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Old 11-28-2020, 08:45 AM   #201
pcampbell
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Default Vortech supercharger for ~500whp? Si Too big?



Minor issue I just realized the tensioner wont really take a large pulley because the tensioner uses a 1/2 drive square hole to crank down on the belt. If I go larger on the pulley it will cover the square hole unless I go just a tiny tiny bit larger but the clearance is just about as little as I want already.
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Last edited by pcampbell; 11-28-2020 at 08:57 AM.
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Old 11-28-2020, 09:28 AM   #202
stevieturbo
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Make a new pivot bracket with the square or tension adjuster further away.

It's just a simple flat bracket. Bit of time with a grinder would have a new one cut out.
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Old 11-28-2020, 03:05 PM   #203
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Good idea, maybe I can put my plasma cutter to use. I can trace the old bracket and just move the square hole.
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Old 11-28-2020, 03:09 PM   #204
stevieturbo
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Obviously if DIY'ing, it doesn't need to be a square hole. Just weld a nut or bolt or something onto the new bracket to allow you to tension it.

But an angle grinder is just as handy, lots of mess to clean up with a plasma. Oddly I just used mine the other day for the first time in about 5 years...
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Old 11-29-2020, 10:43 AM   #205
pcampbell
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Default Vortech supercharger for ~500whp? Si Too big?

I was able to get pretty good tension just by putting my weight into the idler but not sure if its enough tension. Lots more tinkering to do.

Last edited by pcampbell; 11-29-2020 at 03:28 PM.
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Old 11-30-2020, 12:34 PM   #206
pcampbell
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I moved the bracket and put on the larger tensioner idler pulley to clear the radiator hose. Now the belt is still slipping with the tensioner maxed out. The belt tension is decent , but not huge. Although huge is not necessarily good.

Here's the bracket with the larger idler, positioned so it can swing completely up and out of the way to get the belt on really easily. R&R of belt is like a 60 second process so that is really nice.



I feel like I have some options here:

1) Try a shorter belt. 61.5 instead of 62.0. This will give me more tension with the tensioner maxed out. Cost $9. I'm not super convinced more tension is a great thing though...

2) Try a RPM (Aramid/Kevlar) belt - only comes in 61.5 or 63.0 - 63.0 is too loose. These are actually designed to run LESS tension and do not stretch. $60 or so.

3) Just go 10 rib. I'd really just need to replace 1 idler pulley and replace my passenger side fan because I'm already running 10 rib pulleys on the SC and on the crank. I think I could hold off on replacing the fan for a while since it is cold here now anyway. $60 for belt and pulley.

4) Gear down to a 3.12" supercharger pulley which would obviously draw out the boost to higher RPMs which is effectively less restriction. $109 for a new SC pulley.

I am sort of leaning towards #3 first then #4 if that doesn't work.
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Old 12-02-2020, 05:54 PM   #207
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10 rib parts coming. It was only $40 in a pulley and a belt, so I had to try it. If that doesn't work I can try an RPM (Aramid) Belt. Then if all else fails, I can gear down the SC. One day I will paint these brackets too.

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Old 12-02-2020, 06:21 PM   #208
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A good strong spring tensioner would still go a long way to resolving any slip issues.. Although more ribs is almost always a positive.
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Old 12-11-2020, 06:06 PM   #209
pcampbell
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I got it up & running on the 10 ribs, definitely an improvement but not there. The 10 rib belt is either so much stiffer or slightly smaller, I had to mount the ribbed idler higher up to get it to tighten.

I decided to give the next easier pulley (3.12) a try though. Vortech has one called a "tall offset" which Vortech themselves could not tell me what that meant technically, so I decided to order it up and see for myself.

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Old 12-11-2020, 06:25 PM   #210
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Wouldn't be convinced those slotted belts could offer more traction ?

