Ess 625 low boost issue

[Patrón]

Originally Posted by craio11

Problem appears to have been resolved. making 7.0-7.1 psi. The pull in the upper rpm range only way I can explain is it feels like a new car. You can defiantly tell and feel the difference.

Also this has fixed and idle issue I never really noticed. The car use to to idle fairly low 450 ish and hunt a bit. Now its around 600-650 and does not hunt it also better vacuum at idle. I think I am going to throw a new set of plugs into the car as well. I found a few post where there was some benefit to this and im sure these are original with 100k on them.

Iyzmi: The clamps appear to have been removed by the previous installer. As to why I could not even begin to guess. Only thing I can think of is they had a similar issue not getting the boots to seat and wrecked the boots when they tried to tightened them down. Then bought new boots and did the same thing . If you are changing yours my advice would be to remember these are basically like a carb boot on a motorcycle. if you over tighten them they will distort and leak. Some moderation goes a long way here.

As for the clamps they replaced the one time use with hose clamps of varying sizes as well...... I am not a fan of how it is but there is not much I can do about it as I do not personally have the tool to put the crimp clamps on

congratulations. it's a good feeling to find the problem and restore power.

what is your vacuum at idle now?

[azndrunk74]

Originally Posted by craio11

Problem appears to have been resolved. making 7.0-7.1 psi. The pull in the upper rpm range only way I can explain is it feels like a new car. You can defiantly tell and feel the difference. Hopefully i can get back to the dyno before it snows.

Also this has fixed and idle issue I never really noticed. The car use to to idle fairly low 450 ish and hunt a bit. Now its around 600-650 and does not hunt it also better vacuum at idle. I think I am going to throw a new set of plugs into the car as well. I found a few post where there was great improvement from a plug change and i have no idea how old these are.

Iyzmi: The clamps appear to have been removed by the previous installer. As to why I could not even begin to guess. Only thing I can think of is they had a similar issue not getting the boots to seat and wrecked the boots when they tried to tightened them down. Then bought new boots and did the same thing . If you are changing yours my advice would be to remember these are basically like a carb boot on a motorcycle. if you over tighten them they will distort and leak. Some moderation goes a long way here.

As for the clamps they replaced the one time use with hose clamps of varying sizes as well...... I am not a fan of how it is but there is not much I can do about it as I do not personally have the tool to put the crimp clamps on

great to hear!! congrats and enjoy the restored power!! i'm sure it pulls like a beast now.

i'm about to order new clamps and boots in preparation for my ess 625 install. could you do me a huge favor and provide the part numbers?

[Iyzmi]

Originally Posted by azndrunk74

great to hear!! congrats and enjoy the restored power!! i'm sure it pulls like a beast now.

i'm about to order new clamps and boots in preparation for my ess 625 install. could you do me a huge favor and provide the part numbers?

Boots - 11617838287
Clamps - 11617838284

[azndrunk74]

Originally Posted by Iyzmi

Boots - 11617838287
Clamps - 11617838284

thank you sir.

[craio11]

Yeah this was driving me crazy there was so many issues was like pulling threads. Got to take the car a cruise with a few "super cars" and it hangs right there with most of them surprised a lot of people.

Vacuum at idle around 16 now+-1. The boots are cheap from bmw so if you have any question about yours i would replace them.

[Patrón]

Originally Posted by craio11

around 16 now+-1. The boots are cheap from bmw so if you have any question about yours i would replace them.

I think my boost is ok but my vacuum is typically in the 13s sometimes fluctuating into the high 12s and rarely into the 14s. my idle is =/- 600rpms (cold start delete).

[craio11]

its colder here now about low 40's and im at 1500 ft above sea level. But its been staying steadily in the mid to high 15's

[Patrón]

Originally Posted by craio11

its colder here now about low 40's and im at 1500 ft above sea level. But its been staying steadily in the mid to high 15's

Thank you.
I'm still in the 80s here but n the cooler mornings it's still reading -12 to -13. Sometimes fluctuating into -14s but I've never seen it in the 15s or 16s. I'm catless so perhaps that affects it.

[Maxf80M3]

I'm seeing the exact same variable boost readings,

on the dyno all we saw was 5.8 in forth.
1st and 2nd i can see spikes 7.1-7.8 sometimes but a majority of the time is hovers low 6 and its really pissing me off. I've rebuilt the bypass, now im changing the belt , hopefully problem solved.

The car made 560whp and 360 trq on the dyno jet. numbers look great but i know the boost is off because its different everytime I push it. SO ANNOYING !

[Patrón]

Originally Posted by Maxe93

I'm seeing the exact same variable boost readings,

on the dyno all we saw was 5.8 in forth.
1st and 2nd i can see spikes 7.1-7.8 sometimes but a majority of the time is hovers low 6 and its really pissing me off. I've rebuilt the bypass, now im changing the belt , hopefully problem solved.

The car made 560whp and 360 trq on the dyno jet. numbers look great but i know the boost is off because its different everytime I push it. SO ANNOYING !

The OP hunted down the velocity stack couplers were defective as well as the clamps. your manifold maybe lifting due to loose connections at the velocity stacks.
my car runs like the devil but the 12-13 idle vacuum has intrigued me since day 1.

[Maxf80M3]

Originally Posted by Patrón

The OP hunted down the velocity stack couplers were defective as well as the clamps. your manifold maybe lifting due to loose connections at the velocity stacks.
my car runs like the devil but the 12-13 idle vacuum has intrigued me since day 1.

