V8 or turbo 4?
10-11-2019 | 09:50 PM
#21
I can't tell if I'm down a cylinder in my V8. If that's a good or a bad thing, I don't know.
I'm only running 205 rubber, and learning throttle control is huge. The car goes from being an exercise in inertia management to "on off on" throttle reaction. I still need more seat time to be smooth - but it doesn't quite drive like a miata anymore. And no, it's not weight - it's torque.
And I'll bring this up - I've been turbo'd at 260, we have the LFX that is 325hp at the crank, and my LS3 which is 425hp at the crank. The LFX still retains stock-like driveability with predictable power - on 205's you can wring it without expecting the rear to step out unless commanded. I'm still scaring myself with the LS3. I expect I'll get better. I will state that the getrag is superior to the torsen - you can feel it work.
I'm only running 205 rubber, and learning throttle control is huge. The car goes from being an exercise in inertia management to "on off on" throttle reaction. I still need more seat time to be smooth - but it doesn't quite drive like a miata anymore. And no, it's not weight - it's torque.
And I'll bring this up - I've been turbo'd at 260, we have the LFX that is 325hp at the crank, and my LS3 which is 425hp at the crank. The LFX still retains stock-like driveability with predictable power - on 205's you can wring it without expecting the rear to step out unless commanded. I'm still scaring myself with the LS3. I expect I'll get better. I will state that the getrag is superior to the torsen - you can feel it work.
LS aluminum blocks are everywhere but I haven't been able to find a good source for the LFX
Reply
0
0
10-11-2019 | 10:02 PM
#22
Senior Member
Joined: May 2007
Posts: 997
Total Cats: 156
From: Atlanta
car-part.com, lkq - I mentioned how to search in the portabull LFX build thread. The downside is yes, you need a Camaro engine to start since it'll have all the accessories and brackets in the right place - buy once, cry once. If we do ever blow it up, we'll snag a Impala/LaCrosse/CTS/SRX/Caprice/Colorado/Equinox block and swap the accessories across.
But don't underestimate the fabrication skills it takes for any swap. As much as there are kit components for a lot of things, expect that much of everything will need some tweaking to get right - and even better if you can make your own brackets etc.
But don't underestimate the fabrication skills it takes for any swap. As much as there are kit components for a lot of things, expect that much of everything will need some tweaking to get right - and even better if you can make your own brackets etc.
Reply
0
0
10-13-2019 | 08:14 AM
#26
Post a dyno plot, for reference.
Other dyno plots I've seen were lower, but there are different versions of the engine so that is plausible.
A fellow with a LFX Miata came and found me at Road Atlanta to ask what I had under the hood after I passed him on the back straight. There was a significant difference in speed.
I'm partial to turbos.
A 600cc bump in displacement and a good breathing head that come with a K swap sound like a win.
Other dyno plots I've seen were lower, but there are different versions of the engine so that is plausible.
A fellow with a LFX Miata came and found me at Road Atlanta to ask what I had under the hood after I passed him on the back straight. There was a significant difference in speed.
I'm partial to turbos.
A 600cc bump in displacement and a good breathing head that come with a K swap sound like a win.
Reply
0
0
10-13-2019 | 09:47 AM
#27
Junior Member
Joined: Nov 2017
Posts: 45
Total Cats: -1
From: Ambler, PA
I'm currently rebuilding my LS1 when I wasted some bearings on track. Luckily I was able to rehone and save the block. Before that I tried the usual sources, ebay, craigslist, ls1tech forums, facebook marketplace, and I wouldn't have said they were plentiful. Most of the ones I did see all came with the caveat that they were pulled when the engine made some terrible noises. There was a good one on ebay. Or get a junkyard motor and hope it's not trash. New LS2 GM Performance blocks are $1400 and come ready to bolt stuff on, but I hope that's not where were headed as far as availability of bare LS alum blocks.
Reply
0
0
10-13-2019 | 05:44 PM
#29
Senior Member
Joined: May 2017
Posts: 1,119
Total Cats: 166
From: Austin, TX
I'm really interested in the LFX swap and I'd ******* love to have that integral exhaust manifold and a perfect bolt on 6 speed that doesn't need any stupid adapters and weird flywheel combos, but I wasn't sure about where I'd even source a v6 Camaro engine.
LS aluminum blocks are everywhere but I haven't been able to find a good source for the LFX
LS aluminum blocks are everywhere but I haven't been able to find a good source for the LFX
Reply
0
0
10-17-2019 | 08:01 PM
#33
Newb
Joined: Oct 2019
Posts: 9
Total Cats: 1
From: Atlanta Georgia
I have had two V8s, both ford 5.0L based......one naturally aspirated and one vortech supercharged. The Naturally aspirated version made 310 whp and 330 wtq. The vortech supercharged combo made 468whp and 430wtq. They were both awesome and I loved them. I now have a built 1.8 with a gt2876R at 28lbs on 93 pump gas. The motor is 8.5:1 CR to handle the high boost and it makes 345whp with neutered timing. I beat the snot out of it constently and it has been dead reliable to date. All 3 cars were used as daily drivers at least 3-4 days a week.
In my opinion, you can't go wrong either way.....the v8 route or the turbo 4cyl variant. Personally, I like the current 4cyl turbo combo the best of all. At 345whp it feels as fast as the supercharged v8 combo I had (although it's likely not). The lightness of the 4cyl turbo combo just feels drastically different to me. The lighter weight with even the lower 345whp feels very very quick. In my opinion, the ~350whp level is near perfection for my taste.
It also depends on your intended purpose for the car. Whenever I build a car or give advice to folks about to embark on a build, I always ask two questions.....what do you intend to do with the car and what tire will you run on. From there, I build the entire combination around those two answers....
Ultimately, it comes down to what YOU like best, but my vote is some variant of a 4cyl turbo combo that can reliably make ~350 whp....
In my opinion, you can't go wrong either way.....the v8 route or the turbo 4cyl variant. Personally, I like the current 4cyl turbo combo the best of all. At 345whp it feels as fast as the supercharged v8 combo I had (although it's likely not). The lightness of the 4cyl turbo combo just feels drastically different to me. The lighter weight with even the lower 345whp feels very very quick. In my opinion, the ~350whp level is near perfection for my taste.
It also depends on your intended purpose for the car. Whenever I build a car or give advice to folks about to embark on a build, I always ask two questions.....what do you intend to do with the car and what tire will you run on. From there, I build the entire combination around those two answers....
Ultimately, it comes down to what YOU like best, but my vote is some variant of a 4cyl turbo combo that can reliably make ~350 whp....
Reply
0
0
Thread
Thread Starter
Forum
Replies
Last Post
Tyreshredder
General Miata Chat
8
04-29-2012 11:47 AM
