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They are, after all, air pumps. The more air through - the more HP. More RPM=more air. I'm gonna fudge the numbers a bit to make the point -- but I'm not fudging them much. Back when the F1 cars were running naturally aspirated V10s - 3.0L - they revved to about 18,000-19,000 rpm and made 800-850HP. At the same time, NASCAR motors were just a hair under 6.0L (about twice the F1 motor) - they revved to 9000-9500 rpm (about 1/2 the rpm).....and made 800-850HP. 1/2 the size + twice the rpm = same power. 'Course, doesn't really work for OEM/street cars - but for all out race motors, you can see how the math works. Of course, torque characteristics are ENTIRELY different....
Even with a box stock LS3, this car is going to be lots of fun. 450ish HP & lb-ft in a 3000 lb mid-engine package that has all the rigidity, suspension and brakes to utilize it. Nuthin' but fun.
They are, after all, air pumps. The more air through - the more HP. More RPM=more air. I'm gonna fudge the numbers a bit to make the point -- but I'm not fudging them much. Back when the F1 cars were running naturally aspirated V10s - 3.0L - they revved to about 18,000-19,000 rpm and made 800-850HP. At the same time, NASCAR motors were just a hair under 6.0L (about twice the F1 motor) - they revved to 9000-9500 rpm (about 1/2 the rpm).....and made 800-850HP. 1/2 the size + twice the rpm = same power. 'Course, doesn't really work for OEM/street cars - but for all out race motors, you can see how the math works. Of course, torque characteristics are ENTIRELY different....
Even with a box stock LS3, this car is going to be lots of fun. 450ish HP & lb-ft in a 3000 lb mid-engine package that has all the rigidity, suspension and brakes to utilize it. Nuthin' but fun.
You can guarantee that the F1 guys wouldn't have been spinning the engine near that high, if they didn't have to because displacement was limited by rules
2014+ 4.3 V6 with twins.. Just sayin,, someone has to do it..
Stock its near 300HP.. Should hold up to similar abuse that the V8's get..
similar weight and what not to the Porsche motor for about 20K less..
Thank you for all your input, I don't know - what I don't know.
I have built 2 one being a high-end car Porsche 914 , SBC and LS cars. I'm hoping to put all
the belt driven systems on the passenger side. Get a carbon type seat keeping it thin.
Here are my two gone but beloved 914"s.
SBC 930 4 speed with a Jetta PS rack and a Toyota MR2 electric pump and Ferrari 575 mufflers / with cutout valves
I did all the easy stuff on this one a very very skilled
guy did the incredible fabrication work.
Awesome to see another Porsche LS swap! I'm currently swapping my 996 with a LS1. Pulling the M96 out pretty soon and I have the LS1 together. My adapter is from Eric at A&E and should be here soon too. I'm going with the Holley Terminator X package and LS3 water pump. I am also using the ICT alternator mount for the lower passenger side (when in the P car). I also plan to use the driver's side AC mini pump. I deleted the power steering for now but I may switch that to a MR2 or GT3 pump.
How did the exhaust sound with the Ferrari mufflers? I am looking at doing 180 degree headers since I want the typical exotic Porsche sound out of the V8. I know it won't be exactly like the original sound at all, but I want something different and higher pitched with an exotic feel to it. I bought my motor mount kit from Stuttgart Muscle but I wouldn't hesitate to make a set. I just wanted to keep things easy for this swap and he has great prices, tech, and options for the LS swapped Porsche. I'm stoked to see your progress! The LS3 should kick *** with a good cam and tune.
Your wrong... so very wrong. Almost every actually fast LS revs out to make power, not many if any of the guys running 7's or faster shift at 6500. Even the guys running 8's with SBE rev them out past 7k RPM.
I was speaking from more of a street driving viewpoint. LS engines CAN rev better than most other V8's, but not all of them NEED to. 6.2's in particular.
Also speaking in relation to Porsche engines, which have NO low end power compared to LS's or most other V8 engines.
I DO see your point though.
SLOW SEDAN - we're talking about a mild street LS -- not a car that run's 7's or 8's -- yes, those are going to be built to rev higher. And it’s “you’re” wrong, not “your”.
And - just to further ventilate the point -- the Porsche engine in question is a 3.4L flat six that makes between 325 and 340HP in naturally aspirated trim. The reason that they don't make near as much torque or power as the V8's in question is because of the displacement difference. Some of that difference is because of the Porsche engine revving higher and some is because it's in a higher state of tune than the LS's in question. To me the comparable GM motor would be one of the 5.3's that makes around 325HP in factory trim. It makes it 1500--2000 rpm lower than the Porsche engine does. 275 torque and 325HP out of 3.4L without a booster is damned respectable. But it ain't gonna compete with a 6.2L (almost twice the displacement) at 430/424....unless you build the little 6 to still be breathing up around 8500-9000 rpm. And we're back to air-pump basic math.
