Going over the max impeller speed on a Vortech V-1 SC-Trim?

[TireSmoke]

Vortech Impeller Speed says 50000

8" renegade pulley, 3.3" blower pulley, 6200rpm max rpm = 51854.55 impeller speed

If I wanted to run this setup on my 87....I guess I don't plan on seeing 6200 rpm often, but with 3.90 gears its possible that I'd get up there on the top end.  1800 over the max impeller speed ok or would I be blowing the thing up?

[TireSmoke]

Well it looks likle the Efficient Max speed is 45,000rpm....so much above that I'd just be blowing hot air?

[Brian 00GT]

I think that after that Efficient Max Speed it just stops pushing more boost, but I am not exactly sure on that.  I am sure that at some rpm it will detonate the blower, though.  How much boost is it pushing out now?

[TireSmoke]

0psi...

just figuring out a blower for an install with my existing setup this spring

302, GT40Ps, F303 cam, 8.5:1 compression, full exhaust, BEGGING FOR BOOST

[Brian 00GT]

If I were you, I would just go with a T-Trim.  Why top out an S-Trim and then have to buy another blower or get that one upgraded?  Besides, I love the way my T-Trim sounds.  It sounds like I have a cat caught in the fan at idle and is extremely loud at 5k rpms lol.    Just my .02

[TireSmoke]

$$$....and I dont need to venture into bottom end break land.... I figure i can get 375-400rwhp outta the V1-SC and it'll run like a madman for a street car....

[Brian 00GT]

If all you are looking for is 375-400, then the V1-SC is the way to go.  It should do that without a problem as far as what I have seen.

[speedfreak87]

$$$....and I dont need to venture into bottom end break land.... I figure i can get 375-400rwhp outta the V1-SC and it'll run like a madman for a street car....

if you'r gonna go, go big... p****...

[TireSmoke]

STFU Mr. 210rwhp or whatever...LOL...

[sinister88lx]

How much boost are you looking to run?An s-trim is good for about 17psi

[Brian 00GT]

How much boost are you looking to run?An s-trim is good for about 17psi

I always thought that they were only good for a true 14psi or so   I may be wrong.

[Dan]

My friend couldn't push more than 12 out of his, but he said it should make 14 max ideally.

[sinister88lx]

Depends on the combo.My s-trim started out at 10psi.Better heads,stroker short block and some other choice parts and now I get 7psi.And thats with a power pipe.The better the motor flows, the lower the pressure will be.CFM is still the same its just not backing up inside the motor.

[Brian 00GT]

Depends on the combo.My s-trim started out at 10psi.Better heads,stroker short block and some other choice parts and now I get 7psi.And thats with a power pipe.The better the motor flows, the lower the pressure will be.CFM is still the same its just not backing up inside the motor.

So doesn't that confirm that an s-trim tops out fairly low   And I would assume that you haven't seen a loss in the added power of the s/c? 

[sinister88lx]

I have never changed the pulley.Once I get my new injectors,I will try a new pulley.

[Brian 00GT]

I have never changed the pulley.Once I get my new injectors,I will try a new pulley.

Which pulley is on there now?

[sinister88lx]

Its the factory one.I believe its 3.33 inch

[cmccarthy]

You can spin it about 20% above max, but efficiency will be in the crapper. Unless you're running a gigantic aftercooler you're wasting horsepower. Max efficiency isn't the max boost, but the point at which heat soak will kill any additional HP gains. It will pretty much continue to gain boost until the impeller fails.

Also, the better the heads/intake/exhaust flow and/or the greater the engine displacement, the lower the boost number will be. Boost is a measurement of backpressure in the intake side of the motor, nothing else. This is why an S-trim at 50,000 might make 25psi on a stock 302, and only 10psi on a yates headed 408. It's flowing exactly the same amount of air in both applications, but the big motor is using much more of it, so less air is stacking up in the intake.

Furthermore, removing restriction on the inlet side of the blower will increase boost because it increases the amount of air compressed with each revolution of the impeller. This is how/why "powerpipes" work.

[sinister88lx]

Thats what Ive been saying.The more mods i did,the less boost I saw even though I was making more power.Unlike my turbo car where boost is a constant regardless of my mods.The s-trim is just about at its peak at 17psi.I know guys who are running 19psi but they need all kinds of fuel to keep the death rattle away.I believe MM&FF did a test on an s-trim a while back and found that after 20 it was just superheating the air.

[cmccarthy]

Again, boost and impeller speed aren't directly relative, but charge temp and impeller speed are. On a 460" engine, the boost may only be 10psi at 55,000 impeller speed, but the charge temp will be the same as a 289" engine with 25psi at that same impeller speed.

The reason the turbo boost stays the same regardless of mods is because your boost controller is set at "X" and it will simply continue to increase turbine speed until it obtains that boost number.

[sinister88lx]

When my turbo is set at 15psi,it will make 15 psi regardless of mods.The boost pressure is controlled by my wastegate.When the wastegate reaches the preset pressure it opens relieving the exhaust pressure and slowing the turbine down.Funny thing is the compressor wheel on my s-trim is the same shape as my ta49 turbo only a little larger(bot have 6 double blades).Yet my s-trim is done at less than 20psi, but my ta-49 is good for 25-27psi.Its all about the efficiency.

[TireSmoke]

well you gotta figure.... a blower is limited by how fast your engine can rev, and the pulley attached to it.  In most cases a turbo will spin WAY faster than a blower....

[Ralph]

By the way, guys, I work in a bearing shop and I can tell you that the rpm suggested has little to do with impellers coming apart rather than the rated speed for the bearing.

The small bearings they're running on there are rated at 50k...  However, we've run them at significantly higher, uncooled, nonstop for weeks on end to do endurance tests, and I can tell you that the bearings that vortech is using can withstand a lot more abuse than the rated max.  Also a company called wynjammer, we rated bearings for them as well.

[hrtatack1]

You can spin it about 20% above max, but efficiency will be in the crapper. Unless you're running a gigantic aftercooler you're wasting horsepower. Max efficiency isn't the max boost, but the point at which heat soak will kill any additional HP gains. It will pretty much continue to gain boost until the impeller fails.

Also, the better the heads/intake/exhaust flow and/or the greater the engine displacement, the lower the boost number will be. Boost is a measurement of backpressure in the intake side of the motor, nothing else. This is why an S-trim at 50,000 might make 25psi on a stock 302, and only 10psi on a yates headed 408. It's flowing exactly the same amount of air in both applications, but the big motor is using much more of it, so less air is stacking up in the intake.

Furthermore, removing restriction on the inlet side of the blower will increase boost because it increases the amount of air compressed with each revolution of the impeller. This is how/why "powerpipes" work.



very smart mr mccarthy...absolutely right


a powerpipe will solve your woes, and bring up your efficiency jd