Those of you with Vortech Si-Trims?-Boost? Pulley size?

[HandsomeRob]

id run a 2.85 with a 10%OD. Stock tensioner will be fine thats what i use with no issues.

The max speed of my impeller on my Si-Trim = 55,000.
If I do a 10% Overdrive and 2.85" pulley at 7000 rpms I will be spinning it at 61430. 10% Overdrive with a 3.125" is = 56028

I plan on doing stock cams with mid length headers and stage 3 port and polishing.

 

[stangnutlx]

your not going to hurt it with a 2.85 pulley. Sustained blower rpms is what will wipe them out, your not going to stay at 7grand for 20 minutes.

 

[Stanger00]

your not going to hurt it with a 2.85 pulley. Sustained blower rpms is what will wipe them out, your not going to stay at 7grand for 20 minutes.

You're right but the blower is out of its efficiency range with the impeller spinning past 55k.

 

[HandsomeRob]

im doing a 3.0" pulley and a 10% overdrive. That puts my blower rpm's at 58360 @ 7000 rpm. I'm happy with that. I'm going to shift at 6800 rpm anyways which puts the blower at 56695

 

[Deceptive]

I heard the Vortech V1 Si underrated by Vortech. I am unsure how true that is. Just word on the street.

How do you like your V1? I just bought one for my GT. I plan on a MMR Kit in my Teksid Block with .020 bore about 10:1 CR, Ported heads, custom blower cams from Bullet, and maybe a P51 Intake with a 3.1 Pulley

 

[HandsomeRob]

I like my V1. I had it rebuilt to an Si but haven't installed it yet.

I plan on also doing a MMR Kit in my Teksid Block with .020 bore about 9.5:1 CR, Ported heads, custom blower cams and a 3.1 Pulley with 10% overdrive crank

 

[2003GTIZZLE]

V1's are awesome. I have a million miles on mine, and cant tell you how many people have used it prior to me, never been rebuilt as far as I know. Car is making 440+ to the tires with a 3.33, I'd give the ol V1 a pat on the back for that.

I'd like to do the rebuild and SI upgrade, but I ask myself why? Car runs so good now and with the stock shortblock loving it so far, why change I guess.

JTR

 

[HandsomeRob]

Anybody else running a V1 Si Trim?

 

[Stanger00]

I do not think there is a difference between a V-1Si trim and V-2Si trim the impellers and volute and bearings should be the same.

 

[HandsomeRob]

The V2 Si and V1 Si are most definitely different.

 

[Stanger00]

Guess the gears are different in the V2. However, I have my V2 spinning over its max rpm but only seeing 16psi at 7k rpms. The 2 valve made ludicrous power for the power adder that I have. I'll be willing to bet that the V1 would of produced the same numbers as the V2 I run.

 

[Elnrownr]

The v2 has a higher step ratio it basically spoils harder than a V1 .

Sent from my EVO using Tapatalk 2

 

[Stanger00]

Looked it up.

V1 has 3.45 step up ratio.
V2 has 3.60 step up ratio.

Wonder if the engineers bothered to design a impeller for that step-up ratio? If not, I still do not see a difference in overall performance for the little V1 and V2 modular superchargers and max impeller speeds. Looks as though I'm over spinning mine buy a lot but without knowing the equation for slip I will consider my car safe.

Current state with V2 Si trim (52k max impeller speed) 3.1" pulley and 10% overdrive crank being spun up to 7k engine rpms.