Supercharged Ls V8

[rocket5979]

Quik, are the Marauder engines that much stronger than the newer LS? I was just curious as they are only rated at 302HP and with SC get in the 450 RWHP range with moderate boost. I would also think the rear differential would be a limiting factor as well in the LS.

They aren't neccessarily stronger in construction, but they do come from the factory with less compression which is more boost friendly and they also have more displacement too which helps. The aftermarket for the SOHC 2V and DOHC 4V 4.6's is tons more than the DOHC 3.9 LS engine which has ZERO aftermarket.

You could rebuild a modular 4.6 to hold 550rwhp for $2,000 no problem with a new forged rotating assembly. If you were to build the LS engine the custom billet connecting rods alone would cost MUCH more than that.

The main weaknesses in the LS's powertrain and drivetrain in order would be:

Tranny
Engine rotating assy. (due to high comp if boosted)
Rear Diff
Rear halfshafts / hubspline
Wheel studs

The last two items would only occur under higher power levels (500+rwhp).

 

[Putter-GLHT]

I guess the rubber U-joints were proven 10 years ago as not a weak link by the XR4Ti people, although those IRS like to gernade too... (They are an 8" also are they not?)

 

[2001LS8Sport]

You could rebuild a modular 4.6 to hold 550rwhp for $2,000 no problem with a new forged rotating assembly. If you were to build the LS engine the custom billet connecting rods alone would cost MUCH more than that.

Good point.

There are MANY engine builders who swear the short block for our 03/04 Cobras will handle a 1000 hp....stock right from the factory. However, piston clearances are so tight (.001") that you really need to open them up a couple of thousands to be safe. But other than the occasional piston grabbing due to the clearance issue, there are a lot of very high hp Cobras running around just fine. It's all in the tune.

 

[rocket5979]

Good point.

There are MANY engine builders who swear the short block for our 03/04 Cobras will handle a 1000 hp....stock right from the factory. However, piston clearances are so tight (.001") that you really need to open them up a couple of thousands to be safe. But other than the occasional piston grabbing due to the clearance issue, there are a lot of very high hp Cobras running around just fine. It's all in the tune.

Yeah, those engine builders exaggerated a little. The 03/04 Cobra engines are truly badass (in the same league as the 2JZE Supra engines) and really strong but now that they have been out for a few years we have seen testing and failure points on the stock bottom ends. I would feel safe going to 650rwhp eddie current dynotuned on a twin screw, detuned water/meth combo, but I would always feel like I am running on borrowed time at any power level above that.

Now any other stock DOHC 4.6 bottom end (higher comp & crappy rods) I would treat like a fragile egg at anything around 500rwhp on a twin screw blower. Some fail at even lower power levels than those because while the Cobra cranks may be forged, the rods & pistons in the old gen Cobra's weren't.

Being that I dont want to try to afford yet another big supercharger project I believe I will go with the power adder that the LS naturally likes, which is the juice. A 75 dry shot sounds ok to me. Nothing too extreme to cause any damage and I can turn it off when others drive it. In the long run nitrous will be more expensive, but I'm ok with that. I will save the bigger LS power numbers to the crowd (Quik & crew) with more money remaining in their wallets, as I am about tapped out with my current car project.

 

[PM80]

So if everything goes well tomorrow and idea on how long we might be looking at to get the first production one out there?

I know one step at a time, but I want one yesterday. lol

 

[Quik LS]

not dynoing until I get the front-mount intercooling installed - that will take at least this weekend..... I'll post more pics.

 

[eL eS]

oh the agony of waiting and it isnt even my car.

 

[mikerc]

Very nice.

 

[StinkinLinkinLS01]

Being that I dont want to try to afford yet another big supercharger project I believe I will go with the power adder that the LS naturally likes, which is the juice. A 75 dry shot sounds ok to me. Nothing too extreme to cause any damage and I can turn it off when others drive it. In the long run nitrous will be more expensive, but I'm ok with that. I will save the bigger LS power numbers to the crowd (Quik & crew) with more money remaining in their wallets, as I am about tapped out with my current car project.

You mentioned running a 75 DRY shot. I was planning on running a 75 WET shot. I was just about to purchase a 35-125 uni ford EFI Nitrous Express WET kit for my 2001 V8LS with 85K miles but I would like a little more input first. First and foremost I want to make sure I dont blow my motor. Of course the nos guys tell me my engine will be just fine running a 75 WET shot but then again they said my car could handle a supercharger on top of the nos and I'm not so sure of that. Obviously you prefer the dry-kit, I just wanted to know why you would choose that over the wet kit and what you (or anyone else) recommend in regards to the following:

- brand (if you think it matters, I was going with NX as others have)
- usage (frequency, WOT vs. push-button, rpm range, etc)
- accessories (heaters, purge kits, etc)

Most importantly I want long lasting performance with little or no nitrous related problems to the engine. I know alot of this depends on how you use it, and I'm fairly confident I'll be easy on her. I live in MN so I am only planning to spray on the weekends maybe 3 or 4 months out of the year. Thanks in advance.

p.s. What about detection by the dealership if I do fry a piston or something? My buddy who also runs nos on his V6 firebird - also under waranty - told me all I need is an oil change and nos is almost undetectable. Another guy told me a mechanic could tell the second he opened up the engine. Which is more correct? Thanks.

p.s.s. Up until now it looked like this guy had the optimum setup, only maybe with a 75 shot. Check it out:

http://forums.llsoc.com/index.php?showtopic=11514

 

[Iancusp]

dry all the way

 

[Quik LS]

I used a Nitrous Express Part # 20922 (wet) kit for almost a year. Ran 100shot a couple of times.