Although I guess if the belt structure is less inclined to stretch, that aspect would help. Although really you should not be getting any slip with a 10 rib and relatively low power for what a 10 rib can drive.
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Old 12-11-2020, 07:24 PM   #211
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Yeah honestly the belt was for testing the required length more than anything, it was super cheap ($7). I think a straight ribbed belt would be better although the slots are supposed to be good for less than perfect pulley alignment and I'm not sure how perfect mine are. I will keep tinkering!
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Old 12-12-2020, 01:47 PM   #212
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Found this which is kind of interesting - Dyno of the LA Sleeves FA20 stroker with the same Vortech supercharger, also nearly identical pulley gearing that I'm about to switch to, obviously very different motor though but I don't think there is any closer comparison out there.

They are making 408whp @ 17.77psi and 6500rpm and about 440whp @ 7000rpm and ~20psi on e85.

https://www.lasleeve.com/assets/imag...0tK08gF0x4Xv3k

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Old 12-20-2020, 08:13 PM   #213
pcampbell
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Default Vortech supercharger for ~500whp? Si Too big?

I just ordered a Gates "RPM" belt which is supposed to be the best - very little stretch. I also am working on an additional brace to reduce the bracket flex.

Last edited by pcampbell; 12-21-2020 at 05:22 PM.
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Old 01-17-2021, 07:13 AM   #214
pcampbell
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Default Vortech supercharger for ~500whp? Si Too big?

Still waiting on Gates belt.

Looks to me like Im maxing out my Cobb 255 pump or right on the edge . A little surprised but looking at this chart, I probably need about 64 gph at 62psi and closer to 70 gph at 64psi. Right at the cross hairs of where it is on the edge for 62psi and definitely below it for 64psi.

What I am seeing is afr rising at the top end and not going down when I add more fuel. I had the same experience when I started off using an outback XT fuel pump but it took me a while to figure out the issue.

Ill probably just do a drop in 340 for now.

http://www.tanksinc.com/pdf/4_series...flow_chart.pdf
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Old 01-17-2021, 11:57 AM   #215
pcampbell
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Quote:
Originally Posted by pcampbell View Post
Found this which is kind of interesting - Dyno of the LA Sleeves FA20 stroker with the same Vortech supercharger, also nearly identical pulley gearing that I'm about to switch to, obviously very different motor though but I don't think there is any closer comparison out there.

They are making 408whp @ 17.77psi and 6500rpm and about 440whp @ 7000rpm and ~20psi on e85.

https://www.lasleeve.com/assets/imag...0tK08gF0x4Xv3k



Something interesting I noticed here. They gained nearly 100hp going from 5500rpm to 6500 rpm. I think their belt was slipping pretty badly after that ,I would have expected 500whp by 7500rpm.
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Old Yesterday, 07:07 PM   #216
pcampbell
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I put my Gates "RPM" belt on, on a cold day , promptly pegged my MAF sensor before my set redline even. This is a 3" Outer diameter MAF housing with an honeycomb air straightener.

Will the car drive OK if I swap to a 3.25" OD (76mm inner diameter) MAF housing? I do believe the air straightener helps out with drivability quite a bit but I dunno. Is this too big of a MAF housing?

The other thing question is will it be OK to use a 3.25" OD MAF housing, but reduce it down to 3" AFTER the MAF housing??? I don't think I have room to run 3.25" OD behind the MAF housing to the supercharger. It sounds like in theory I'd get about 19% more top end reading with the 76mm ID housing... so that would get me to around 475 whp perhaps?

fwiw It looks like the Perrin BIG MAF does reduce diameter right after the maf housing.

Last edited by pcampbell; Yesterday at 07:45 PM.
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Old Today, 07:51 AM   #217
pcampbell
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2005 2.5 SC OB

Default Vortech supercharger for ~500whp? Si Too big?

Is a blow through MAF something I should consider?
I dont really understand the advantage other than I can do a BOV instead of a BPV.

A fancy PMAS blow through MAF sensor setup is like $300 bucks. They said it is good for way more power than I can make if installed in a 3 tube. I am not sure if that is 3 ID or OD. Anyway they say 800whp on a 3 tube.

Last edited by pcampbell; Today at 07:56 AM.
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