20psi with S trim?

Can the Vortech S trim handle 20psi of boost? I thought it was rated up to somewhere around there. I am getting a hell of a deal on a whole setup and plan on building a motor that can take this kind of boost. Let me know. Thanks, Jarred

Straight cut spur gear

Fits engines up to 680 horsepower

Maximum airflow: 1,000 CFM

Maximum boost pressure: 20 PSI

Maximum impeller speed: 50,000 RPM

Adiabatic efficiency: 72%

Available with straight or curved discharge and clockwise or counterclockwise rotation

I answered my own ?

Well, according to ATI, my old P600B would do 24# of boost. There's no way in hell that's possible in the real world. 15, maybe 18, but not 24.

There's a difference between the max boost the blower is capable of against high resistance and what it actually produces when hooked up to a running motor. Kind of like comparing the pressure a fuel pump makes when it is against a closed pipe ("dead headed" ) versus the pressure it produces when hooked up to a fuel system.

Not sure if I am making this clear, but the point is that the max presure for a given compressor is not an indication of how much boost it will make on a motor. The CFM rating is a better reflection of max boost. On a typical 383, an S-trim or comparable blower (P600) will max out at 12-15psi. On my combo, I got 13-14psi from an S-trim (1,000CFM). With the Procharger F1 (1,525CFM) I see up to 21psi.

Rich Krause

So you don't think with a big enought bottom pulley and small enough top pulley I can near the 20 pound mark? How close could I expect to to get the S trim. Thanks, Jarred

Originally posted by 30thCamaroZ
So you don't think with a big enought bottom pulley and small enough top pulley I can near the 20 pound mark? How close could I expect to to get the S trim. Thanks, Jarred

Depends on your motor. The larger the displacement and the better the head flow, the less boost (but the more hp) that you will see. It's airflow, not manifold pressure, that makes hp. Think about a 2L 4cyl with a 20psi blower and a 383 V-8 with 20psi. Which makes more hp?

Rich Krause

Originally posted by 30thCamaroZ
So you don't think with a big enought bottom pulley and small enough top pulley I can near the 20 pound mark? How close could I expect to to get the S trim. Thanks, Jarred

In a word: No.

I'm using Vortech's largest crank pulley (6.66") and smallest blower pulley (2.75") on the larger T-trim and am seeing around 13 - 14 psi boost.

ASP makes a 7.00"/2.5" combo that would do around 15 psi, again, with the larger T-trim.

Mike

Mike, do you think I even could if I stuck with stock heads and just went with a blower cam. I would just upgrade valves, springs, etc. and maybe do 1.6's. I just want to know the best way to make loads of boost. Thanks, Jarred

Also if I have a S trim could I just buy the T trim later and swap it out right into place? Thanks, Jarred

Originally posted by 30thCamaroZ
Mike, do you think I even could if I stuck with stock heads and just went with a blower cam. I would just upgrade valves, springs, etc. and maybe do 1.6's. I just want to know the best way to make loads of boost. Thanks, Jarred

Perhaps I didn't understand the goal, but I think I got it now. . .

You want a high number to show up on the boost guage, but you're not worried at all about the number that shows up on the Dyno or the ET/MPH at the drag strip, right?

That being the case, leave the stock heads, stock cam, stock exhaust, and remove all of the driver's side rocker arms from the engine. You will make in excess of 20 psi boost in that condition.

You see, what Rich tried explaining earlier is that the more air your engine flows, the less boost pressure you have, but the more power you will make. If you build a stroker, you will lose 1 psi boost, but make more hp. Same goes for ported heads, bigger cam, etc. . .

Why are you worried about the boost number when the power number is what really counts?

Also, in order to run 20 psi boost, you would need to lower the compression to around 8/1, install an all-forged rotating assembly/4 bolt mains, install an exotic fuel system, extensive programming or FAST/DFI computer, etc. . .

Originally posted by 30thCamaroZ
Also if I have a S trim could I just buy the T trim later and swap it out right into place?

Yes. The only difference is the T-trim has a 3.75" inlet versus the 3.5" inlet on the S-trim. You need a larger hose to connect the inlet piping.