With a wet shot - you worry about fuel pooling and no2 mixing with that...
With a dry shot - you worry about the stock fuel pump keeping up and running lean


I went wet because it was long before the SCT reprogramer was available - so we had no chance of remapping the fuel curve or injector cycle - so I could never be sure I would not run lean.

 

[zexls]

I run a 100hp shot on my 2000. I run the wet shot with a air/fuel gauge. No problems.

 

[Quik LS]

I run a 100hp shot on my 2000. I run the wet shot with a air/fuel gauge. No problems.

any 1/4 mile times or dyno numbers?

 

[zexls]

No not yet, the nearest track is 2hr away and I just got the sct Tue. The dyno is the next step. The only thing is that I am realy protective of my car and I dont let just any one in my car.

 

[rocket5979]

You mentioned running a 75 DRY shot. I was planning on running a 75 WET shot. I was just about to purchase a 35-125 uni ford EFI Nitrous Express WET kit for my 2001 V8LS with 85K miles but I would like a little more input first. First and foremost I want to make sure I dont blow my motor. Of course the nos guys tell me my engine will be just fine running a 75 WET shot but then again they said my car could handle a supercharger on top of the nos and I'm not so sure of that. Obviously you prefer the dry-kit, I just wanted to know why you would choose that over the wet kit and what you (or anyone else) recommend in regards to the following:

- brand (if you think it matters, I was going with NX as others have)
- usage (frequency, WOT vs. push-button, rpm range, etc)
- accessories (heaters, purge kits, etc)

Most importantly I want long lasting performance with little or no nitrous related problems to the engine. I know alot of this depends on how you use it, and I'm fairly confident I'll be easy on her. I live in MN so I am only planning to spray on the weekends maybe 3 or 4 months out of the year. Thanks in advance.

p.s. What about detection by the dealership if I do fry a piston or something? My buddy who also runs nos on his V6 firebird - also under waranty - told me all I need is an oil change and nos is almost undetectable. Another guy told me a mechanic could tell the second he opened up the engine. Which is more correct? Thanks.

p.s.s. Up until now it looked like this guy had the optimum setup, only maybe with a 75 shot. Check it out:

http://forums.llsoc.com/index.php?showtopic=11514

Brand doesn't matter much. There will be praise and horror stories for every brand out there. Having a WOT and RPM window switch along with a bottle heater are some nice things to have to keep things safe. That way you know it will only spary while WOT and only during (for instance) a 3,000-6,250 rpm run. The bottle heater is to keep bottle pressure regulated through keeping the bottle temp regulated. The colder the bottle, the less nitrous your actually injecting due to less bottle pressure. If you want, you can also program and hook up an LC-1 wideband or other wideband to activate your nitrous system only during certain A/F ratios also so that you never run a chance of running lean while spraying.

I prefer the dry shot because it is easier to tune for and no pooling in the intake like Quik mentioned. Wet kits are great for bigger nitrous shot applications where you need more tunability within a certain system but the dry shot is just simpler to mess with. Running such a low shot on a stock engine in good form is pretty simple to do. However, running dual PA's (nitrous and charger) is asking for LOTS of trouble on most any stock bottom end on a vehicle, let alone the tranny and other components! Whoever you talked to that said those comments I would stay FAR away from as they don't know a thing about performance and safe limitations of drivetrain parts.

With a musclecar and a blown engine the dealer opens the engine looking for signs of mods causing the problem. With our vehicles, being that they are viewed very differently from typical musclecars, they don't get as keen an eye looking the engine over if it were to blow after nitrous becuase LS's aren't popular musclecars. hehe. If they even did notice what looked like damage from nitrous usage, they would be so suspect about their findings that they would probably doubt themselves into not believing their own data.

Whenever I take my LS to the dealer I always de-mod it all the way and reprogram back to stock so that when they do take a look-see all they see is a stock vehicle. Keeps things simpler in the future if something does go awry and I am trying to get it covered.

 

[StinkinLinkinLS01]

So with all things considered and all necessary accessories:

- purge kit
- WOT/RPM switch
- bottle heater
- proper usage
- no more than 75-100 shot

Which is more dangerous and/or more likely to occur -- fuel pooling with a wet kit or running lean with a dry kit?

 

[2001LS8Sport]

So with all things considered and all necessary accessories:

- purge kit
- WOT/RPM switch
- bottle heater
- proper usage
- no more than 75-100 shot

Which is more dangerous and/or more likely to occur -- fuel pooling with a wet kit or running lean with a dry kit?

