Mini compressor/less CID output?

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kris396ss
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Joined: Sat Sep 15, 2018 9:02 am

Mini compressor/less CID output?

Postby kris396ss » Sat Sep 15, 2018 9:10 am

Hey guys, I'm building a 96 Impala SS with an LS engine/LSA supercharger and I ran into one major snag with the project.

I can't fit a full-size AC compressor unless I go to a different accessory spacing and that creates issues with the supercharger drive (I'd have to run the supercharger and accessories on the same 6 rib drive instead of the supercharger on an independent 8 rib like the factory does).

I notched the chassis, looked into many different high mount aftermarket brackets but there's just no good way to do it without compromising the blower drive.

I found out about the SD7B10 Sanden "mini" compressor and according to my measurements, it WOULD fit using the factory drive spacing. My issue is, I don't want to sacrifice any comfort on this car. I want myself and my passengers to stay cool when stuck in gridlock NYC traffic on a 95 degree day.

The SD7B10 only has a 6.1 CID output compared to the factory AC compressor for the 96 Impala which had a 10 CID output I believe. My research tells me the SD7B10 can handle higher RPM's, so it will cycle less frequently at higher engine speeds and likely perform just as good as the larger compressor but everything I have read says it would have a diminished output at idle because of the smaller displacement. that's such a vague answer though, I don't know if that means it'll have a 5 degree temp difference compared to the full-size or if it'll blow warm air on a hot day.

Anyone have experience with these compressors? How do you think it would work when running in a system like the Impala's that was designed for a larger output compressor? Is there anything I can do to better match the system to the compressor so that using it WON'T compromise comfort?

Thanks in advance!
ice-n-tropics
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Re: Mini compressor/less CID output?

Postby ice-n-tropics » Sun Sep 16, 2018 1:47 pm

I'd modify your Impala OEM AC to only use recirculated air (not 20% OSA) and a additional 100% hot heater water shut off in Max AC mode. Then your OEM AC would work as good as a Vintage Air HVAC replacement.
Additional Dynamat floor, under hood evaporator housing and firewall insulation helps.
Vintage has several options for SD7H10 mounting brackets.
Eliminate the accumulator and use a TXV and reduce total oil to 5 oz w/o accumulator.
Aim for a drive ratio which keeps the compressor crpm optimized at idle w/o just exceeding max recommended rpm at max engine erpm. Optimize window tinting.
Optimize condenser air flow for max heat dissipation and your OK with SD7B10.
Mount R/D fowaward of hot engine compartment next to condenser of in cooler wheel well.
Paint car white.
Ref "How to Air Condition Your Hot Rod "from Vintage Air.
hotrodac
kris396ss
Posts: 4
Joined: Sat Sep 15, 2018 9:02 am

Re: Mini compressor/less CID output?

Postby kris396ss » Mon Sep 17, 2018 4:22 pm

Ice, thanks for your reply! I'll be completely honest, most of what you said is foreign language to me LOL. I'm probably less than even a novice when it comes to AC systems. I have repaired them once or twice but don't even fully know how they function. I have just been picking up some info here and there while researching for this build.

I have till next summer to learn though, so I have plenty of time to make sense of some of that. If I can get this mini with whatever reasonable upgrade parts to work as good as the 10cid compressor did with the factory mid 90's AC system I'll be happy!

I do plan on using ceramic tints, but the car is also black and unfortunately that won't change LOL. Already dynamatted firewall from the inside and I'm working on the floor. Also thinking off spacing some sort of large heat extractor/hood louvers into the hood since the car is supercharged and I'd like to get all that heat from the LSA blower out of the engine bay when sitting and idling.
kris396ss
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Joined: Sat Sep 15, 2018 9:02 am

Re: Mini compressor/less CID output?

Postby kris396ss » Tue Sep 18, 2018 9:24 am

I received a reply back from Vintage Air that honestly was not too helpful.

"Using our 7B10 compressor on a vehicle running an OE evaporator and condenser is not recommended due the volume being insufficient to operate an OE system"

I pretty much knew that already, but I was hoping they could assist me in adapting my system to better work with the SD7b10. I replied back asking if there was any advice they could give on parts that my be somehow retrofitted to my system to work better with the SD7b10, I'll let you guys know what they say.

Swapping the condenser out for something else should be no trouble at all. I could weld up whatever custom mounts I need to fit whatever condenser would work.

The evaporator is a different story. Not sure how easy/hard it would be to stuff a different evaporator core inside the box but I'm sure it could be done somehow. But if I were to replace the evaporator and condenser with lets say parts that Vintage Air uses on their SD7B10 setups, would anything else have to be reworked in the system to function correctly?
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bohica2xo
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Location: Las Vegas, NV

Re: Mini compressor/less CID output?

Postby bohica2xo » Tue Sep 18, 2018 10:45 am

Hard to picture the issue with the OEM drives, but could you simply relocate the compressor and leave the other accessories on the 6 rib belt?

There are 8 rib compressors. Could you put a larger displacement compressor someplace more accessible using the supercharger belt?

For instance there are 8 rib FS10 compressors on the Thunderbird Supercoupe.
http://www.ackits.com/comp-fs10-pv8-3368

.
kris396ss
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Joined: Sat Sep 15, 2018 9:02 am

Re: Mini compressor/less CID output?

Postby kris396ss » Tue Sep 18, 2018 11:25 pm

bohica, the factory LSA uses 3 separate drives; one to run the 4 rib AC compressor, one to run all other accessories (6 rib) and 8 rib dedicated blower drive. I have checked out just about every front drive kit made by every brand and almost all of them have some pretty significant downsides (imo) or are just flat out too pricey. Most of the cheap ones place the AC compressor on its own drive and and run the blower and accessories on the same drive which is an issue for a few reasons in my opinion.

There isn't much room, but may be a way to place a full size compressor somewhere in the accessory loop but that would involve me designing a whole new accessory loop, I've built supercharger brackets/drives before but a whole accessory loop is a little much for me haha

I heard back from Vintage Air and they were a bit more help this time. This is what they said:

"The evaporator is where the problem is because that compressor would not put out sufficient volume to operate correctly.

I would recommend something large like the Gen IV Magnum or Gen II Super to cool a big sedan like that and the largest condenser that will fill the radiator surface area."

So it seems maximizing the system for the mini may be doable, and not too expensive being that I need to purchase a ne condenser anyway (mine was destroyed in storage).
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bohica2xo
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Location: Las Vegas, NV

Re: Mini compressor/less CID output?

Postby bohica2xo » Wed Sep 19, 2018 10:59 am

Accessory drive Tetris is just part of engine swapping.


I fully understand the desire to keep an 8 rib blower belt. I had a dealer installed Whipple in a 1993 Indy pace truck that ate 6 rib belts on a monthly basis. In my world blower belts have teeth...

I suggested the blower belt loop because it means only adding one accessory - and ignoring the old 4 rib belt. A lot less compromising than trying to make a reduced displacemernt compressor do the job. Grab an FS10 6 rib core & use it to hold in different places in the engine bay...

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