Mike

No Mike I understand about how the higher the CFM and lower boost I will make more power. If that is right? I just wondered what it would take to make 20psi is all. I plan on doing a fully forged 355 with like 8.5:1 compression. I thought with a good blower cam I could expect some pretty decent amounts of boost but I am understand what you are saying too. I don't think I would be able to afford the heads for a while is all. Thanks, Jarred

If you do the following, you could get maybe 16 psi effectively with an S-trim:

- 8.5/1 all-forged 350

- stock heads/good valve job/cleanup work

- blower cam (doesn't add boost, BTW)

- headers/good exhaust

- S-trim with 6.66/2.75 pullies

- aftercooler (a MUST to keep it from breaking)

- twin in-tank 255 lph pumps, one triggered by a boost switch

- either a Versafueler and large, low-impedence injectors, or some 42 lb/hr injectors and a Superfueler (I'm selling one right now, BTW).

- MSD or Crane ignition amplifier

- extensive programming/dyno tuning

Mike

Originally posted by 30thCamaroZ
No Mike I understand about how the higher the CFM and lower boost I will make more power. If that is right? I just wondered what it would take to make 20psi is all. I plan on doing a fully forged 355 with like 8.5:1 compression. I thought with a good blower cam I could expect some pretty decent amounts of boost but I am understand what you are saying too. I don't think I would be able to afford the heads for a while is all. Thanks, Jarred

Like Mike said, you can make a big number with a relatively small blower if the motor doesn't breathe well. If you have stock heads and a relatively small cam, you may see 20psi. However, also as Mike said, you will need stout bottom end parts and a low CR if you plan to max out the blower, whatever the boost it finally makes.

Rich Krause

Originally posted by engineermike
If you do the following, you could get maybe 16 psi effectively with an S-trim:

- 8.5/1 all-forged 350 this was my plan Mike

- stock heads/good valve job/cleanup work also part of plan

- blower cam (doesn't add boost, BTW) I know just helps hold boost and won't bleed boost

- headers/good exhaust Already done

- S-trim with 6.66/2.75 pullies

- aftercooler (a MUST to keep it from breaking) I am looking into a custom FMI

- twin in-tank 255 lph pumps, one triggered by a boost switch Thanks for this info I will look into that

- either a Versafueler and large, low-impedence injectors, or some 42 lb/hr injectors and a Superfueler (I'm selling one right now, BTW). No dinero right now but I will keep it in mind

- MSD or Crane ignition amplifier My kit is coming with the Crane HI-6TR

- extensive programming/dyno tuning Am converting back to OBD1 tomorrow so we can tune it for free

Mike

Be prepared to spend alot of time with a Wide Band O2 sensor and some sort of scanner when programming.

Mike

I hear ya there. Luckily my buddy can tune it for free for me and I am just gonna rent the dyno for like an hour so we can get some tuning in. This will be a ways off like next summer. For now I am just gonna bolt up the S/C kit and go. I am only 17 so I figure I am doing alright with a blown LT1 and then major motor is in the works. I have to fund it all so it helps to have friends that can help me out bigtime. Later, Jarred

Ask rich how many hours of tunning does he have ;)

I have a bit over 100hours on mine though.. may where on a dyno but I gave up on the tunning on the dyno.

I just got my OBD1 comp in yesterday and it has a MTI sticker on it so I emailed the guy to see if it is already tuned or has been "untuned" I guess. I picked it up for $100 shipped so w/e. I will have a lot of tuning done before we take it to the dyno that way we can just really dial it in hopefully. Lata, Jarred

I still don't understand why 20# is so important. I can understand shooting for mid 9s or 600hp, whatever, but why 20# of boost? If you choke up the engine enough, you can see all kinds of crazy numbers on the boost gauge. However, I'll GUARANTEE that a stock head/cam LT1 w/ 20# of boost will be slower than a 350ci motor built for boost on only 10#. 20# on a S-trim (probably even a T-trim) will put it so far out of it's efficiency range that you'll hurt performance....if the pistons don't take a ****.