Last edited by Michael Yount; 04-26-2019 at 04:16 PM.
I had no issues revving my LS7 to 7000rpm.... but there really isn't a point to even rev it that high unless drag racing since it made soo much torque everywhere... I've had LS1 (440rwp) all the way to 440ci stroker setups (595rwhp).... and I would give up rev's for more torque any day of the week. An extra 50+ cubic inches does wonders on the street/road course due to one word.... TORQUE.
Remember also that higher rev's beyond about 7500rpm really must have a dry sump oiling system... you should also have Ti valves in the heads.... need an intake manifold that can actually support over 7000rpm's..... plus engines just wear out quicker with stupid high revs.
Unless you have to fit into a racing class... run the big cubes. The stress from 1/8 and 1/4 mile racing doesn't really compare to 20-30 minute road racing punishment especially with heat management. HPR is doing big stroke.... LS motors that are pretty reasonably priced. https://horsepower-research.com/prod...uminum-442-ls3 Personally I don't really want a motor over 4" stroke due to piston sideloading.... but I'm guessing Eric Koenig (HPR main guy) knows otherwise from lots of experience building LS engines for 15+ years and teaching at SAM. They probably refresh these motors every year.... but probably worth a phone call to them!
I'll run future posts through my legal department. Maybe show it to a focus group or two before posting.
It all is in the "basic" knowledge category. speaking off the cuff and not under oath for sure
I'm still waiting for parts !!
I'll run future posts through my legal department. Maybe show it to a focus group or two before posting.
It all is in the "basic" knowledge category. speaking off the cuff and not under oath for sure
I'm still waiting for parts !!
Originally Posted by gtxracer
Awesome to see another Porsche LS swap! I'm currently swapping my 996 with a LS1. Pulling the M96 out pretty soon and I have the LS1 together. My adapter is from Eric at A&E and should be here soon too. I'm going with the Holley Terminator X package and LS3 water pump. I am also using the ICT alternator mount for the lower passenger side (when in the P car). I also plan to use the driver's side AC mini pump. I deleted the power steering for now but I may switch that to a MR2 or GT3 pump.
How did the exhaust sound with the Ferrari mufflers? I am looking at doing 180 degree headers since I want the typical exotic Porsche sound out of the V8. I know it won't be exactly like the original sound at all, but I want something different and higher pitched with an exotic feel to it. I bought my motor mount kit from Stuttgart Muscle but I wouldn't hesitate to make a set. I just wanted to keep things easy for this swap and he has great prices, tech, and options for the LS swapped Porsche. I'm stoked to see your progress! The LS3 should kick *** with a good cam and tune.
Don't mind some of the riff raff I'm still interested in hearing how you liked the Ferrari exhaust on your last P car!
6.2 LS3's as well as the 5th gen LT's rev exceptionally well so not sure why you wouldn't want to, besides just being scared of doing it.
They DO rev very well, and will live at up to around 6500rpm fairly consistently. My point is, in a situation where it replaces an engine that NEEDED to rev that high to make power, it does NOT NEED to. The LS makes far more power at lower revs, and that can and should be taken advantage of. The life of an LS constantly revved to 6000-6500 most of its life will lead a much shorter life than otherwise. It's not about fear, just engine life.
The Ferrari was a Maranello 575 front engine car so being a SBC I used them to quiet the car down a bit. It had some very nice cut-outs/two tone vacuum
controlled tips. Look like an LS3 is going to be my choice.
Any sound clips of the Ferrari mufflered V8? I run OEM Coyote 5.0L mufflers on the LS3 in mine. Quieter than the aftermarket stuff....but a nice "metallic" bite when you get into it. Of course, intake sound contributes a great deal to the sound experienced inside the car.
Apparently stock and mild don't mean what I think they mean. And the OP's platform isn't as light as I'm guessing you think it is....
I thought they were about 2,900-3000lbs. When a 4,600lb truck or 4,000lb car can run mid 9's with a stock 4.8L or 5.3L then I think a two door Porsche coupe is lightweight.
I referenced 3000# in my earlier post guys. But to get 9’s (even high 9’s) with a stock 325hp 5.3 you need to be about 1600 lbs. How are stock 4600 lb SUV’s running 9’s? What am I missing?
04-23-2019, 04:26 PM
As mentioned before -- rpm sounds fantastic, but lord is it expensive. 
