black_c7

Hey guys i have a 2015 m7 z51 and just isntalled a 10rib conversion for the ysi, the car is having some issues at 5600 rpm as soon as it gets to 15 psi it drops to 6 psi and 9 psi,

what do u think is the issue? Tubing leaks? Tensioner not tightened? (The belt is very tight but maybe it stretches at high rpm) or what do u guys think?

robert miller

I wouldn't think it was belt slip on a 10 rib set up unless the tensioner is weak. Check all of your clamp's how many miles on the belt, does it have all the ribs in it with not being cracks in them.

black_c7

I didn't think its a belt slip but my tuner thought of it, belt is new (one day old), tried to tighten all the clamps i could but still had the same issue

schpenxel

What bracket/tensioner setup?

black_c7

aa new 10 rib conversion bracket, also aa billet tensioner

FYREANT

Who's kit? A&A? If so I would recommend calling Andy or Josh over at A&A. They can help you track it down..

black_c7

Any suggestions

robert miller

What BOV do you have just also could be that when it get to a level. To let all of the boost off to a level of what ever. Look at chging out the spring in it are ask Josh are Andy.. Are you could just keep it no more than 14.9 lbs of boost Just kidding man that would drive me crazy and plus very up set... Robert

C7&7

The fact that it makes 15 psi then just falls off makes me think it's the blowoff valve. Do you hear the car blowoff when boost drops? Can you put a go pro under the hood and monitor the blowoff valve and then go drive it?

Do you have a dashlogic or anything you can monitor fuel rail pressure when this happens?

black_c7

Hahaha definitely that drove me crazy now i have to get another tuning appointment, bov is good I think it something in the tensioner, I tightened it a little now it drops to 11 and 10, probably stretches at high rpms

black_c7

I couldn't hear anything the dyno room kind of small and all i can hear is the ysi spinning and the engine reving, fuel is good as the tuner said, just the boost leaking or belt slipping

C7&7

Ah very nice. Yea another guy here on the forum had a similar issue with his procharger tensioner. Sounds like you found it!

robert miller

Is this A/A new one man just put a long bar on it and rap it and is if it gives in the higher end of what would be the end of the run out are top end. It should be harder at the top end of the run out.

I have seen a BOV spring cause this, But if have done what you have said and now 10 to 11 psi it would have to be that. Do you also think that maybe the bolt is some how could be off in the hole that it goes into and maybe backing off on you with all that tq on it. But sounds like for sure you have gotten to it.

I was just trying to help with what I had seen over in the car with the c5 in the past... Robert

black_c7

It just was the pulley that i have the tighten the bolt with was all the way back and wasn't applying pressure on the belt,

robert miller

Man glad you got it big PITA to get to this point and crap like this stop's a man from having fun So what is it at now since you can let it hit.

black_c7

Much agreed, I didn't put it back to the dyno yet will keep it posted

robert miller

The dyno is only a number, I will take a good tune on a car being tuned on the street are track over the roller ever time. But will agree on a really high HP car unless you can do all the work on a out of place road the rollers is safer for sure.

I don't care about a number just looking for a good drive by the seat car, and how it performs from the street to WOT to I let off the right foot. Robert

officermartinez

This EXACT same issue happened to us when we swapped over from an ECS 1500 to a 2200 blower. The 2200 was supposed to be in the area of 21-23 psi. Right at the 15 mark, it would fall flat on it's face. Could NOT figure out what was going on. Ordered a new belt and believe me when I say there is a tightening sequence on the belt. BE SURE TO FOLLOW IT TO A "T" ...after a brief conversation with ECS, we did as we were instructed. Viola, 22 pounds of boost!

On a side note, we did have to upgrade from our "quiet" Tial Qr.

black_c7

same thing here, now I'm at 21 22 boost, but didn't need to change the bov since i already had the race port bov, the problem was a very easy and simple thing,

there was a bolt on the head unit hitting the tensioner so the tensioner couldn't move that why i had belt slip when hitting the 21 boost,

is your head unit maxed out ?

Dave01GT

What blower and what size pulleys are you using?