Originally posted by The Highlander
Ask rich how many hours of tunning does he have ;)

I have a bit over 100hours on mine though.. may where on a dyno but I gave up on the tunning on the dyno.

Each new config takes 20-30 dyno runs (usually a full weekend on the dyno including setup and various fixes while in progress) plus lots of fiddling on the street to get it right. This is NOT a plug-n-play kind of a deal.

My car has a total of over 200 dyno runs :eek:

Rich Krause

"My car has a total of over 200 dyno runs"

Man that's a lot of time on the dyno. Do you own one or have a friend with one or do you have to pay everytime? I was not saying I was trying to get 20psi on a completely stock motor. On my stock motor I am just going to run 6# which is what the kit comes as and then I am going to build a fully forged 355 that is 8.5:1 and go with a blower cam and stock heads for now. I was just wondering if I would be able to see 20# after the built motor goes in was all. Lata, Jarred

Mine has many.. but you tune on the dyno and you go leaner at the street..

Originally posted by 30thCamaroZ
"My car has a total of over 200 dyno runs"

Man that's a lot of time on the dyno. Do you own one or have a friend with one or do you have to pay everytime? I was not saying I was trying to get 20psi on a completely stock motor. On my stock motor I am just going to run 6# which is what the kit comes as and then I am going to build a fully forged 355 that is 8.5:1 and go with a blower cam and stock heads for now. I was just wondering if I would be able to see 20# after the built motor goes in was all. Lata, Jarred

I have a friend with a dyno and I "barter" some work for him with time on the dyno.

Rich Krause

If its big boost you're after.... go turbo. More expensive.... yes, but you can boost it to the moon (or until your motor takes the trip itself).

its the same thing as a supercharger... or you think that if you use an eclipse turbo it will boost to the moon?

Turbos aren't mechanically limited..... 1500* exhaust gases will spool that turbo to speeds far greater than that SC with pulleys and engine speed.

Typical SC impeller speed: 40-60,000rpm

Typical turbo speeds:100,000+rpm

You make the call

Who cares about the speed of the impeller... a turbo from a Eclipse will spool 100,000 rpms too... and do you think it will make 5psi on our engines???

A YS-trim spools 65000rpms

You make the call...

Originally posted by The Highlander
Who cares about the speed of the impeller... a turbo from a Eclipse will spool 100,000 rpms too... and do you think it will make 5psi on our engines???

A YS-trim spools 65000rpms

You make the call...

Ok, i'm not gonna get into a pissing match with you over this so stop with the sarcasm. SC and turbos are very different, believe what you want. Who cares about impeller speed?... impeller speed means potential when it comes to compressors. And also where in the rpm range it makes this speed is CRUCIAL. You match compressor size to turbine size to get the most out of your range of boost. You brought up the eclipse thing like you think i'm a ricer..... check the sig, been dealing with boosted engines for quite a few years, SC and turbo. In the big end the turbocharged ones went faster and made more power 9 times out of 10. I'm done with this matter.

Back to the original topic....

I wouldnt poke to much at the Eclipse community. There are 600hp cars running around with 2L motors. Not common, no, but it happens.

A YS-trim is good for 1500CFM at max speed, which most likely is set to 6500rpm or 6000rpm on your engine or whatever you shift at... Assuming a max RPM of 7000, at 3000rpm that sucker is pushing theoretically at most 800cfm...

Lets get logical here...

A $600 Mitsubishi EVO III 16g turbocharger, with a decent port job and proper setup is good for nearly 600cfm. Now if we can run this turbo on a 2L motor that's built for boost, and hit full boost by 3000rpm (and as much boost as the turbo is willing to make) with a standard dump header (as opposed to a more efficient tube setup) and 22psi of boost on this 2L motor without hitting the edge of the compressor map...

A pair of these, each pushed by 2.85L of force (most likely more CFM then a 4g63T straight as stock DSM heads/cams hold good vaccum and an all out 350 wont).. will probably hit full spool by 2200rpm at WORST. Now that'd be two turbos, now flowing a total of 1200CFM at 2200rpm...

