How far can you really push an LQ9?
I have a fully forged 396 (Eagle 4340 crank, H beam rods, 4 bolt straight mains, still looking at a piston to use for boost as it was N/A before)
Advanced Induction 200cc cyl heads and custom grind turbo cam
twin AGP BW S256 turbos/T3 housing with a .82 A/R that should support over 950whp
Aeromotive phantom flex 450 fuel system that I'll be using with pump 93octane gas, should support the power I wish to make but if not, a boost-a-pump will feed me up to the 950whp mark.
My goal with the LT1 was to make around 700rwhp on pump gas with methanol injection.
Originally, like 6 years ago, I decided to keep the LT1 because it would add too much cost to the project to go with a built LS motor and I wasn't sure about the long term reliability of pushing a junkyard LQ9 that far. Now I am starting to hear of guys making 900rwhp with just mildly worked LQ9 motors, but still most threads I find on the topic regarding how far you could push them reliably are many years old and don't have any follow ups after dyno #'s are posted.
I am wondering if it would be worth it for me to ditch the built LT1 for an LQ9? With the cost of the swap, I couldn't be building a LQ stroker or anything. I'd be looking at a motor I could do oil pan to intake for maybe 3k tops. What would I need to do to an LQ motor to make and support more power than my LT1 should reliably? Reliably is key here, if I wanted a time bomb I'd just throw more boost at my LT1. If a mildly worked LQ for the budget I can do won't be an upgrade over my LT1 then it won't be worth the swap.
What do you guys think?
Last edited by kris396ss; Apr 22, 2016 at 10:22 AM.
I built a lq4 turbo and it was the best thing I did to my nova the power and street manors is second to none.
if you pick up a good engine take it apart clean it all up regap the rings and use a turbo cam and ls9 gaskets you will be good to go. we have done 2 engines in the last year like that and they are running on e85 14* timing and 15 # boost so far and they are holding up great. one is in my brothers Silverado and at 4300 lbs it runs very good no track times yet but it runs good .
mine has ben running for 3 years now but I'm only 10# boost pumpgas , it runs 10.50s at 130 mph at 3600 lbs with a 3000 ptc converter and a 3.23 gear. but I just swapped to e85 and cranked it up now that my axle can take it. new track times soon.
Everyone tells me the LQ is the way to go over the LT1 but I guess I am confused at exactly why. Not comparing stock to stock here, but a fully built LT1 with forged parts set up to handle power and a compression ratio set for boost. The only differences I can see are the following:
6 bolt mains on the LQ
better head flow on the LQ
better tuning capabilities for LS series motors
With my LT1, I'd be using a 24x conversions so the tuning really doesn't factor in. My AI heads flow just under 300cfm so I think I'd still outflow a set of stock LQ heads. If I could run a pair of L92 heads on the LQ motor though, I am sure that would be an improvement.
What do you guys think? My tuner, machinist and head porter all think I shouldn't have a problem with seeing 700rwhp out of my LT1 setup with methanol injection on pump gas. Can a mildly worked LQ for the budget of around $2500-3000 really out perform that and reliably?
so, why not find out, then make a choice??
Cam only lq4, unknown mileage or background
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For making 700rwhp, there really isn't too much to find out. I have seen first hand a few very similar setups make the same or more power, so I'm not too concerned about meeting that goal.
Bottom line though, I am almost positive the LT1 will make the 700rwhp mark I am looking for, and everything in my motor was built to handle that kind of power except maybe for the mains (straight instead of splayed).
If an LQ build within my budget can do MORE, and do it more reliably, then I might as well do it now while I can still sell a lot of my LT1 stuff as new. Not to mention I can save money on not buying some of the LT specific stuff like the 24x swap which I haven't purchased yet and the time I'd be spending welding up custom stainless turbo manifolds for my LT.
I'm at that tipping point where I'm just not convinced that a mostly stock/midly tweaked LQ that I can afford is a better choice than a fully built LT with good heads on it and forged parts. I know the LQ's are great motors, but I just don't want to go through the trouble of the swap if it isn't going to be a significant improvement in power and reliability over the built LT1.
It's kind of hard to get straight answers because so many are on the "LT's suck" bandwagon, but I have seen them first hand make some awesome power when things are done right. Obviously, if I could go back I would have sank my money into building an LQ motor up the way my 396 LT1 is built, but I can't afford to do that now so I'm torn between my built 396 LT and a cheap/mostly stock LQ.
Dburt, what's your cars weight approximately?
Last edited by kris396ss; Apr 23, 2016 at 08:09 PM.
If you were starting from scratch, then ya, use an LS engine
Reliability? I drive it every dry-weather day I have, even in the cold of winter. I'm sure you would be fine with an LQ9. Just make sure you get the 05+ engines with the floating pin rods. They're severely stronger.
I built a lq4 turbo and it was the best thing I did to my nova the power and street manors is second to none.
if you pick up a good engine take it apart clean it all up regap the rings and use a turbo cam and ls9 gaskets you will be good to go. we have done 2 engines in the last year like that and they are running on e85 14* timing and 15 # boost so far and they are holding up great. one is in my brothers Silverado and at 4300 lbs it runs very good no track times yet but it runs good .
mine has ben running for 3 years now but I'm only 10# boost pumpgas , it runs 10.50s at 130 mph at 3600 lbs with a 3000 ptc converter and a 3.23 gear. but I just swapped to e85 and cranked it up now that my axle can take it. new track times soon.







