LS7 serpentine belt configuration

[Grant S]

I couldn't find any pictures on the set up, but from I read it only drives the water pump not the accessories. But if you could find a system that drove all your components the noise from all the gears whining 12" behind your head would probley drive you insane. Just the gear driven timing sets can be heard at 40 feet, the poor mans supercharger.
Cheers,

 

[David Stephenson]

How about just having a big alternator using it to power everything else? Water pump, AC, whatever.

 

[Michael]

My engine is an LS2, with an LS1 water pump (due to clearance issues with the GTM frame), but the layout is the same as the LS7.

Based on a suggestion from one of the guys on the ffcars (GTM) forum, I decided to use the CTS-V Alternator and Bracket. To me, it sounded like a good idea since it provide more strength in how the alternator is attached to the engine. It also used the same alignment path for the belt, so I didn't have to worry about shimming it or adjusting it with fender washers, etc.

I'm also using the lower tensioner between the Alternator and the Water Pump bell to keep the belt in as much contact as possible. (It's part of the CTS-V Alternator Bracket). I was never 100% sure whether or not this would solve the belt squeal issue, until we ran the engine for the first time. It's been run pretty hard on the Dyno, as well as normal idling and revving in the garage, and so far I've not heard any squeal from the belt.

If I remember right, to buy the CTS-V Alternator, Correct Pig Tail, Bracket, Tensioner, and correct hardware cost me in the neighborhood of $500.00+. (But it seems to be working).

 

[Grant S]

Can any one tell me if jmichaelbaskin aka, the Stig set up will work on an LS7 ?
Cheers,<!-- google_ad_section_end -->

 

[Doc Kaler]

Grant,

Yes, with the alternator in the lower CTS-V position, it should fit.

 

[Will Campbell]

Grant,

Yes, with the alternator in the lower CTS-V position, it should fit.

I agree with Doc, but it should be pointed out that the water pump pulley on that engine will not clear the chassis as installed. The LS7-style water pump should be used.

Also, you should carefully check the water pump inlet orientation to be sure it will clear the rest of the hoses, etc in that area. The one in the picture points in a direction that works for the GTM, but may not be optimal for the SLC.

And as has been mentioned before, the WP outlet also needs to be modified to clear the chassis.

 

[Grant S]

Thanks and Yes the mods to the pump were done by Fran at RCR they are both pointing downwards. So this may be a good way to go with out using a lot of custom made parts?

 

[Michael]

Grant,

Here are the Part Numbers for the CTS-V Alternator / Bracket / Pulley Idler.

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I bought mine as individual parts from GM Parts Direct.

www.gmpartsdirect.com

12578550 Generator Bracket
25766345 Generator
12568996 Pulley / Idler


Hope this helps.

Mike</o>

 

[Michael]

http://www.chevroletperformance.com/_res/pdf/GMPP_2012_Catalog_Update.pdf

GM Performance Parts Catalog. Page 246. Shows the CTS-V Accessory Drive Kit, as well as the Corvette Accessory Drive Kit. Each of the kits break down all individual part numbers that make up each kit.

 

[Michael]

I agree with Doc, but it should be pointed out that the water pump pulley on that engine will not clear the chassis as installed. The LS7-style water pump should be used.

Also, you should carefully check the water pump inlet orientation to be sure it will clear the rest of the hoses, etc in that area. The one in the picture points in a direction that works for the GTM, but may not be optimal for the SLC.

And as has been mentioned before, the WP outlet also needs to be modified to clear the chassis.

Will,

Your absolutely right. In order to use the LS2 or LS7 in the GTM, we have to use the LS1 water pump for clearance of the Cross Bars of the frame.

As well, I'm running a Custom Kooks Header and exhaust system which caused clearance issues with the (LS2) A/C Compressor. I ended up needing to use the Corvette LS1 A/C Compressor, Bracket, and Tensioner, in order to have the header clearance between the header tubes and the A/C lines that I needed.

For the SLC, you would definitely need the lower profile LS7 pump.

 

[Grant S]

Thanks again Mike I ordered the Alt and pulleys today from GmpartsShop.com they were slightly cheaper but they also give a 30 day warranty I used a diffenent Alternator PN# 25925447 it is a 150 amp from the 2011/13 the 25766345 is a 140 amp I swapped my cooling fans out with two big Maradyne fans they pull hard but use a lot of power. Just need to come up with the upper pulley bracket.

 

[Ken Roberts]

Grant, is your water pump outlet on the same side as the inlet connection or is it on the other side? Older LS2 and early LS3 water pumps have the inlet and outlets on the same side. Newer LS3 and LS7 water pumps have the outlet on the opposite side.

If yours is the newer style mounted on the other side than you might not be able to use the setup that "The Stig" shows. That custom upper tensioner might position the belt right in the way of the water pump outlet fitting.

Sorry Grant, I just read in post #3 that your inlet and outlet are on the same side.

 

[Ken Roberts]

Here are a couple of sources for the 2011 CTS V Denso alternator connector EFI Connection - Connector Details

http://www.currentperformance.com/Connectors/LS2_LS7.html

 

[Michael]

Thanks again Mike I ordered the Alt and pulleys today from GmpartsShop.com they were slightly cheaper but they also give a 30 day warranty I used a diffenent Alternator PN# 25925447 it is a 150 amp from the 2011/13 the 25766345 is a 140 amp I swapped my cooling fans out with two big Maradyne fans they pull hard but use a lot of power. Just need to come up with the upper pulley bracket.

Hi Grant,

I'm glad this helped. As I mentioned in my PM to you, the upper bracket that you see on my engine is a bracket that was made by Factory Five Racing, and shipped as part of the GTM kit.

I do know that factory five sells individual parts to customers. If you're interested, you could call them and buy one for your engine. I'll read through my build manual and get you a part number. The bracket fits LS1, 2, 3, and 7 engines.


Mike

 

[Michael]

Grant,

If you're interested, the part number for the upper Tensioner Bracket is FFR# 25360.

This will help you relocate the tensioner to alow the belt to clear the water pump bell/pulley.

Not sure what the price might be for it, but I can't imagine that it would be very expensive.

www.factoryfive.com

(508) 291-3443

 

[Grant S]

Thanks Mike,
I am going to wait for the Alt and mounting bracket to show up,
I am thinking of fabricating a bracket to mount the Crane or MTI tensioner at the top of the engine.
Have a look at this MTI Racing LS2 LS3 LS7 Billet Belt Tensioner - YouTube
If anyone know's why it won't work please jump in.
Cheers,

 

[Ken Roberts]

The MTI tensioner has the extra leg that mounts to the cylinder head. If you move it to a different position than you'll most likely be cutting this extended length leg off. It's mainly intended for the demands of a supercharger. Kinda overkill in my opinion.

I use the Katech tensioner. Billet Belt Tensioner -- Katech Performance Online Store

 

[Doc Kaler]

That's the same Katech tensioner I have for the Gilmer belt-driven external Aviad oil pump. It will clear the water pump, etc.

 

[Ken Roberts]

Grant, your message box is full. Delete some messages or you will not be able to receive more.

 

[Jack]

Ditto on the Katech tensioner, nice piece.