vortech v1 boost questions

[mystickb1996]

im wondering if someone can tell me if this sounds right, i have a fully built 96 cobra with 10.1/1 cr aluminator and a vortech v1 with meth and a 2.90 pulley.. i haven't really drove the car much since i put on smaller pulley, i switched from a 3.33 which was seeing 9 psi max. so my question is the car just doesn't seem to be making boost like it should. with the 2.90 its seeing maybe 10-11 psi max from what iv seen. and thats ringing it out to 6800. i can tell ya right now im missing my twin screw!! theres no intercooler on the car so im not loosing it through that.

please let me no if this sounds right also the car doesnt even see 1-2 psi till prob around 4500 or so

 

[MOTOWN M]

Something is definetly not right! you should be seeing twice that amount of boost.

What size is the Balancer stock, or aftermarket? are you running a bov/bpv?

 

[96snake719]

when I was running my V1 I was only seeing 11 psi max, and that was with a 2.87 inch pulley... I was making 588 rwh though so I wasn't to concerned about it lol

 

[Brutal Metal]

I just had an issue with stock damper failing and I just noticed today that I
was down 5lbs of wot boost,the cause? Tensioner is shot it moves freely
just by pulling the belt. My guess you have belt slip with a 2.9 6rib. You should
be about 16lbs with that pulley

 

[01yellercobra]

Did you need a new belt with the new pulley?

 

[mystickb1996]

stock balancer, and wouldn't i notice belt slip? i mean on my twin screw i def noticed when the belt slipped. and no i didnt replace belt as it was tight and with new pulley its about half way up on tensionor.
and the car made 485whp on the 3.33 pulley, but honestly it really doesnt pull like i thought it would and this is even more boost then the 3.33 so car is prob making 530+ maybe more
also my timing is only 12-13 degrees which im wondering if thats why it feels so doggy up high.. idk im just lost and ready to put a different setup on this.

 

[Brutal Metal]

Again I think its a belt slip issue.with that small 2.9 on
a 6 rib the tensioner needs to really do its job under a 3" head unit

 

[mystickb1996]

but you dont hear the belt slipping? or any signs other then the low boost number? just seems like it would be loud when it slips..and what do you mean needs to do its job under a 3in head unit? you referring to the v1?
thanks for the help

 

[01yellercobra]

You don't have to hear it to have belt slip. I've always been told 3" and under pullies need an 8 rib set up. When I had the D1 I tried a 3.4" pulley and the belt was too big. My boost went from 14psi to 5psi. Never heard a thing. Just had lots of belt dust and low boost.

 

[mystickb1996]

Alright I will check for belt dust and maybe throw on a new belt to see if it helps any.. I'm wondering if I have a vacume leak somewhere... I have a boost gauge but it does not read vac..

 

[Boston_Comic]

When I was curious about belt slip, I got a white laundry type marker that will write on anything. I used it to draw a line across the belt and on the s/c pulley. Also did it on the alternator pulley. It's not an exact science but when I checked it after a hard pull, there were nowhere near lined up. This may not be an exact diagnosis tool but from what I've read, with most s/c setup's there's some belt slip. I think it's bad when the belt basically spins faster on the s/c pulley than the pulley wants to spin. That's probably where the dust shows up. Since I've replaced my idler pulley and went to a good, Made in America 115" belt, my white marks usually stay close to where I originally lined them up. And I make 10 lbs. on a hard, high RPM pull. And I'm running a 10 year old V1 on my 1998 Cobra.

 

[mystickb1996]

any ideas on 10 psi on a 2.90 pulley? belt slip in not an issue i dont have any dust from the belt. has anyone seen these blowers going bad and not making boost? im lost. i also considered the bypass being bad but i unhooked it and did a run and still only 10 psi and its slow to get there.

 

[01yellercobra]

any ideas on 10 psi on a 2.90 pulley? belt slip in not an issue i dont have any dust from the belt. has anyone seen these blowers going bad and not making boost? im lost. i also considered the bypass being bad but i unhooked it and did a run and still only 10 psi and its slow to get there.

Check your boost gauge. I thought mine wasn't making boost until I checked the gauge. I adjusted my air compressor down to 20psi and the gauge only showed 10psi.

 

[19935.slow]

Centri blowers don't make any sounds at wot like a twinscrew dude. You might hear it sound like it's nosing over, but there is no other noises to listen for when the belt slips.

 

[98 Saleen Cobra]

Hey man,

per our convo today, check the bypass valve, I'll bet it's being pushed open under boost, bleeding boost..

Also I'm rather shocked you don't have belt slip with the 2.9.. I would look into a 8 rib if you go smaller..

The stock tensioners are shit.. I put a thump on mine after throwing belts every 300miless.. I haven't thrown a belt in 6k miles now..

You should be seeing 16ish psi like I told you today. I didn't realize that the timing was so low on your setup too..

If you have any question bro you have my number just hit me up

 

[mystickb1996]

thanks man! you defiantly helped me out today and sounds like this is a pretty easy fix, also being that i have another bypass valve laying around. and yes the car is vary detuned, wot timing is lucky to see 13* and thats with iat's around 90-100 spraying meth... im gunna put the new valve on and get this thing tuned again and she what it does...hoping for 550+ with a good tune.. about the belt slip, im not really sure, i have no dust or signs of it slipping and when i had the 3.33 pulley on the car it was low on boost also for what a 3.33 should produce

 

[98 Saleen Cobra]

Interesting.. Well keep me posted bro

 

[SVTPete83]

It will also depend on the year that v1 was made. I have an older v1 with the straifht cut gears. Its the loud version. Its maxed out at 13-14 psi and 520 rwhp. That is with a 10% overdriven crank and a 3.33. You bypass is probably leaking boost like Chris said. I would also recommend a thumper and an 8 rib as well.

 

[blownstang4.6]

Definitely check bypass and for any vacuum leaks. My V1 S was built in 06. Non-intercooled with 3.6 pulley and powerpipe it was hitting 9psi at 6,000 rpm. Right now it hits the same 9psi with a 3.33 pulley, procharger 3 core intercooler, and powerpipe. I'm thinking of throwing a 3.12 pulley on it soon to get it up to ~ 10.5psi at 6k rpm. If you are revving it to 6800rpm then it should definitely be making more boost. I don't think I've seen a V1 S make more than 16psi.

 

[mystickb1996]

yeah its an older v1 with the strait cut gears (the louder one) are you saying these dont produce as much boost as the newer ones? i should have the new bypass on by this weekend im just trying to find someone to weld a flange on for me.. blownstang you know anyone in the chicago area that can weld something like this up? im new to the city, i see your from chitown