Supercharger Upgrade SCI -> SI
 

Hey forum,

I run the TopGun V1 supercharger kit after going from the default SCI setup Stillen offered. According to Vortech, the V3 SCI flows 1050 cfm whearas SI is 1150.

I am trying to gain a bit of more "usable" power in the low to mid range and this is my last stop. Has anyone actually done some SCI -> SI trim upgrade and what was the experience like? Was it worth it?


thanks!

-NT

I haven't done it but I can tell you that it's a well worth it upgrade

I have done the upgrade, but my kit isn’t getting installed until end of the month, and I won’t have “before” experience with it.

Where did you get the upgrade done? Did you buy the SI blower or send your SCI in? How much was it?

appreciate the time,

-NT

I purchased a used Stillen kit with TopGun A2A upgrade and the blower was SCI. I sent the blower this March to Vortech and paid $402 to upgrade (return shipping was $80)

I've sent out for a build a couple years back... turn around was not too bad. How is it these days?

From UPS door to door, 20 days total.

Just talked with them on the phone this morning, they gave me a similar time frame with the current orders they have.

Anyone use the Impellar upgrades from Superchargerrebuilds.com? Specifically:

Mid range 16 tall Billet impeller Vortech – 7075
"Designed for better low to mid range response, with some expected loss of top end"

My goal is to get more useable power in low/mid range. Description sounds on point for what I am going for. Wonder how much "loss of top end" there is with the V3 on our platform.

Have you ever heard/dealt with Impellar upgrades from Superchargerrebuilds.com?

This one caught my eye:

Mid range 16 tall Billet impeller Vortech – 7075
"Designed for better low to mid range response, with some expected loss of top end"

I've heard of them but I don't know anything about their impeller upgrade. I can tell you that I sent my Si sc into 928 Motorsports (one of the most popular upgrade companies) and had their Super Vortech upgrade done which included a billet impeller that made the same claims. Since I had already had a previous dyno log with the Si impeller, I did a comparison with 928's billet impeller and I actually lost low/midrange power and to top it off, one of the vanes on the impeller broke off and got sucked into my intercooler. I'd avoid aftermarket impellers and go with the Vortech's Si impeller and I'm not a big fan of Vortech. Terrible customer/technical service

Good to know! I must admit, I'm on a stock HR block and I went 1 pulley size down (serp side) and running the S&G velocity screen. Should i be worried about the extra 100cfm on a stock block?

Apparently belt slippage is something I need to look into. I am running the TBATT idler tensior and the supplied Gates belt. I haven't done anything on the supercharge side. What is today's solution without going Cog?

Edit: Just went through some old posts. Are these still valid?

Is this K080220RPM the actual charger size small belt?

https://www.jegs.com/i/Gates/465/K080220RPM/10002/-1

https://vortechsuperchargers.com/pro...ant=7811182081

How did your wastegate experiment go? I only have 93 here and no e85. If this think is going to go past 13-14psi, maybe this is something i should look into. Seb will be tunning me as well

Fuel return arrived yesterday, so i'll be installing this with an aero 340 pump + rewire while the SI upgrade is being done.

You're on an HR block, not VHR.? If so, then I don't know what the HR block will hold. Good question for Seb

I wouldn't go cog on the supercharger side. "Z"en on the forum or he's @minized123456 on IG has a great tensioner set up for the supercharger side (see attached photo).

The wastegate set up worked perfectly but another good question for Seb if he thinks you'd need adjustable boost.

You may want to talk with Seb about your fuel pump and injector size too

Yes, this is my 07 Nismo... I don't think i'll touch a vortech on my 14 nismo. I've thrown too much money on this V3 setup to get it right. Too noisy and tacky. I'm in FI TT kit prices at this point ;-)

Hmmm... peeeerrrrrrrrty. I'll check it out. Charger is getting pulled out anyways

Yeah... the HR on 93 pump gas will only go for 12 psi safely. I just want to shift the power curve to the left. I don't see why a manual boost controller just set to 12psi shouldn't do it. But, there are some cool features on those Greddy Profecs... not sure if I actually would use them though.

Actually was his idea... I have been running 1050dx's on a walbro 255 without a return set up. These up coming changes will put me on the boarderline... so safety measures really.


Thanks for the time!

I highly recommend the FI tt's :tup:

I agree, a manual boost controller should be fine for your situation.

Seb's the man. I definitely do what he recommends

That's effectively what the Rotrex kit does, just spins the blower at full potential using a wastegate to limit the additional boost resulting in moving the entire boost curve left. The exact same thing can obviously be accomplished with a vortech kit as well. The SI would get you part of the way there but a TI trim blower would be more comparable to the Rotrex in terms of CFM.

I don't know how well the Ti trim works on an hr but it didn't work worth a sh!t on my vhr. It gained a ton of boost but lost power and torque. Had to go back to the Si volute and impeller to get the power back

Yeah...i saw that as well.

What size external wastegate did you end up with? I'm seeing anything from 38mm, 44, 46, 50, 60. Finding aluminum flanges seems to be a challenge as well. I'm trying to find something that is the same size as the 50mm Tial flange.

It was a 44mm. We tried a 60mm at first but it didn't work right. I guess there's an issue with dumping boost too quickly.

Haha... I ordered a 44 and a 60. will Cancel the 60mm.

Definitely cancel the 60

I had that thought about the wastegate dumping too much air with the 60mm and got the 44 just in case. Thanks again for the info!

Will report back.

You're welcome. Happy to help

Actually curious, when the wastegate opens up when boost is reached... does it get loud? I was annoyed with the 50mm Tial bypass valve and ended up putting a recirc + silencer.

Finally just found an aluminum flange for the 44 mm wastegate. What a pita. I went through 3 different sets of V band flanges... only to realize that the Tial wastegate needs a specific V -band style.

Automods.com ended up having it... i grabbed one from ebay:

https://www.ebay.com/itm/281725022922

apparently this is a popular honda mod for high end turbo drag cars. They use the wastegate for launching....

Nope, not loud at all

I actually just had this upgrade done recently….. finally hit 10lbs with a filter in 92 degree summer heat lol. I’m on V1 TopGunz kit. Previous only saw 8lbs with filter… so happy with the upgrades so far. I’m also on a 9LB pulley.

Midrange is a lot better! Hard to describe just easier to drive quicker into boost