One last chance to sway me- LT4 vs LSX build
06-08-2018, 11:37 AM
#1
One last chance to sway me- LT4 vs LSX build Alright guys, after a few months of research, phone calls to whipple and speaking back and forth with a whipple tech, speaking to various shops who have used the GM LSX B15 engine I have finally mapped out my LSX build and priced out what I believe will be about 99% of the parts I'll need to drop it in my 96 Impala SS.
The plan is to run a bone stock LSX B15 376 using a Whipple gen 3 front feed 2.9L blower. Whipple doesn't believe I'd have a problem with making 750-800WHP using that model of blower without spinning it to the point of reliability issues. I know the engine can handle it, I have spoken to multiple guys pushing the stock B15 well beyond the 800whp mark. I know the blowers are making 800+ WHP with the Coyote crowd.
When I priced out the build, I mean extensively priced it out even down to rough guesses on hardware, I realized that I'd be right in the ballpark of an LT4 connect and cruise swap with a 4l90e (and all the extras I'd require for that including HX, HX pump, oil cooler, mounts, possible oil pan swap, headers, etc...).
The B15 LSX swap would likely be much easier as LSX swaps have been done hundreds of times already in B bodies. I know what parts WILL work. It'll also make a lot more power with the whipple 2.9 than a stock LT4 or even LT4 with minor bolt ons (I think?).
Since I plan on mocking up the B15/accessories using my LM7 block this weekend and probably getting started on ordering parts, I figured this is my least chance to hear any input from guys on why I SHOULDN'T go LSX and should do LT4 instead. I'll hear anything other than just "cool factor" in having the LT4. Car hasn't run in 10 years and I really could care less about that. I just want the best bang for the buck I can get as far as power/drivability/reliability/efficiency goes. I want to build a 4300lb sled thatt can practically be used as a daily driver with big HP, comfortable on long road trips and fast. . So what advantages could a stock or mild bolt ons LT4 have over a whipple 2.9 blown LSX?
For anyone who has driven both, PD blown LSX cars and PD blown LT cars, is there anything that makes the LT a clear winner?
The plan is to run a bone stock LSX B15 376 using a Whipple gen 3 front feed 2.9L blower. Whipple doesn't believe I'd have a problem with making 750-800WHP using that model of blower without spinning it to the point of reliability issues. I know the engine can handle it, I have spoken to multiple guys pushing the stock B15 well beyond the 800whp mark. I know the blowers are making 800+ WHP with the Coyote crowd.
When I priced out the build, I mean extensively priced it out even down to rough guesses on hardware, I realized that I'd be right in the ballpark of an LT4 connect and cruise swap with a 4l90e (and all the extras I'd require for that including HX, HX pump, oil cooler, mounts, possible oil pan swap, headers, etc...).
The B15 LSX swap would likely be much easier as LSX swaps have been done hundreds of times already in B bodies. I know what parts WILL work. It'll also make a lot more power with the whipple 2.9 than a stock LT4 or even LT4 with minor bolt ons (I think?).
Since I plan on mocking up the B15/accessories using my LM7 block this weekend and probably getting started on ordering parts, I figured this is my least chance to hear any input from guys on why I SHOULDN'T go LSX and should do LT4 instead. I'll hear anything other than just "cool factor" in having the LT4. Car hasn't run in 10 years and I really could care less about that. I just want the best bang for the buck I can get as far as power/drivability/reliability/efficiency goes. I want to build a 4300lb sled thatt can practically be used as a daily driver with big HP, comfortable on long road trips and fast. . So what advantages could a stock or mild bolt ons LT4 have over a whipple 2.9 blown LSX?
For anyone who has driven both, PD blown LSX cars and PD blown LT cars, is there anything that makes the LT a clear winner?
Last edited by kris396ss; 06-08-2018 at 11:47 AM.
06-08-2018, 02:32 PM
#2
TECH Senior Member
I think the LSX is the deal for you. There isn't as much experience with the LT engines, comparatively speaking. And not as much aftermarket support for it either.
06-10-2018, 11:05 AM
#3
Thanks G Atsma, that's what I was thinking. Just seems like the reward isn't worth the cost with the LT swap. The B15 topped with a whipple, all out power wise, should way out perform even a mildly modded LT4 from what I am seeing. Lt4 seems like it makes some awesome power curves though, and I am guessing there would probably be some drivability benefits, maybe better gas mileage etc.. from the direct injection but I haven't seen anybody cite any huge differences enough to warrant the added work of the swap. Plus, it seems like I'd need full bolt ons, E85 tune or meth and a maybe cam to make the power that the B15/Whipple 2.9 could make which puts the cost well over the b15 swap.
