / holding boost:

http://www.dsmtuners.com/forums/152324214-post46.html

JusMX141 said:

Nope- they're a 56/86mm 6-blade. Definitely have no problem making / holding boost:

http://www.dsmtuners.com/forums/152324214-post46.html

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Well I'm glad you corrected me but do you have any ideas for the problem at hand?

doesitonall4rs said:

Im just going by whats posted on the holset discussion thread in the beginning about the different wheel sizes, I only measured my inducer. I totally agree that the car should have no problem holding 30psi, just not sure what is going on!

Car has a BEP T3 70A/R exhaust housing and I run 3" exhaust but it comes right out of the bumper so its super short.

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Well its hard to speculate on what it could be with out knowing what engine set up you have, what cams, what exhaust manifold?

Boostdriven said:

Well its hard to speculate on what it could be with out knowing what engine set up you have, what cams, what exhaust manifold?

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stock 2.0 engine with ARPs, DNP T3 Manifold, BC272s (on stock cam gears), JMF SMIM, still running a 2G MAF and an omni 4 bar in MAFclamp after 2500HZ.

doesitonall4rs said:

stock 2.0 engine with ARPs, DNP T3 Manifold, BC272s (on stock cam gears), JMF SMIM, still running a 2G MAF and an omni 4 bar in MAFclamp after 2500HZ.

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It's possible that your 2g MAF is causing a restriction for the turbo. I never ran that much boost when I had my MAF sensor so I can't say for sure. Another thing might be your cams. What is your vacuum at idle? If you have ecmlink v3 then your only a $30 dollar gm temp sensor away from converting to speed density, I would look in to that.

Boostdriven said:

It's possible that your 2g MAF is causing a restriction for the turbo. I never ran that much boost when I had my MAF sensor so I can't say for sure. Another thing might be your cams. What is your vacuum at idle? If you have ecmlink v3 then your only a $30 dollar gm temp sensor away from converting to speed density, I would look in to that.

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Both of these ideas crossed my mind! I am still running V2.5 however, it still would not be that expensive to upgrade to speed density. But I honestly think I will try another set of cams before I do that, really want to see how far I can push this MAF on the stock block! My vacuum at idle is around 15-10mmHg

doesitonall4rs said:

Both of these ideas crossed my mind! I am still running V2.5 however, it still would not be that expensive to upgrade to speed density. But I honestly think I will try another set of cams before I do that, really want to see how far I can push this MAF on the stock block! My vacuum at idle is around 15-10mmHg

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If let's say that MAF is causing a restriction before the turbo then cams will be just a waste of money unless eventually you switch to speed density. One other thing, when you did a boost leak test how high did you pressurized the system? Could it be that your blow off valve is not holding the boost, at lower rpms the turbo is able to keep up with boost but as rpms rise the engine consumes more boost so between that and leaky BOV you get a boost drop. This is just an idea to look in to, other then that I'm leaning towards the MAF issue or your 22psi wastegate spring just isn't enough to hold back the drive pressure.

The vacuum seems to be right for those cams, they are not bad cams, you should be able to to make good power with them to around 7800 rpms. I think your next upgrade sould be speed density, I switched my car over to SD and I will never go back to MAF.

Boostdriven said:

If let's say that MAF is causing a restriction before the turbo then cams will be just a waste of money unless eventually you switch to speed density. One other thing, when you did a boost leak test how high did you pressurized the system? Could it be that your blow off valve is not holding the boost, at lower rpms the turbo is able to keep up with boost but as rpms rise the engine consumes more boost so between that and leaky BOV you get a boost drop. This is just an idea to look in to, other then that I'm leaning towards the MAF issue or your 22psi wastegate spring just isn't enough to hold back the drive pressure.

The vacuum seems to be right for those cams, they are not bad cams, you should be able to to make good power with them to around 7800 rpms. I think your next upgrade sould be speed density, I switched my car over to SD and I will never go back to MAF.

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When I boost leak test I test to the boost I am running (30-35psi) I actually was having a problem with the FORGE BOV leaking at the seat for the valve. Which caused me to switch to the Tial Ebay Knock BOV. It works great now! 35psi not a single bubble nothing! I have tried everything! When I pressure test now the system is so silent it just sounds like you filled up a air tank not a single peep, whistle, or bubble!

The maf could be the bottle neck I may have to look into switching to speed density, just a shame, I really didn't want to retune my car. It runs so damn good .

doesitonall4rs said:

The maf could be the bottle neck I may have to look into switching to speed density, just a shame, I really didn't want to retune my car. It runs so damn good .

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If you do your own tuning then switching to SD will be piece of cake for you, and if you need some help I'll be glad to help you set it up and give you some pointers on what to look for. Your other option would be to use a GM 3" MAF, I have like 3 of them sitting at my house. One of them I have couplers on for a 3" intercooler pipes. If you want to go that rout let me know and I can send it to you for $50 with couplers. You will need to buy MAF cable from ecmlink but this will still be cheaper then switching to v3 and SD and it should be less tuning to do as well.