I have seen some HORRIBLE nitrous explosions with wet kits...blows the manifold clear off the car. That's what can happen with puddling, etc. It's rare...but I've seen it. It's even rarer with a dry kit...and with the availability to tune for it with the SCT now, it makes no sense to add the extra expense and work involved to go wet. However, you need to make sure you have the fuel capablities and injector size to keep from going lean. With a small shot, you're probably ok...but the only way to know for sure is to toss it on a dyno and have the a/f ratio checked and make sure your MAF sensor isn't maxing out. Just MHO......

 

[rocket5979]

I have seen some HORRIBLE nitrous explosions with wet kits...blows the manifold clear off the car. That's what can happen with puddling, etc. It's rare...but I've seen it. It's even rarer with a dry kit...and with the availability to tune for it with the SCT now, it makes no sense to add the extra expense and work involved to go wet. However, you need to make sure you have the fuel capablities and injector size to keep from going lean. With a small shot, you're probably ok...but the only way to know for sure is to toss it on a dyno and have the a/f ratio checked and make sure your MAF sensor isn't maxing out. Just MHO......

Well said... +1...

 

[Quik LS]

I run a 100hp shot on my 2000. I run the wet shot with a air/fuel gauge. No problems.

I'm confused by this statement - you say you run a 100shot with no problems - but then you say you haven't been tuned yet.....

Have you really ran it yet on 100shot?

 

[rocket5979]

I'm confused by this statement - you say you run a 100shot with no problems - but then you say you haven't been tuned yet.....

Have you really ran it yet on 100shot?

Maybe he is tuned by magic.
















abacadabra!

 

[MrWilson]

You could rebuild a modular 4.6 to hold 550rwhp for $2,000 no problem with a new forged rotating assembly. ).

WHAT!? FROM WHERE! i cant figgure out a way to rebuild one for less than 6k

 

[rocket5979]

WHAT!? FROM WHERE! i cant figgure out a way to rebuild one for less than 6k

HOLY GOD! Dude I have a fully built billet racing shortblock that will hold 1000+ horsepower for $4,550 from VT Engines out of Lansing MI. For a little over $6,000 I could get a full longblock capable of withstanding 750rwhp! I don't know where you got quoted from, but that price is SUPER high. Talk to Modular Powerhouse, VT Engines, or Modular Depot for having a 4.6 built for you. I am having my 4.6 billet SB built by VT because they turn out one mean product and stand behind it 110%. If you were to get the built rotating assembly itself and do your own install the price would drop significantly from the $4,550 I mentioned above. That was a billet racing engine I was talking about, a forged one will be much cheaper.

 

[MrWilson]

HOLY GOD! Dude I have a fully built billet racing shortblock that will hold 1000+ horsepower for $4,550 from VT Engines out of Lansing MI. For a little over $6,000 I could get a full longblock capable of withstanding 750rwhp! I don't know where you got quoted from, but that price is SUPER high. Talk to Modular Powerhouse, VT Engines, or Modular Depot for having a 4.6 built for you. I am having my 4.6 billet SB built by VT because they turn out one mean product and stand behind it 110%. If you were to get the built rotating assembly itself and do your own install the price would drop significantly from the $4,550 I mentioned above. That was a billet racing engine I was talking about, a forged one will be much cheaper.

right...shortblock...4550....now, lets talk longblocks.

 

[rocket5979]

right...shortblock...4550....now, lets talk longblocks.

That $4,550 amount was for a billet racing shortblock, not exactly your run of the mill SB. A regular SB (forged, not billet) capable of withstanding 600 or so hp will cost about $1,800 less. You wont need to get new heads unless the ones you have now are really messed up. Much much easier and less money involved in just having your current ones reworked and swap the cams out along with the springs and maybe the valves/guides and whatnot.

What my $2,000 amount was if you just get the forged rotating assembly and install it into your existing block yourself. Not too hard and kind of fun.

No real reason to go with a full longblock unless your existing heads are shot and you want to pay the high premium for it all.

 

[MrWilson]

That $4,550 amount was for a billet racing shortblock, not exactly your run of the mill SB. A regular SB (forged, not billet) capable of withstanding 600 or so hp will cost about $1,800 less. You wont need to get new heads unless the ones you have now are really messed up. Much much easier and less money involved in just having your current ones reworked and swap the cams out along with the springs and maybe the valves/guides and whatnot.

What my $2,000 amount was if you just get the forged rotating assembly and install it into your existing block yourself. Not too hard and kind of fun.

No real reason to go with a full longblock unless your existing heads are shot and you want to pay the high premium for it all.

oh yea, i know what your talkin bout....but seeing how the mark is runnin the B heads...it kinda makes it hard to bolt other intakes(specially the s/c) so id need heads and all too...longblock is a better option for me.

i checked out vt...their shortblock is $3495...i can get a longblock with the s/c for $3750 from my ford dealer...dont ask how, price is for me alone.