Sanden compressor for Vintage Air Sure Fit gen IV

[showdog75]

I recently got a Vintage Air Sure Fit gen IV for my 63 Chevy II wagon. I'm in the midst of a ls2/t56 swap and looking to install the VA at the same time. This system is brand new never used but it didn't come with a compressor. I already have a sd7 but after talking to VA they recommend a sd709. They said the sd7 will work but won't be optimum. I'd like to hear from those that have used one or the other or both. If i understand the sd7 is over driven on the VA Frontrunner setup but I'm running gto/f-body accessories and want to run a low mount like the Alan Grove bracket. Is the sd709 that much superior to the sd7?

[Schwartz Performance]

Its my understanding that SD7 is a generic term to reference all SD7xx compressors. Same goes with SD5 ( SD508 ) .

Maybe I'm wrong, that's just what I've concluded lol.

-Dale

[Yelcamino]

This may be helpful...

SD Compressor Service Guide

[Twentyover]

...
I already have a sd7 but after talking to VA they recommend a sd709. They said the sd7 will work but won't be optimum.
...

What does 'wouldn't be optimum" mean? Does it mean that it's not optimum for them because they want to sell you a compressor? Or something else?

I have no gripe with VA- I've bought two frontrunners, two Gen IV's (the most recent was yesterday) and a Gen II from them, but in this case you need to call them out- they need to tell you what they mean.

If it's a 7 cubic inch compressor (maybe a 507 derivative?), and they reccommend a 9 (as they appear to do), I'd be willing to take a run at it with the 7 inch. The VA evap is smaller than most OEM's, and OEM's in general run about 10 cu-in. It's great having excess capacity, but if it's not required, then it' just excess. If you live in a hot climate, please disregard this paragraph

[showdog75]

What does 'wouldn't be optimum" mean? Does it mean that it's not optimum for them because they want to sell you a compressor? Or something else?

I have no gripe with VA- I've bought two frontrunners, two Gen IV's and a Gen II from them, but in this case you need to call them out- they need to tell you what they mean

Funny you mention, I called them today and this guy said the small sd7 will be fine and there wouldn't be much difference between the two. Go figure

[KUL FIR CHICK N]

I recently got a Vintage Air Sure Fit gen IV for my 63 Chevy II wagon. I'm in the midst of a ls2/t56 swap and looking to install the VA at the same time. This system is brand new never used but it didn't come with a compressor. I already have a sd7 but after talking to VA they recommend a sd709. They said the sd7 will work but won't be optimum. I'd like to hear from those that have used one or the other or both. If i understand the sd7 is over driven on the VA Frontrunner setup but I'm running gto/f-body accessories and want to run a low mount like the Alan Grove bracket. Is the sd709 that much superior to the sd7?

The answer to your question is a little bit mixed. When you refer to "SD7" I assume you mean the SD7B10, which is a 7 cylinder (SD7), 100cc/revolution (10) axial piston compressor. Here's the performance curve for the SD7B10: http://www.sanden.com/objects/SD7B10_Performance.pdf.Somewhere along the line, folks started calling the SD7B10 simply an SD7, which tells you nothing more than that you have a 7 cylinder compressor. The "709" that we list in our catalog is a SD7H15, which is a 7 cylinder, 155cc/revolution axial piston compressor http://www.sanden.com/objects/SD7H15_Performance.pdf . You should note, you can't extrapolate performance at higher RPM, as the volumetric efficiency of the piston compressors falls off rapidly as speed increases. The charts show the sweet spot of their performance curves.

All current Vintage Air Gen IV systems, including your '63, use the "Magnum" air handler, commonly referred to as the evaporator unit. For the purposes of this discussion, the Magnum is good for 17,000-20,000 BTU/Hr, depending on the rest of the system. The above charts show refrigerating capacity in kW. The conversion from kW to BTU is 1kW=3414.4 BTU/Hr.

The fact that you have a '63 Nova is important, as is the fact that it is a wagon. When we hear wagon, we are inclined to upsize components wherever we can, but the Nova throws a wrench into the equation. Your core support forces us into a smaller condenser than we prefer to use. A large compressor, combined with a small condenser, could lead to high head pressures if you don't have a bruiser of a fan package. When we design a SureFit kit, we are constrained by the majority of our customers not wanting to significantly modify their cars. We build a system that extracts the maximum performance possible within the package space available, while keeping vehicle modifications to a minimum. The best compressor for your installation, assuming a standard off-the-shelf-1st gen Nova Vintage Air SureFit system, would be either a 508 (the compressor that the system was developed and tested with, SD5H14 http://www.sanden.com/objects/SD5H14_Performance.pdf), or the SD7B10 (slightly lower peak performance but a great compromise of performance and package size). Another consideration is that 7 cylinder compressors tend to run more smoothly and we sometimes use a 709 in place of the standard 508 to solve NVH (noise, vibration and harshness) issues of certain compressor/bracket combinations. We ship the 709/SD7H15 with all Kwik Performance high mount LS brackets for this reason.