Too small? Step up to a 750CFM ported 20g. It'll push out full boost on a 2L by 3500rpm at worst! So you're talking probably 1500CFM by 2400rpm with two of them on a 350...

It's not precise... but a pair of $800 turbos by the numbers will flow the same CFM as that YS-Trim, and certainly hit max boost faster. At 3000rpm on that engine the pair of 20g mitsubishi turbos are already pushing 1500CFM and then all the way to redline. At 3000rpm your YS Trim is pushing 800cfm... And dont forget...

Less parasitic loss ;)

A turbo will sure make more boost at low rpm than a comparable sized centrifugal. But that's due to how it's driven. Put the compressor side of a centrifugal and a turbo side by side and they are hard to tell apart. Turbo will have the same limitations as a centrifugal with regard to max boost on a given motor. If it can't flow enough to supply the motor, the boost will drop and the ultimate hp output (peak) will be limited by the amount of air it can flow.

A comparable size turbo will make more hp than a centrifugal because of the hp it takes to drive the latter, but not more boost. If a given turbo makes a max 20psi on a 2L, it sure won't make anywhere near that on a 5.7L V-8. And the V-8 with that little turbo may not have much more peak hp than the 2L. You need airflow to make hp.

Rich Krause

Precisely.. the thing is that I get a bit tired of people saying that turbos are limitless...

On a civic they tested a similar flowing supercharger to a turbocharger and it yielded that the supercharger needed only 7HP more to drive it than the turbo... turbos are not all gains..

Mike, W/ a 6.66 and a 2.75" you are seeing 13-14 psi w/ an AFR headed 383 ci.....I wonder why I am only seeing 11-12 psi w/ the exact same pulley combo on a stock headed 355 ci....I am running the cc 224/236. W/ my S-Trim and a 2.75" pulley I only saw around 9 psi. I have a 7" waiting to go on once I hit the dyno, I just think its a little weird that I am not seeing anymore boost than I am.
Thanks
Scott

Probably S-trim vs T-trim difference.. there are 200CFM difference between them

Thats what I have is a t-trim now...I sold my s-trim and bought a t-trim and with that pulley combo I am only making 11-12 psi...w/ my s-trim i saw around 9....Doesnt this sound a little low to you guys?
Scott

Originally posted by BOOST FED 95Z
Thats what I have is a t-trim now...I sold my s-trim and bought a t-trim and with that pulley combo I am only making 11-12 psi...w/ my s-trim i saw around 9....Doesnt this sound a little low to you guys?
Scott

Intake restriction? I saw a 2-3psi gain with the S-trim from replacing the "dryer hose" with a solid pipe. With the F1, running it without any intake piping gains 4-5psi.

Rich Krause

I do have a hard intake pipe, as well as a fully ported and bored MAF.

Something else to consider is that the Vortech bypass valve leaks over 10 psi. I replaced mine with a used Eclipse 2G unit, which is good to 15 psi.

Mike

Which bypass? the mondo? or the plastic one?

The plastic junk.

Not all of them leak, but INTMD8 picked up ~45 rwhp with his S-trim by replacing the Vortech bypass valve.

On the other hand, LJ has run 9.90 at 139 mph with the plastic Vortech bypass valve. . .

Mike

I think I will try both of those but first replace the bypass valve.....Do you recommend the mondo or the eclipse unit.
Scott

Eclipse 2G valve: $20 used (The DSM guys upgrade to the 1G valve because it will hold 20 psi).

Mondo: $240

You decide. . .

The Eclipse valve also has hose conections and is roughly the same size and shape as the Vortech so it can be adapted easily.

Mike

Mike, so there is not alot of fabrication to be done w/ the eclipse unit?
Scott

The Eclipse unit is very similar to the Vortech, but all hose connections (inlet, outlet, and vacuum) are all one size larger, so you have to play with different size hoses to make it fit.

Mike

You can make 20 psi thru a stock LT1 if you make the overall combo as inefficient as possible.

Realistically, if it's all about the boost numbers, I'd try to run new valve springs, straight 104 u/l, and pulley it for 15psi. I'm think you'd make about 550-600rwhp for about a summer.