LQ9 with LS1 Alt Bracket - are two bolts enough
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LQ9 with LS1 Alt Bracket - are two bolts enough Just got my LQ9 370 from TSP. Was told it would be a slam dunk install converting everything over from the LS1 347 except that a bolt hole for the alt needs to be drilled and tapped first. Although I asked for and paid them to do it - they did not - leaving me to do it myself or have the installer do it.
However, looking at my LQ9 block there is only one tapped hole on the bottom of the block neart the front cover. There is no machined boss on the block above that hole for a third bolt to hold the alternator bracket on. I don't doubt that two bolts are sufficient to hold just the alternator on the block.
But I have a D1 supercharger hanging off the alt bracket.
So question is this? Are just two bolts sufficient to hold the J bracket without twisting at high boost? Or am I going to have add a brace between the j bracket and one of the bolts holding the oil pan on. Only other option might to use one open tapped hole on the face of the driver side head and add a machined brace to attach to the alt bracket where the bolt protrudes through the alt bracket but no hole in the block to screw it into.
Hard to believe that all of the write-ups and posts I researched plus questions I asked of TSP - that with an LQ9 block - there is only one tapped hole for the alt bracket and that there is only one machined boss for a second bolt to be drilled and tapped rather than two that are necessary for three bolts.
Perhaps not a big deal with just an alternator, but I think it is with a ProCharger hanging off of the bracket.
So are two enough or not? What's everyone else doing for this scenario?
However, looking at my LQ9 block there is only one tapped hole on the bottom of the block neart the front cover. There is no machined boss on the block above that hole for a third bolt to hold the alternator bracket on. I don't doubt that two bolts are sufficient to hold just the alternator on the block.
But I have a D1 supercharger hanging off the alt bracket.
So question is this? Are just two bolts sufficient to hold the J bracket without twisting at high boost? Or am I going to have add a brace between the j bracket and one of the bolts holding the oil pan on. Only other option might to use one open tapped hole on the face of the driver side head and add a machined brace to attach to the alt bracket where the bolt protrudes through the alt bracket but no hole in the block to screw it into.
Hard to believe that all of the write-ups and posts I researched plus questions I asked of TSP - that with an LQ9 block - there is only one tapped hole for the alt bracket and that there is only one machined boss for a second bolt to be drilled and tapped rather than two that are necessary for three bolts.
Perhaps not a big deal with just an alternator, but I think it is with a ProCharger hanging off of the bracket.
So are two enough or not? What's everyone else doing for this scenario?
Last edited by dlandsvZ28; Aug 16, 2018 at 10:37 PM.
I had no issues with the SDCE bracket and my block doesn't have a boss either. If it did, I would have tapped it for the alternator bracket on the turbo conversion but it isn't there.
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As for boost am going to start with a 7.65 crank pulley and 3.9 head unit pulley. I think that should put me at about 12-14 lbs of boost and still be below the max rpm threshold of the D1.
Still puzzles me why so little mention of the missing boss for the third bolt on the lq9 block.
As snider says, I think the best option will be add a brace from the bottom of the J bracket and attach near the oil pan.
In the near future I have someone that will modify the j bracket to move it outward about 3/8 inch. This will allow a 145 amp alternator to be installed. With a 145 amp alt in its current location the 145 amp alt pulley touches the bolt head on the blower pulley. Plus there will be enough room on the bottom the j bracket to add an attachment boss for the extra bracket.
I also have a smaller pulley from the CTSV pulley system that fits perfectly on the Aster Bracket. It's a little larger and has two larger bearings compared to the lower-most pulley on the Aster Bracket that has only one bearing. That little pulley spins at extremely high rpms, so IMO two bearings distribute the heat and load more evenly.
Will send pics later.
Last edited by dlandsvZ28; Aug 18, 2018 at 09:26 AM.
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ICT Billit is here in Wichita, too. Will give them a call.
But if I can't find anything, I have a source that can make me one.
For those who suggest - just move the alt topside. The alt is not the issue. It's the two hole bracket the ProCharger J bracket hangs on.
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Subject: LQ9 with LS1 Alt Bracket - are two bolts enough?
Last sentence of first post: So are two enough or not? What's everyone else doing for this scenario?
Two will do Tap the boss for the second hole
did the same with my tsp 6.0
actually goes pretty quickly...
seems to be working well over 15lbs and a tight *** belt
did the same with my tsp 6.0
actually goes pretty quickly...
seems to be working well over 15lbs and a tight *** belt
Last edited by Jbonz/ss; Sep 6, 2018 at 07:45 PM. Reason: Wrong