That said, there are plenty of guys out there that are all about maximizing performance, whatever it takes. That's how we're wired and we can help you do just that. If this were my car, and I live in Texas, I would modify the core support to accommodate a larger radiator and condenser, install the highest performance electric fans I could fit, insulate the heck out of the cabin, tint the windows, and use the SD7H15. Be sure to put a good alternator on the car that can keep system voltage north of 14v at all times. Testing on our in-house calorimeter has shown that 1 volt is worth as much as 2000 BTU to your system, so if you're driving around with an undersized alternator, and your voltage is hovering around 12v, you could be losing as much as 4000 BTU worth of performance. This is due to the reduction of airflow at the condenser fan and evaporator blower when they are underpowered.

With all of this said, our first Gen IV system was developed and tested on a '56 Nomad, complete with a Vintage Air Front Runner and SD7B10. It was well sealed, insulated and tinted. That car saw thousands of miles of testing, drove on several Power Tours and never failed to keep us cool.

Hope this helps.

Ryan Zwicker
Vintage Air, Inc.

[KUL FIR CHICK N]

Its my understanding that SD7 is a generic term to reference all SD7xx compressors. Same goes with SD5 ( SD508 ) .

Maybe I'm wrong, that's just what I've concluded lol.

-Dale

Correct

[KUL FIR CHICK N]

What does 'wouldn't be optimum" mean? Does it mean that it's not optimum for them because they want to sell you a compressor? Or something else?

I have no gripe with VA- I've bought two frontrunners, two Gen IV's (the most recent was yesterday) and a Gen II from them, but in this case you need to call them out- they need to tell you what they mean.

If it's a 7 cubic inch compressor (maybe a 507 derivative?), and they reccommend a 9 (as they appear to do), I'd be willing to take a run at it with the 7 inch. The VA evap is smaller than most OEM's, and OEM's in general run about 10 cu-in. It's great having excess capacity, but if it's not required, then it' just excess. If you live in a hot climate, please disregard this paragraph

Definitely has nothing to do with selling a compressor you don't need. That's not how we work. If you have a good compressor that is suited for the task, by all means use it. We do, however, strongly discourage using a used compressor from a take-out motor as you have no idea of its condition, oil charge, etc. When you kill a compressor, you pretty much kill the rest of the system, so it's best to start fresh.

Ryan

[showdog75]

Thank you VERY much Ryan, this is exactly what I was wanting to know. I'll be running a Entropy radiator with dual fans. I don't have the specs in front of me but the fans are supposed to be pretty good.

[KUL FIR CHICK N]

Thank you VERY much Ryan, this is exactly what I was wanting to know. I'll be running a Entropy radiator with dual fans. I don't have the specs in front of me but the fans are supposed to be pretty good.

That's a pretty nice fan and radiator package. I think you'll do well with that setup. One thing you might check is whether there is a baffle/divider between the two fans, within the shroud. We always incorporate a divider on our dual fan setups so that each fan has its own section of the radiator. Otherwise, you can end up with oscillation, increased noise and overall reduced performance vs a divided design.

[showdog75]

That's a pretty nice fan and radiator package. I think you'll do well with that setup. One thing you might check is whether there is a baffle/divider between the two fans, within the shroud. We always incorporate a divider on our dual fan setups so that each fan has its own section of the radiator. Otherwise, you can end up with oscillation, increased noise and overall reduced performance vs a divided design.

I'll be pulling the shroud today and checking it out. Thanks for the tip

[Fuelie Nova]

So Ryan if you are still watching this thread.... I have a 66 Nova, just installed a new VA GEN 4 made for the Nova (evap kit only) as my condenser and compressor from my older VA kit were newer. I run a Ron Davis radiator and dual fan setup made for the 66, if I do not mind modifying my core support can I install a larger condenser to help my cooling? I have a SD7H15 (new) compressed on my shelf as a backup for long road trips. My cabin is well insulated but no tinted windows.
Thanks
Tom

[KUL FIR CHICK N]

Hi Tom,

Yes, you can certainly upsize your condenser. Within reason, you can never have too large a condenser.

Ryan

[MAGONSTERZ68]

not sure if entropy rad/fan set up has a divider but wouldn't matter in my case as I am wired so both fans turn on on low drawing simultaneously but good catch. Could prove to be an issue for single fan operation.