06-20-2018, 04:49 PM
#4
Do you want different and cost/custom factor is not an issue? Go LT
Do you want ease of install/build and something more budget friendly and proven? Go LS
Your power goals are achievable on either platform honestly. The problems you will run into are fueling the LT engine (very expensive to do right now without hosing them down with methanol) and fitting it into the car (engine mounts, headers, etc would all have to be custom). If time and money are no issue, and you have a good team to help you build it or a LARGE skill set, then LT would be awesome to see in the car, but at the end of the day you'll likely be much happier with the LS with the same end result on power with a lot more time on the road and money in your pockets.
- David @ Vengeance
Do you want ease of install/build and something more budget friendly and proven? Go LS
Your power goals are achievable on either platform honestly. The problems you will run into are fueling the LT engine (very expensive to do right now without hosing them down with methanol) and fitting it into the car (engine mounts, headers, etc would all have to be custom). If time and money are no issue, and you have a good team to help you build it or a LARGE skill set, then LT would be awesome to see in the car, but at the end of the day you'll likely be much happier with the LS with the same end result on power with a lot more time on the road and money in your pockets.
- David @ Vengeance
06-21-2018, 11:02 AM
#5
Do you want different and cost/custom factor is not an issue? Go LT
Do you want ease of install/build and something more budget friendly and proven? Go LS
Your power goals are achievable on either platform honestly. The problems you will run into are fueling the LT engine (very expensive to do right now without hosing them down with methanol) and fitting it into the car (engine mounts, headers, etc would all have to be custom). If time and money are no issue, and you have a good team to help you build it or a LARGE skill set, then LT would be awesome to see in the car, but at the end of the day you'll likely be much happier with the LS with the same end result on power with a lot more time on the road and money in your pockets.
- David @ Vengeance
Do you want ease of install/build and something more budget friendly and proven? Go LS
Your power goals are achievable on either platform honestly. The problems you will run into are fueling the LT engine (very expensive to do right now without hosing them down with methanol) and fitting it into the car (engine mounts, headers, etc would all have to be custom). If time and money are no issue, and you have a good team to help you build it or a LARGE skill set, then LT would be awesome to see in the car, but at the end of the day you'll likely be much happier with the LS with the same end result on power with a lot more time on the road and money in your pockets.
- David @ Vengeance
My whole goal for this car, after having it apart in a tent for 10 years, is to have something I can enjoy with as little trouble as possible. I know it's a tall order, but I am looking to build something with the reliability/drivability of a new car and all the power of a modded hellcat or ZL1 so that I can keep up. I'm only after the easiest/most effective way of getting there, I could care less about the coolness factor. Budget is always an issue, and if one way would yield some significant benefits in drivability/reliability/power then the extra money/time would be worth it, but from what I have seen so far it doesn't appear that an LT4 would provide that to any significant degree over a built up LSX like the B15 with a 2.9 Whipple.
Mind if I shoot you a PM? I actually had some questions regarding bringing the car to you guys for tuning and a question on the whipple 2.9 setups if you have seen them at all on LS builds. .
06-21-2018, 04:01 PM
#6
Well I couldn't have heard that from a more trusted source LOL Budget friendly (if that's not an oxymoron in a forced induction build) and proven is definitely my goal here. I love welding/fabrication work but I have a project car for that. This car used to be my daily and I would love to get it running again for fall.
My whole goal for this car, after having it apart in a tent for 10 years, is to have something I can enjoy with as little trouble as possible. I know it's a tall order, but I am looking to build something with the reliability/drivability of a new car and all the power of a modded hellcat or ZL1 so that I can keep up. I'm only after the easiest/most effective way of getting there, I could care less about the coolness factor. Budget is always an issue, and if one way would yield some significant benefits in drivability/reliability/power then the extra money/time would be worth it, but from what I have seen so far it doesn't appear that an LT4 would provide that to any significant degree over a built up LSX like the B15 with a 2.9 Whipple.
Mind if I shoot you a PM? I actually had some questions regarding bringing the car to you guys for tuning and a question on the whipple 2.9 setups if you have seen them at all on LS builds. .
My whole goal for this car, after having it apart in a tent for 10 years, is to have something I can enjoy with as little trouble as possible. I know it's a tall order, but I am looking to build something with the reliability/drivability of a new car and all the power of a modded hellcat or ZL1 so that I can keep up. I'm only after the easiest/most effective way of getting there, I could care less about the coolness factor. Budget is always an issue, and if one way would yield some significant benefits in drivability/reliability/power then the extra money/time would be worth it, but from what I have seen so far it doesn't appear that an LT4 would provide that to any significant degree over a built up LSX like the B15 with a 2.9 Whipple.
Mind if I shoot you a PM? I actually had some questions regarding bringing the car to you guys for tuning and a question on the whipple 2.9 setups if you have seen them at all on LS builds. .
Not at all shoot me an email at David@VengeanceRacing.net and I will be more than happy to discuss it with you.
Regards,
David @ Vengeance