3.48 Pulley - 10psi?

I've been attempting to chase down the cause of only making about 5 lbs on a 3.6 pulley. Replaced the worm clamps with T-Bolts and leak tested. I threw on a 3.48 pulley and dynoed it. It only put out 550whp at 5.6 psi. I just removed the Maxflo Bypass valve and installed a Tial 50MM Q BOV (-2 psi spring) took it for a test drive and made 10.7 psi. I made 3 runs, reset the boost gauge every time and it made 9.9 once and 10.7 twice.

I want to be a 12-13 PSI with my BOV. It seems like there is still an issue. Any advice?

Changed to BOV, leak tested, used fuel line hose for bov+gauge (source from large line behind TB), T-Bolts.

Has it ever made the boost it should have on any pulley you ran at any time? Or has it always been low? You should be seeing 14ish psi on the 3.48 pulley. I see 10ish on the 3.8. Are you sure belt tension is correct?

just curious have you tried reinstalling stock bov?

dubster99 said:

Has it ever made the boost it should have on any pulley you ran at any time? Or has it always been low? You should be seeing 14ish psi on the 3.48 pulley. I see 10ish on the 3.8. Are you sure belt tension is correct?

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It did. I was making 11.5-12 with my 3.6 pulley. I was out racing in Mexico and broke my DS bolts. I checked my boost and it was only making 5.8 lbs on my last run which broke my DS bolts. Replaced with 4" aluminum ds.

I bought a brand new Gates 061010HD (101 5/8) and moved the pulley to the 4th hole from the left. It doesn't appear to be slipping. When I put the belt on, it was pretty tight.

Whtvans550 said:

just curious have you tried reinstalling stock bov?

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I had the maxflo bypass on when the issue started but cut the flange off and welded the tial on.

Only thing I'd think it could be is boost leaking somewhere, but you pressure tested. Or the blower just isn't spinning fast enough to make the boost. Any odd noises from blower? Leaks? Assuming your motor is ok.

dubster99 said:

Only thing I'd think it could be is boost leaking somewhere, but you pressure tested. Or the blower just isn't spinning fast enough to make the boost. Any odd noises from blower? Leaks? Assuming your motor is ok.

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Motor feels great. Blower has had oil changed every 3500 miles. No leaks that I've noticed. I'll do another leak test tomorrow since I have the BOV on instead of the bypass.

What was weird.. when I tested the car today, it made 6lbs when I went WOT in a short distance then made 9.9 after that and 10.7 twice.

Unfortunately Lund wants $50 to review a log, even though I've spent plenty on money on tunes with them. I'm going to switch to Sai Li but i don't want the car to be an issue before tuning.

Jay159866 said:

Motor feels great. Blower has had oil changed every 3500 miles. No leaks that I've noticed. I'll do another leak test tomorrow since I have the BOV on instead of the bypass.

What was weird.. when I tested the car today, it made 6lbs when I went WOT in a short distance then made 9.9 after that and 10.7 twice.

Unfortunately Lund wants $50 to review a log, even though I've spent plenty on money on tunes with them. I'm going to switch to Sai Li but i don't want the car to be an issue before tuning.

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That's why I switched to PBD. They wanted $400 to switch to a return system tune. Post your log here....there are plenty of guys that either are tuners or tune their own setups that could help diagnose.

dubster99 said:

That's why I switched to PBD. They wanted $400 to switch to a return system tune. Post your log here....there are plenty of guys that either are tuners or tune their own setups that could help diagnose.

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I'll do a new one tomorrow morning then.. Didn't know people here would look at it.

damn they are charging to review logs now?

RockStang said:

damn they are charging to review logs now?

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If you're outside of the initial period, wouldn't surprise me.

RockStang said:

damn they are charging to review logs now?

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Sep 3rd, 2017
"Tuning revisions for minor modifications are free of charge up to three months after you’ve received your initial tune. The countdown starts from the time you receive the tune(s) which may be up to 7-10 business days following your order. Following that period, cost to renew for an additional three months of revisions is $50."

It wasn't like that before.. At least they didn't enforce it if it was in place. That's one of the reason's I went with Lund.. They know what they are doing and they offer support for their tune.

U need to check your engine vaccum at idle and see what it is.Warmed up it should be around 22.Also best way to check for leaks is find someone with a smoke machine.

You said you reset your boost gauge, do you have an electronic or mechanical gauge? Maybe there's a disconnect in the amount it's reading. It sounds a bit odd to have that much fluctuation, also, do you have an intercooled set up?

Cobo_pro said:

You said you reset your boost gauge, do you have an electronic or mechanical gauge? Maybe there's a disconnect in the amount it's reading. It sounds a bit odd to have that much fluctuation, also, do you have an intercooled set up?

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I would suspect the boost gauge as well unless it is down on power.