Vortech JT-B vs YSi

[Blown38]

I put a YSi-B on a car. It is pretty much a dog down low. A real high stall converter really woke it up. I'm guessing it makes 750-800 rwhp on E85 at 26lbs of boost. This is on a 4400lb Marauder. It has GT500 cams and the bowls cleaned up in the heads, pulleys are 2.75 blower and 18% crank max rev is 7k thru the EEC. And a 6" IC core really helped keep the temps down. Pretty mild build.

Here's a little video how the boost climbs. Shook the tires a little. Converter flashes about 4500.

 

[Deceptive]

From everything that I read the YSi-B begs to be spun hard. It looks to be that if you don’t spin it to its max then it does not produce good numbers.

I’m really leaning to the standard YSi as it seems like it comes on hard early and just freight trains to the limit. I was looking at the 15% OD IW Crank with a 2.85 high grip blower pulley. That would put me at 68000 or so RPM on the blower.


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[Deceptive]

Word from Vortech into the inquiry about more information on the JT-B which turned into Vortech asking my plans is that the YSi would suit my car better. Vortech stated that I would not really see any benefit of the JT-B. They said that on my setup the YSi would do everything the JT-B could do at a cheaper price.

I would what the benefit of the JT-B would be.

 

[Helomech74]

Neither, I'd run the Procharger F1A-94 , but I'm a little biased.

 

[milktasd2]

I think somebody should take one for the team and try the JT, JT-b, ysi, and ysi-b back to back.

 

[98 Saleen Cobra]

LOL if people want to all pitch in the money for them I'll gladly sacrifice my car. I already did the JT.. I honestly don't think the JT-B will benefit greatly on my car.. I want to try a YSI and YSI-B though..

 

[milktasd2]

I got a dollar

 

[98 Saleen Cobra]

Need more than that. But you can figure that if everyone bought a blower we needed we can all swap to best fit each other’s combos lol

 

[Deceptive]

I guess I just don’t understand what the JT-B is for.

If they had more information that may help. I was told the JT-B supports about 1650-1675cfm where the YSi supports 1600. Does the JT-B make power sooner than the YSi? Is it more efficient? The JT has a 75% Thermal Efficiency where the YSi and YSi-B has 78%.

I know the YSi-B needs to be spun real hard to make power. Will the JT-B come on sooner than a YSi or will it just hold on a bit longer?

I just don’t get the JT-B which is a bit frustrating in making a decision.


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[98 Saleen Cobra]

From what I’ve read JT-b holds power better instead of falling off

 

[Deceptive]

From what I’ve read JT-b holds power better instead of falling off

That is something I read. I wonder how much you have to be overspinning the blower for that to become a factor.

I plan on a 15% IW Crank (7.5” is what I have read to calculate it), shift at 7500, and blower pulley of 2.85” which gives me a blower speed of about 68000rpms.

If the Vortechs are underrated, then I cannot see a JT-B being any improvement over a YSi. Now, if you are overspinning by 5-10k maybe.


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[98 Saleen Cobra]

They don’t under rate the blowers. They just can be overspun without major issues. Where prochargers tend to blow out seals. If you’re spinning it that hard I wouldn’t mess with anything short of a ysi.

 

[Deceptive]

I always read the Vortechs were underrated.

If I remember correctly I checked dropping to a 3” blower pulley and blower speed was 64xxx which would be close to the JT-B’s rated max.

I feel like being slightly over is better than under.

Or maybe I am just dead wrong.


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[98 Saleen Cobra]

So it's more than just that. it's likely the blower can't keep up with what your engine wants for air. Like for mine for example. I peak at 6400rpm.. Doing the calculator my blower isn't at max RPM yet. but the power rolls over and stays the same for anothe 2000rpm without going up in boost .1psi lol. I make 860/750 at 6400 rpm at 16.4psi and literally won't go up to 16.5psi to save it's life.. Remember I run a Holley Dominator ECU and I can read everything down to a decimal place. The JT is rated at 1000hp which I'm pretty much at or above and my engine wants more air. As you can see in my dyno graph. Now since I'm not overspinning the blower it carry's the power nicely. Lets say that I was at max blower RPM at 6400 and the other 2k rpm I use was overspinning. On a std JT it would drop and not carry, where as the B is likely to carry it more flatline like mine does. This is why I need a YSI. Even though I'm not overspinning the JT, it can't keep up CFM wise to what my engine wants and needs. If I slap a YSI on this car the power keeps climbing for another 2000rpm I'll be close to 1000rwhp I bet. I might lose some down low which is ok. I don't need all that tq to begin with.

 

[Helomech74]

F series Prochargers can be overspun with little issue. It's the street blowers that don't like it much. I've always preferred the step ratio of the Prochargers over the Vortech blowers as I don't need to run a small head unit pulley to reach the rpm I need. The only issue I have with Procharger is that they don't post or share compressor maps with the public. It would make it easier to select the correct unit if I could see a compressor map.

 

[98 Saleen Cobra]

F series Prochargers can be overspun with little issue. It's the street blowers that don't like it much. I've always preferred the step ratio of the Prochargers over the Vortech blowers as I don't need to run a small head unit pulley to reach the rpm I need. The only issue I have with Procharger is that they don't post or share compressor maps with the public. It would make it easier to select the correct unit if I could see a compressor map.

Ahh ok that makes sense. Yea the F series is much much better than the street blowers that's for sure.. That's weird that they don't post the compressor maps. I wonder why they would do that.. Seems dumb imo. Let the customer decide what they need and want.

 

[Deceptive]

Read some more, some say the JT-B comes on quicker and will hold on a little longer than the YSi.

Beefcake’s back to back on the JT vs the JT-B looked good. I could run a 3” pulley and be a few hundred rpm under the JT-B max vs a 2.85” and be 2000 over on the YSi.

I think the PSR 01 Intake would flow a bit less than your intake.

More research.


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[98 Saleen Cobra]

That intake is going to restrict you.. I would be looking into a sullivan imo. Better air flow direction into cylinders so one cylinder won't be getting more air than another causing a leaner condition in that cylinder.

 

[Prddad12]

I’d be happy to give some one my Ysi head unit for a few dollars shy of 2200 to play with and experiment

 

[Deceptive]

I think the PSR should work well. NA SVT has a guy doing it for all his recommended builds.

The guy that had Kurgan tune his 01 made something like 602rwhp @8lbs with a YSI and a stock intake.

Mine is the revised 01 and I plan on it being worked over a bunch. If I make 800rwhp, I will be happy. Sure, I’d love to hit the 4 digit mark but it is not that important as it is still a fun street car build at its core.

However, I have time to decide or change my mind. I should be sending my TVS build’s engine to the shop soon.

Edited as I was wrong about some numbers.

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