I also noticed I have a slight delay if I press the throttle quickly .....Like a bog or hesitation. Never noticed it driving.

[longuyen88]

Originally Posted by Maxe93

I also noticed I have a slight delay if I press the throttle quickly .....Like a bog or hesitation. Never noticed it driving.

My VT-625 has the exact same problem of quick throttle, then a bog for hesitation. At first I thought it was TA's so I replaced both and problem is still present.

Are you going to replace the clamps and boots?

Keep me updated!

[craio11]

I would highly suggest looking at the boots it doesn't take much to mess one up. Also to add to this two things.

First I had called ess about this variable boost problem on the gauge. I was told that hooking the gauge up to the line you tap for the diverter valve can cause this. In my case who ever installed it made the bend also extremely tight off the iac. I regret not fixing this at the time. so i wonder if this is the real causes of that issue.

Second I ended up replacing the main pulley on the supercharger with a 3.6 pulley. I have not had one erratic boost number since.

[Patrón]

Originally Posted by craio11

I would highly suggest looking at the boots it doesn't take much to mess one up. Also to add to this two things.

First I had called ess about this variable boost problem on the gauge. I was told that hooking the gauge up to the line you tap for the diverter valve can cause this. In my case who ever installed it made the bend also extremely tight off the iac. I regret not fixing this at the time. so i wonder if this is the real causes of that issue.

Second I ended up replacing the main pulley on the supercharger with a 3.6 pulley. I have not had one erratic boost number since.

91.4mm is smaller than the old 94mm and newer, current 96.5mm pullies for the 625 kit.

[Maxf80M3]

Originally Posted by craio11

I would highly suggest looking at the boots it doesn't take much to mess one up. Also to add to this two things.

First I had called ess about this variable boost problem on the gauge. I was told that hooking the gauge up to the line you tap for the diverter valve can cause this. In my case who ever installed it made the bend also extremely tight off the iac. I regret not fixing this at the time. so i wonder if this is the real causes of that issue.

Second I ended up replacing the main pulley on the supercharger with a 3.6 pulley. I have not had one erratic boost number since.

What psi are you hitting with the 3.6 or 91mm pulley ? 6rib?

If my boots leaked I wouldn't hold psi and my dyno numbers would be lower. I think my problem is in my belt or bypass.

I'm starting off with a 6pk2115 which is 5mm shorter then my stock 625 belt. One tuner suggested another wheel or guide just under the charger pulley would allow for better wrap .

[craio11]

I think i would tend to agree. I also switched to that belt and replaced the tensioner as my car was higher miles. The tensioner is cheap and rule out that issue. The car sits about 8.1-8.2 for boost and im at about 1200' for elevation. The pulley is still a 6 rib as well. I would take the bypass apart especially if its the older style vortech and see if the blader has a hole and replace the oring

[Iyzmi]

Originally Posted by craio11

I think i would tend to agree. I also switched to that belt and replaced the tensioner as my car was higher miles. The tensioner is cheap and rule out that issue. The car sits about 8.1-8.2 for boost and im at about 1200' for elevation. The pulley is still a 6 rib as well. I would take the bypass apart especially if its the older style vortech and see if the blader has a hole and replace the oring

Where did you buy the oring? I don't see it on Vortech's website.

[craio11]

unfortunately i cant help you there. My work has a very large selection of orings i got mine from there. but i believe i read some people were getting them from home depot/lowes. just make sure its thick enough

[R_lara]

Originally Posted by Iyzmi

Where did you buy the oring? I don't see it on Vortech's website.

I would recommend to leave a dedicated Boost vacuum line to the bypass valve and tap directly into the manifold for a dedicated boost reading only downside is no more vacuum readings.

[eatsleepboost]

Just bumping this thread since it was helpful to me.

I had the same issue with my car. Installed a new 625 kit and was only boosting up to 5.5psi and it was steady. I removed the intake manifold and my rubber boots were distorted like the pictures on page 2. I ordered all new oem boots, upper clamps and lower clamps. Replaced them all and used the advice of an earlier post and only lightly torqued the upper clamps to the velocity stack.

Results are perfect. Car boosts to 7.2 every time at sea level. Excited to have all the power. Car pulls hard.

[derrick]

Another bump to this thread. Extremely helpful to me.

Painfully BMW raised the prices for these intake boot/couplers #11617838287

They're on average $32-$40 EACH now (instead of $4).

Fortunately was able to find some for the old price and fixed my boost leak. Thanks OP and everyone else.

[Scharbag]

Originally Posted by craio11

Yeah if your making the right amount of boost the dyno is just a tool to tell you if something is up. In my case I'm down about 100+ hp.

So I had some time to work with it tonight. My vaccume is now 14-15 from 11-12 not sure if this means anything fairly small change. There is also a right and wrong way to install the bladder. Unless spring can't hold back the manifold pressure under driving conditions the valve isn't leaking.

My random boost numbers are making me think my problem is belt slip even though the belt and tensioner are new. If i mash it in 2nd I can get 6.7 occasionally. The boost being all mechanical if it can make it once it should be able to do it all the time. If it was a boost leak it would be static and not fluctuate. The fact I can still only do 5.5 in 3rd and 4th leads me to belive the diverter leaking was a red harring.

I am dealing with random boost numbers too on my G1 system. Going to take my plenum off today and I think based on how my stacks are sitting a little proud that I may have fooked up the install.

I am having the same issues. Some times it struggles to make 4PSI, other times it will hit 8PSI. Like Jekyll and Hyde :|

Thanks for this thread, this is why I love these forums.