Something I wish I knew about the 2.3 tvs

[Benz_tech]

I just tried dyno tuning my 2.6 pulley tvs blower with 21 psi and the boost would
Drop from 21 psi to 12 at 5200 rpms, with no belt slip (tight belt with thumper tensioner).


we called VMP and they told us the blower can't go below a 3.0 pulley on a stock motor.
It will begin to bleed boost internally. 2.8 and lower pullies require cams. I tried and I am very
Bummed that I never heard about that until now because I'm left
With a blower that I can barely get over 600 hp with a 3.0 pulley. How did you guys get it to work? I have
Stock headers. I've read many times before of other stock motor guys pulling it off but
i can't for some reason.

 

[cj428mach]

Some one told you wrong. Lots of people on stock long blocks running 21+ psi with that blower.

 

[ttk53]

I have 3.2 upper 4# lower make ~19 psi and hold to redline makes 656 whp but I have long tubes

 

[Benz_tech]

That's what I thought! But for some reason mine just can't hang
But why?

 

[Blackedout]

What fuel ??? Plugs and gap ???

 

[Benz_tech]

E85 brf7e at .024

 

[timspony]

3.0 x 4# lower....21.7 psi - stock block and E85 here

 

[racerbox77]

My buddies 03 makes close to 7 with a TVS. He swears by them.

 

[xxjaymanzxx]

Something else is up I had a stock motor with tvs and 2.8 upper no issues

 

[Blueline]

I dont know, I have a 2.8 pulley and stock lower with a stock motor, stock headers. Im guessing 18-19lbs. and hoping no issues :shrug: My tuner rec. the TVS and I have never heard of them bleeding off boost on a stock motor.

 

[Benz_tech]

Ok well the guy on the phone may have been blowing smoke in my ass or not. So if it's not bleeding internally to you
Guys then it must be belt slip. I have the thumper on it, what else did you guys do to stop belt slip?!

 

[Blackedout]

What is your fuel system.... return/returnless.... what injectors ??? Pumps ???any dyno graph ???

 

[gabe1530]

do you have a boost/vacuum gauge? worth a shot looking for a boost leak.

 

[TRBO VNM]

E85 brf7e at .024

Wow, there is something going on. No way with e85 are you only making that power. I haven't seen less than 650 with e85 and the TVS. Now, that said, they all had long tubes, but they were also all 18-19#.

A buddy had a similar issue and it turned out being the bypass valve was bad and bleeding off boost up top like this. I bet that is your culprit if everything else is good.

 

[Benz_tech]

Boost bypass valve was monitored during wot on the dyno and it stays put.
I have fore level 2 return, id1000's, dual 465, 8an feed and return. Again just a fat boost drop
I'm going to be keep looking at ways to fix this belt slip.

 

[MalcolmV8]

Take your pulley off and take it to the machine shop. Have them put slits in it like Billetflow does. It'll bite into the belt hard and you'll have zero belt slip.

EDIT: although dropping from 21 PSI to 12 PSI seems like something other than belt slip.

 

[Benz_tech]

So what's everyone's belt, tensioner combo or anything else
To help reduce slip with these blowers?

 

[svtshadow]

Two things:
a)Bad Blower
b)Motor on its way to quitting

The last time my blower was dropping lots of boost in the high RPMs turned out that my rings were going bad... Btw, lots of people pushing 21+psi on stock motors.

GL

 

[Wicked46]

Something isn't right. I used a 2.6 upper back in the day with a stock lower, stock manifolds and accufab TB. VMP tuned the car and i made 647HP on race gas and 608 on 93 octane.

 

[Vr4me]

The belt could be too tight. It will hit the stopper on the tensioner and the boost will drop. I would check the belt chart and see how much smaller your belt is compared to the recommended size. You could also rev the car and watch it hit.