Lets Talk Alternator - Again

[Dan Carter]

Ok. I have the RCR LS3 accessory kit. To install the alternator, the kit provides two spacers (~10MM) to mount an alternator in the lower passenger side of the engine in what appears to be two threaded holes in the block (teeing this up before buying an alternator). My kit contained no other bracket for support. I guess this must work, but there has to be forces that IMHO will eventually fatigue. (RCR recommended GM 8247 alternator - 2002-2005 truck 105 AMP)

I have read two solutions, CTS-V bracket and alternator or the Pontiac G8 GXP bracket and alternator (seems to hold alternator better)

Will either of these solutions complement the RCR LS kit, aka buy the G8 or CTVS kits and install it in conjunction with the rest of the RCR kit (probably requires a longer serpentine belt)?

If so, which year car for either solution.....

 

[Fran Hall RCR]

The alternator mounts to the block and does not need another bracket, the tensioner takes up the slack as its designed to do.
Brittany has a couple of backordered parts for you but she has been off with food poisoning.

Our front dress package works great ...

fyi.
if you already have a thread started about the alternator, please post in that thread to keep items condensed for easier reference for others.

 

[Dan Carter]

Thanks for chiming in Fran. Man hate to hear about Brittany, hope she feels better soon. Tried to search a specific "alternator" thread, but came up empty. I read things at times, then can't find it again, sorry.

As for the mounting, what got my attention is there are only two attachment points with the two bolts, so it just seems a lot of torsional pull at those two points over time.

Do you still recommend the old truck alternator, or is there a more current model?

How many AMPs is enough? I have seen a lot of differing opinions, but hard to tell what configuration the car is in comparison.

:thinking:

 

[Fran Hall RCR]

Depends what you plan to run inside the car
Big stereo , infotainment,neon lights , glitterball etc

 

[Dan Carter]

Radio/gps combo (not into big stereos)...love the sound of thundering V8. Rear view mirror system. That's about it, but glitter ball.....hmmmmm.

Gues minimum of 105 AMP. 120 would be better I guess. So got to find the right style for fit with right wire plug combo.

 

[Will Campbell]

There's a page on this on the SLC wiki: https://slctech-slcbuilderswiki.pbworks.com/w/page/103514175/Alternator

 

[Roger]

Radio/gps combo (not into big stereos)...love the sound of thundering V8. Rear view mirror system. That's about it, but glitter ball.....hmmmmm.

Gues minimum of 105 AMP. 120 would be better I guess. So got to find the right style for fit with right wire plug combo.

105A sounds ample.

 

[PeteB]

Ok. I have the RCR LS3 accessory kit. To install the alternator, the kit provides two spacers (~10MM) to mount an alternator in the lower passenger side of the engine in what appears to be two threaded holes in the block (teeing this up before buying an alternator). My kit contained no other bracket for support. I guess this must work, but there has to be forces that IMHO will eventually fatigue. (RCR recommended GM 8247 alternator - 2002-2005 truck 105 AMP)

I have read two solutions, CTS-V bracket and alternator or the Pontiac G8 GXP bracket and alternator (seems to hold alternator better)

Will either of these solutions complement the RCR LS kit, aka buy the G8 or CTVS kits and install it in conjunction with the rest of the RCR kit (probably requires a longer serpentine belt)?

If so, which year car for either solution.....

Here's a pic of my engine with accessories installed using the RCR front dress kit

 

[Dan Carter]

Pete

Which alternator and part number is that. Do you recall the bolt sizes you used...simple enough to figure it out, but while I'm asking......

Looks clean and simple enough. Picture is worth a thousand words.

Out of curiosity, Anyone have some alternate solution pictures they might share .....

 

[Mark]

Hey Dan, Just looking at Pete's picture I have a feeling you can't mix and match solutions. The location of the PS idler looks too low to me to allow you to use the CTS-V setup, you will most likely have clearance issues with the belt between water pump and idler.

 

[PeteB]

I don't remember the part # for the alternator - I'll have to look through my receipts. The bolts are metric but I don't remember the size.

 

[Allan]

The CTS-V alternator and mount can be used with the RCR set up, the belt length is a bit different though.
I use this alternator:
ACDelco 25766345

 

[Mark]

Allan, are you using the idler pulley on the CTS-V bracket or skipping it? I'm having a hard time imagening this routing. I included a shot of my setup and it's awefully close even though my belt is angled higher.

FYI when using the CTS-V bracket you must use one of the CTS-V alternators, they're very specific and have a cast in 3rd bolt braket for the side of the block. There are two CTS-V alternators, part# 25766345 as mentioned by Allan has a simple turn on lead (Terminal L) that's just a straight voltage, used with older ECUs. The newer CTS-V alternator(~2007+) uses pulse width modulation to properly turn it on. You must match the alternator to your ECU otherwise it will not regulate properly(fixed at 13.6V).

Some good reading on this subject:
09-11 cts-v alternator wiring - LS1TECH

 

[Eric McClellan]

I used the standard RCR alternator setup.

I think the alternator came out of a Denali or Suburban or something like that. I remember I got it right on the first try. Autozone/napa/whatever had one on the shelf.

Secondly. I didn't have any belt slip, i know people are worried about that. Mine didn't.

Third, power output was fine at the 105A version of the truck alternator for what I was doing. Constantly saw 14.5 or higher on the gauge.

Finally... About it slipping or getting ripped off at high RPM's... I revved mine up (more than once, race track ....) to about 6,500rpm-ish (multiple times, for sustained periods, gotta love GM crate motors!) and no issues.

~Eric

 

[Alex]

i havn't had any issues with belt slip or misalignment after 5yrs.

 

[PeteB]

I used a 321-1811 alternator.

 

[Allan]

The RCR set up works without any issues. You can use the CTS-V mount with the RCR set up but not the idler pulley.
Or you can use the CTS-V set up with the tensioner in the stock position along with the mount, idler pulley, belt and the pulley made to replace the power steering pump.

 

[Del]

I used a 321-1811 alternator.

Thanks for this part number Pete. I ordered the RCR front dress kit and was getting kind of confused on what to order. Since it worked for you, should have no issues for me, so thanks!