AR 1.5L...worth it?

fastsc92

Registered User
I have a local guy I know with a 1.5L AR. I assume that it's going to be too small for our engines. Has anyone seen a flowsheet for one? Dave, any comments to add?
 
still seems that I'll have to OD it a lot to get the boost in the 18psi range. Again, these are assumptions as I'm still looking for a flow sheet.
 
You can't overdrive the bejebus out of a twin screw like you can an Eaton because the male rotor spins much faster than the input shaft. 18,000rpm should be considered absolute redline. Efficiency starts to fall off pretty badly after about 16000rpm. I would not use that on an SC.
 
Yea, they are only rated for 13000 RPM so I was thinking it would be no good. No wonder why KB upgraded the stang guys to the 2.1L....
 
Yea, they are only rated for 13000 RPM so I was thinking it would be no good. No wonder why KB upgraded the stang guys to the 2.1L....

All twin screws are rated at 13000rpm continuous. KB guys unofficially take theirs to 18000rpm and Whipple even advertises a 17000rpm limit on their 1.6L but they are all the same design. AR just refuses to give their blowers a redline above that which they can sustain indefinitely. I have not seen where a twin screw failed due to rpm but I'd rather not be the one to find out.
 
Agreed. I can get a brand new unit from Optcon, but I was looking for a take-off unit to save a few bucks. Buying one direct is actually cheaper than I thought....plus I can get any size I want from 1.7 to 2.4 all at the same price (minus snout)
 
I think you may be limited to HP with the 1.5 but I cant see it not being an upgrade of sorts.

However I have seen twin screws that have seized due to RPM's..So that is definitely something to consider.
 
I think you may be limited to HP with the 1.5 but I cant see it not being an upgrade of sorts.

However I have seen twin screws that have seized due to RPM's..So that is definitely something to consider.

Maybe an old one. There have been many design and bearing changes over the years. Not to mention that a lot of failures on earlier units were traceable to things other than pure rpm. If you speak to someone who actually services these blowers (not me since I know very little) you'll find that failures of any kind are rare.

Anyone running a 2.2KB unit on a Cobra or Lightning is spinning it wayyy faster than they were ever intended to run. The 2.2L is almost an ideal size for the SC engine and we don't rev near as high as a DOHC if that puts any perspective on anything.
 
back to the drawing board again.... Hell I may just buy one from Opton dirrect :rolleyes:

It's Opcon. :p

I can't imagine buying from Opcon directly possibly being cost effective. With overseas shipping included the end price would be about the same as a Whipple. If you want to buy a compressor by itself, I suggest contacting Vortec. I am also an Opcon dealer but I do not stock units at this time so then we get back to the whole shipping thing again.
 
Opcon, Opton, Acorn, whatever.... :p

I guess I'm just getting ahead of myself. I had two local deals that I just came across and it sparked my interest once again. Months ago I contacted Lysholm direct and was surprised at the pricing of a compressor. The shipping was relatively cheap, but the price accociated with customs was unclear. Not to get too into pricing, but the cost was less than what KB sells their replacement compressors for.

Anyhow, I guess I'll just wait until something else crosses my path. I have too many side projects now and I still need a purdy car to put it in.
 
It's 1.33L but it's also on a smaller case and port design. It's one of the bigger SR3 compressors used on Miata's and stuff like that.

The compressors are priced separately from the drives and pulleys so don't forget that and shipping is retardedly expensive on individual units. Shipping overseas to an individual isn't so bad, but when you are dealing with a merchant, there are all sorts of fees involved. I think it cost me almost $400 to have a single unit shipped here a couple years ago.

Vortec is now the US distributor for Lysholm so if you want to buy a new one, contact them. You have to be really careful what you get used. Since they are kind of hard to find new and people don't often want to give them up, used prices are typically way higher than they should be. I would be very cautious about anything used.
 
You definately do not want to ship anything direct from Opcon overseas. I paid $300 for shipping and customs fees just for a nose drive :eek:!
 
Also when I talked to Lysholm the sales guy told me that they were phasing out the LYS-OA SR4 series (OA 420MX, OA 417MX, etc.) for the LYS-series . Basically he told me to jump on it if I was dead set on using that case design and displacement range as he had no idea when they were actually going to be out stock. Pricing a few months ago (minus shipping) for the compressor AND snout AND pulley was very close to what KB is charging for a compressor unit. I'll have to look into Vortec and see what's up with them.
 
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