Hello everyone, brand new user here.

Got a 98 base vette that I installed hand ported 799 heads, TSP Bald Eagle cam, and longtubes. Been searching for weeks trying to decide what intake would be a good streetable intake other than one from Fast. I want it to fit under the hood but spending a grand for an intake is a really hard sell to me. Are there any decent options? Not looking to min/max my power but something other than the stock ls1 intake.

 

I would say that an LS6 intake is probably your best bet for the money.

 

LS6 intake is probably your best bet if the Fast 92 and 102 are too pricey. It will pick up a good bit vs the LS1 intake. I noticed a diffence even when my car had the stock cam.

 

LS6 or LS2 if you can find one of LKQ, Rock Auto, or ebay. If you are super into Budget TPIS will cut the snout off an LS6 intake and put on a 90mm snout.
https://tpis.com/products/90mm-ls6-m...35195437678754
(LS2 Intake)
https://www.ebay.com/itm/294437005821?epid=23038039993&hash=item448dd029fd: gAoAAOSwi~xhWqJq
(LS6 Intake)
https://www.ebay.com/itm/255163230344?epid=657278392&hash=item3b68e9e888:g: ykIAAOSwk~ZaCeDa
(LS6 Intake)
https://www.ebay.com/itm/32481765572...EAAOSwONxhXLXN

 

Between buying an LS6 intake, and getting it modified, you might as well just spend the extra $100-150 for a Fast 92. You might even be able to find a used Fast for around $600.

 

Having TPIS do a 90mm snout to an LS6 intake works out well if you already have an LS6 in my experience. I have two cars w/90mm TPIS/LPE LS6 intakes.

Otherwise might as well get the Fast 92, because it can be ported effectively for more gains later.

 

Did you ever have any dyno info or gains that you picked up with the Stock LS6 vs. the TPIS 90mm Snout on the LS6? I know you have spoke highly of it, just was curious? Thanks

 

Did a fair amount of research long ago, LPE used to have dyno info on their site in mid 2000's. Their research and others was convincing enough I wasn't going to spend $$$ dynoing a stock LS6 vs a TPIS 90mm Snout LS6.

My PC that had all of that saved on it is long gone. I do recall the LPE tech explained that on bigger cube motors the Fast 90 would have an edge of at least 5 hp vs 90mm snout TPIS/LPE LS6 intake on a 427. Sometimes closer to 18 hp with more rpm with bigger cams etc.

Bottom line those LS6 runners will max at ~270 to 275 cfm of air. The Fast 90 can do 280 cfm to 285 cfm. The redesigned Fast 92 should do a bit better etc.

I did do a dyno test in 2016 of a ported 90mm snout TPIS/LPE LS6 intake vs a Fast 90mm. The two were close with 90mm snout TPIS making 2-3 whp more. This was all on my 91 RS with a 383 LS1 and 229/229 cam etc.

I doubt the porting on the 90mm snout TPIS/LPE LS6 intake was worth much if anything based on later testing. I picked the wrong vendor

I should have asked CarTek/CarTek Racing to do the port work on the LS6 runners. CarTek had a proven 7 whp gain with Juilo's work.

However if the Fast 90 had been ported by a skilled person I think it would have won by a few whp even against the best case.

My 91 RS still has 90mm snout TPIS/LPE LS6 intake. No issues etc. Likewise my 02 Z28 has a TPIS/LPE LS6 intake...again no issues. One day a new top end may go on the RS along with a new intake. In a few years it maybe time to call Tony Mamo for a new top end and upgrade.

The Dorman LS2 is also pretty decent. Some of the ones I tested had various degrees of quality as Dorman tweaked the process but I would imagine Dorman has that well dialed in now.

 

Alot of good info there, thank you for sharing.

Question if you heads are flowing above the " LS6 runners will max at ~270 to 275 cfm of air. The Fast 90 can do 280 cfm to 285 cfm" at what point would you be looking towards the LSXR or Atomic. I am a huge LS6 fan don't get me wrong just asking, I made almost 1,000hp on a LS6 intake (See Sig), but just was more wondering, if you have really good heads, then the restriction would be the intake at that point correct? And at that point if your wanting to max or match the combo to head flow you would need the LSXR or the Atomic correct?

I dont know the CFM of either one of those intakes either, I am just assuming they are the next logical step up.

 

Those are excellent questions. For a 20+ year old factory intake the LS6 is still a pretty cool intake IMO So I follow what you're saying.

Both the LSXR and MSD will flow a greater percentage of air or lose fewer cfm of air flow even with stock heads that flow ~235 cfm. On the flow bench LSXR/Atomic seem to have greater power potential. Track and dyno results generally back that up. However steady state on a flow bench is only a very crude approximation of what a running engine does with air flow. There can be a few odd ball exceptions. Track and dyno rule for making the decision.

Lot of folks are like slap the LSXR on a stock motor or any other for a nice gain. I think it's a little more complicated depending on budget, can the 102 deal be tuned to drive well by the available tuners etc.

My personal pet rule of thumb is for even a stock LS engine in a car a 90mm snout LS6 or TBSS or Dorman LS6 is the minimum.

However if the heads will flow 235 cfm on an accurate trustworthy bench the ported LSXR is definitely in order if expert driveability tuning is available if one is after the max gains. If high rpm 7000rpm + is wanted the ported Atomic should be on the menu.

A tuner I know more or less said for a lot of folks with a 346/383 the 102 stuff is drifting toward over kill unless it's a hard-core build that's more strip than street. For 400+ cubes definitely 102 Fast or Atomic. Of course it depends on what the customer wants or thinks they want and how much is available to spend.

Personally another 90mm snout TPIS/LPE LS6 intake was just perfect for my 250,000 mile daily driver 02 Z28. The Mamofied LSXR stayed on the shelf for another project

 

Which of course might be totally irrespective to what might actually work best..... ignorance and vanity CAN AND DOES overrule the logical thought process.