EFI SBC vs LS Motor

[redefined]

Are all of you guys asking about EFI options using this on SBC/BBC? Or are some of you using it on LS applications?

So far everyone has told me to just go LS.

[Ron Sutton]

Originally Posted by redefined

Are all of you guys asking about EFI options using this on SBC/BBC? Or are some of you using it on LS applications?

So far everyone has told me to just go LS.

I can't speak for Bryan or Don, but I was asking in general about the EFI units themselves. You sound like you're deciding between SBC or LS, but going EFI either way.

The current street & track engine package I plan to use & offer for sale is a carbureted 410" SBC that makes 600#/730 hp.

Later in 2014 I'm developing some killer 850+ HP Normally Aspirated LS engines. I wanted to see how the FAST 2.0 is working out ... and if the complaints I hear are factual ... and if so, then what are the better EFI systems.

From what Mark shared with us, it sounds like the FAST 2.0 system is not as tailorable, and therefore doesn't offer the improved street drive-ability that is the key reason for going EFI in the first place.

We can build the same power numbers with a carb. But a carb is impossible to get optimized at each level of the rpm range. The EFI systems are capable of optimizing the fule & spark curve ... and therefore improve the lower rpm drive-ability of any engine. But it sounds like ... at this point of product development ... that some brands do this better & some not so good.

Have you decided SBC or LS yet ?

[Ron Sutton]

Originally Posted by redefined

So far everyone has told me to just go LS.

If your goal is to build 700hp with a supercharger, you can do that pretty easy with a SBC or LS. If you have a SBC that is capable of living & thriving with 700 hp, then that will be a less expensive route.

If you're building from scratch, with a 700 hp goal for each, If you did everything the same, the LS will cost a bit more. The larger additional costs you'll run into is if you're doing a change over & need to change everything in the car.

On a side note ...
700 hp with a blower is an interesting territory for most production engines. You can make factory parts work, but the life is shortened. How much depends on many specifics.

For example, you can use an LS1-7 aluminum block, but they weren't designed for that kind of power & heat, and eventually you'll have issues. But an LSA or LS9 block would work well long term. The same concept applies to cranks, rods, pistons, etc, even more so.

[carbuff]

I've used a FAST system on an SBC and a Holley HP EFI system on an LS motor. I definitely like the Holley system better, but I'm not an expert at tuning for certain. It was very easy to setup and get running smoothly, and I like the graphing / logging capabilities of the unit as well.

[supremeefi]

Better stuff out there.

As mentioned, download the software then look for available tables that will enhance drivability from cold start to hot running.

[redefined]

Ron, my current SBC motor/tranny build is in the first post. I believe the compression is around 10:1 so not sure it'd do very well boosted. I did not build the motor myself but that's what I was told. That and I don't really have anything against carbs, I just want the reliability and consistency that seems to come with fuel injection. This is the first car/motor I've ever owned that's carbed. I need to start with having it tuned correctly, both the carb and the motor.

Have I decided LS or SBC? I'd really like to do LS, but again I have nothing against SBC. Have I decided 100% fuel injection? I suppose the answer is no. I have a friend that runs a carbed LS motor in his Panoz race car and that seems to run like a scolded monkey and cranks after 2 pumps of the gas EVERY time, mine doesn't even do that.

Like I said previously also, 700hp isn't a must have. I'm not chasing a whp, a 1/4 time or anything like that. Someone had ask me a goal so that's what I threw out. More of a goal is reliability for the street, road course, autocross, than power numbers. I'd rather have 550whp and have it turn over 100% of the time I turn the key. I'd also rather not smell like exhaust/fuel every time I drive it haha!

[redefined]

For what it's worth, originally I just wanted to do a Procharged intercooled setup on the current SBC and stay carbd. Not sure how good that'd be with the current SBC build.

[WSSix]

Keeping boost at 5-6 psi and tuned properly, the Pro-charged setup will do fine with that compression ratio. That's basically the set up that Pro-Charger sells as kits for factory LT1 and LS vehicles. Now is your cam compatible with boost? That would be something to investigate.

Deadnuts reliable and cheap but make good power? Get a Gen3 6.0. Stroke it to 402 cubic inches with a 4 inch crank. Put stock or ported L92/LS3 heads on it with a cam that will produce broad power but not be radical. You should be upper 400s to 500 at the wheels with a great and very fun to drive torque band. Hell, save money and stay with Gen 3 heads. It's not like ported LS6 heads are crappy or don't make power. I'm fairly certain this is the route I'll take.

[redefined]

Originally Posted by WSSix

Keeping boost at 5-6 psi and tuned properly, the Pro-charged setup will do fine with that compression ratio. That's basically the set up that Pro-Charger sells as kits for factory LT1 and LS vehicles. Now is your cam compatible with boost? That would be something to investigate.

Deadnuts reliable and cheap but make good power? Get a Gen3 6.0. Stroke it to 402 cubic inches with a 4 inch crank. Put stock or ported L92/LS3 heads on it with a cam that will produce broad power but not be radical. You should be upper 400s to 500 at the wheels with a great and very fun to drive torque band. Hell, save money and stay with Gen 3 heads. It's not like ported LS6 heads are crappy or don't make power. I'm fairly certain this is the route I'll take.

Right but what kinda power with 5-6psi? At that level of boost is it really worth it? Not worried about the cam, if it's not good I don't mind swapping out cams but is it good for it? Probably not but not sure.

Also what would the best way to simply change the compression on my motor? BMW guys use different headgaskets, granted the headgasket is a weak spot in those motors but they use them to lower the compression on a stock motor. HG, pistons? And change cam?

[uxojerry]

If your at 10:1 with a forged bottom end you could probably get what you want with a thicker head gasket, blower cam swap, and a blow thru carb. I am about convinced to do this on my next scratch build because it is so simple and effective. The blow thru uses the fuel for lowering iat's and most are not using an intercooler. This type of build is an art so you would need to find an experienced guy to help with the mods. 700hp maybe with race gas or E85, 600hp with 92. You would have a daily drive pulley and a smaller pulley for E85/race gas.

Super chevy modded a BBC 502 and got 1073hp with the whole build costing $13k from scratch. My guess is your 700hp could be done for less than $5k.



The general consensus is your block is the weakest link but will live long at 600hp. An occasional run of 700hp shouldnt hurt it. Consensus is the vortech units run cooler, which might be important with no intercooler.

Steve Morris Racing Engines - D1SC kit $3.5k, Blow Thru $1k-, cam swap, gasket change, head studs, $1k-. Add in a good tune and your at $5k.