ADM lsa conversion pulley limitations solved!

[genius4m]

Hi guys

I was so disappointed when I decided to pump the power up in my camaro ss with adm lsa conversion

Seeing zl1 guys getting 23-24 rpm blower speed while I'm stuck with the SS accessory drive limitation

I bought innovators west's 8.00 inch lower " biggest you can fit in the ss accessory drive" with smallest upper adm offers which is 2.38

Didn't get much more than 22.800 blower rpm

And found out that we can fit 2.17 pulley in our blowers! From ZPE griptech

Got it 220$ shipped with hub and now im cranking it up to more than 24k rpm with zero issues, zero belt slip " yes it is 6 ribs setup! "

That is equivalent to 2.55 upper 9.1 the zl1 guys doing , maxing out the blower to its limits and more

No need for the crazy expensive zl1 accessory drive to max out our blowers, I wish I had known zpe earlier, ADM is hiding that magical pulley from us all that time🤣

BTW:
CAR 2010 A6 with 408 stroker L77 block and blower cam, stock heads stock blower 10.9 compression 13 psi boost with 8.0 lower 2.17 upper /93 fuel+meth

Go get some boost guys !

[fldrummer]

Dyno numbers?

[1LEric]

Does the lower affect your alternator or ac ?

[jrhagen]

I have a 2.5/9.5 8 rib on one of the ADM kits. No issues.

[1LEric]

Nice I’ll be looking into this

[genius4m]

we'll be coming back the dyno numbers next week, street tuned

The lower is only 10% larger, no effect or what so ever
Plus the ac part is the same as stock, used same ac belt of the stock lower.


The 8 rips conversion is much more expensive, I know adm offers it but in my case, settled everything to the max with much less $$$

[genius4m]

Sorry for the late, I've been through a lot blowing my head gasket and getting broken heads ��

Wrong belt size caused a slight belt slip, I have solved it and my smart ass pushed the pedal wot to try out if the belt slip is gone, yes it did but that gave me 1 more psi " tune was not adjusted for 14 psi" and ka booom

Anyhow, dyno number is 686 thru 305 slicks with 20 psi pressure.

This is With the minor belt slip..

The stock heads are choking my 408 , want to buy blueprint 270cc heads with 77cc combustion chamber, haven't seen any review about them idk, exhaust flow in these are just amazing.

Any feedbacks?

[RockSVT]

I'm guessing that this pulley combo wasn't too great, it seems as though the OP changed setups right directly after this post (and won't respond to a PM) but he sold everything afterwards and went turbo. It seems like the general consensus is about a 2.5 or a 2.38 is as small as you want to run a 6 rib. Would love to hear if anyone has successfully ran a smaller upper without belt slip..

A lower would probably be a better idea, like this one: Dayco PBO81190SC10

[hammdo]

6 rib setup from ADM was not designed to run the way the op setup. The lower not only runs the blower faster but ALL the accessories faster.

ADM was not hiding this ‘magic’, they setup this pulley system for ‘safe’ and dependable operation.

I beta tested and wrote the install guide for the ADM 6 rib setup. Andy knows what he is doing and I can assure you, if you want to run the upper and lower pulley setup, 3 belt is the way to go — GM did the 3 belt setup this way for a reason — and ADM made sure to follow that. I now have the ADM 3 belt system and it works great...

Andy (at ADM) is a damn smart man and he knows what a safe and dependable setup is...
The op experimented and obviously made a mistake by not retuning — as he stated. As they say, pay to play. I’m sure he was very happy with the turbo setup.

2.5x is common but the smallest I’ve seen is 2.38 — on the 6 rib.

My 3 belt is running 2.45 griptec and 18% lower — about the max I’d run on the 3 belt setup.

-Don

[RockSVT]

^ I think you're right but it's too big of an investment. Coming from an 03 Cobra the only accessory on the blower belt was the Alternator and you only had to slow it down after you went bigger than a 4lb pulley which was 1" bigger than stock and actually the same diameters as stock to the Powerbond on our cars: 7.5" stock to 8.5" for the Powerbond so I think the Powerbond is an option for us 6 rib guys holding off on 1.5-2k worth of a 3 Belt set-up. I agree its the way to go but is so grossly overpriced, I would half be tempted to pull mine and go Turbo instead. You could however make a 8 rib 2 belt setup using the Powerbond or Innovators West and come in under 1k... I'm undecided

On a side note I made my own 110mm idler so that I could run a really small upper and still get max belt wrap.. may not end up using it but it was a fun project anyways. I'd post a pic but not sure how on this forum

[ADM PERFORMANCE]

1.5-2k worth of a 3 Belt set-up. I agree its the way to go but is so grossly overpriced

[RockSVT]

^ I guess you're agreeing with me? The best option (for adjustability and belt slip) is the most expensive and not really worth it on this blower is what I was trying to say. If it was a 1k hp capable Whipple, Bell or TVS then maybe but not on the LSA IMO

[hammdo]

Here is the breakdown:

4 brackets:
-Power Steering
-idler
-ac (if keeping LS3 ac compressor, a special bracket/bolt is needed — custom made), have to notch the RS Motor Mount pedestal or trim the ac compressor. If not keeping, an LSA/ZL1 ac compressor.
-alternator

Lower pulley:
-ATI (with OD pulley) or factory

LSA water pump

Belts (8 rib, 6 rib, ac belt)

I did the 3 belt setup with ATI Lower and 18% OD pulley since I was building an LSA engine for my road course setup.

800+ RWHP/RWTQ

So, it all depends as you say — if you want to do this because of price. It’s pretty much all GM LSA parts and GM has a kit for it. ADM tweaks it for the LS. It is crazy what GM charges — one could buy used brackets etc. and cut costs.

-Don

[RockSVT]

^ I'm a Tool and Die maker by trade. So maybe I could do my own fabrication on the A/C bracket. That would make it a little easier on the wallet.