Twin Turbo or No Twin Turbo

**artistwantab** · 11-21-2011, 02:48 PM

I need some advice on a future build.

I am trying to pick a LS1 that I will modify with a goal of 600-800 horses and everything I read discourages twin turbo's on aluminum LS1's.

If you guys had a stock LS1 and wanted 600-800 horses what direction would you guys go.

Also any year better than other for a donor car for the LS1+

Thanks in advance for the help.

**artistwantab** · 11-21-2011, 07:45 PM

I posted this in the wrong section....

Was intended for the LS? general help section.

Sorry tried to delete it but don't have admin rights.

**98maro** · 11-21-2011, 08:25 PM

Don't know alot bout turbos. But I'll go for twin turbo if you can.
600-800 goal is kinda high for An ls1 motor. I can probably hold up to those numbers. But IMO I would for a LQ4/ LQ9 iron 6.0 block. For what I know it's stronger than ls1 and works great with forced induction.
And of course more cubic inches!

Welcome to ls1.com.

**35th-ANV-SS** · 11-21-2011, 08:30 PM

I'm pushing 500rwhp on 8psi and I'm guessing my motor is not even sneezing at that kind of power.

With any FI build, the most important thing is keeping IAT's down (intercooler and methanol injection) and having the tune spot on. There are plenty of people pushing that envelope on both superchargers and turbo's with the LS1 motor.

Cubic inches isn't really all that important when it comes to FI.

Small blocks love it and you naturally want a lower compression if you run more boost. Ideally with that kind of power I'd guess you'd want to be about 9.5:1 or so. I could be wrong though.

Obviously, before you could ever put that much power down, you'd need a fully built car from the ground up...rear end, suspension, drive train, tranny, tires, etc.

**artistwantab** · 11-22-2011, 09:45 AM

Thank you for the replies.

The car will be fully built from the ground up.

I am trying to decide between twin turbos or other modification to get that 600-800hp goal. I hear a lot of issues with twin turbos or any sleeved aluminum block with twin turbos. I think 8-10 boost is about as high as people recommend or you can have issues.

@98maro

The LQ9 may be exactly what I am looking for. Need to make sure it fits and twin turbo will be where I am headed.

**35th-ANV-SS** · 11-22-2011, 06:03 PM

Are you talking about rear wheel power or flywheel? I'd be more concerned about a specific ET and not so much on a power goal.

I've seen plenty of LS1's pushing 14+ psi on a forged bottom end which would easily hit your target either way.

Obviously if the aluminum block has you worried, like mentioned, you'd be best off with swapping in a 6.0 iron block and then you can run a ton of boost.

IMO, turbo cars are more track driven where-as supercharged cars are more for the street which is why I chose a Procharger.

For what it's worth, a member here is running a single Turbonetics 76mm trim with around 8-9psi and hit over 600rwhp.

**artistwantab** · 11-23-2011, 08:15 PM

I am looking at the RWHP....600 RWHP being a start.

Just wondering the best ways to get that from am LS1. I am thinking to go away from the Twin Turbo and maybe other mods to get that goal.

**35th-ANV-SS** · 11-25-2011, 09:13 AM

You will not hit that goal without FI. Turbo or Supercharger is the only way staying with the LS1 motor.

**artistwantab** · 11-25-2011, 10:28 AM

Thank you.

It looks like my choice will be the LS6....Very similar to the LS1 but an iron block and other mods.

That way I can upgrade it to a twin turbo if I can't get the HP that I want and I don't have to worry about keeping the boost low.

You have helped me a ton.

**artistwantab** · 11-25-2011, 02:32 PM

If I didn't make it clear basically the LQ9/LS6 that was recommended to me above.

Just makes the most sense.

**35th-ANV-SS** · 11-26-2011, 06:14 AM

The LS6 is an aluminum block. LS6 and LQ9 are TOTALLY different.

The LS6 shares its basic block architecture with the LS1 engine, but other changes were made to the design such as windows cast into the block between cylinders, improved main web strength and bay to bay breathing, an intake manifold and MAF-sensor with higher flow, a camshaft with higher lift and more duration, and sodium filled valves.

An LQ9 is a 6.0L iron block.

**artistwantab** · 11-26-2011, 09:07 AM

Sorry wikipedia confused me. Refers to it as a truck version of LS1 in the LS6 section.

I drew the conclusion that it was an LS6 that was reworked and referred to as a LQ9 but really an LS6 with some changed.

walks like a duck, talks like a duck.....must be a duck.

4.00 in bore blocks (1999–2007)

The 6.0 L is a larger truck version of the LS1, with the exception that the blocks were cast of iron, and was designed to bridge the gap between the new small blocks and big blocks in truck applications. There were two version of this engine: the LQ4 and the LQ9, the latter being more performance oriented. Although the block of the 6.0L looks similar to the LS1, they are iron instead of aluminium.

**35th-ANV-SS** · 11-26-2011, 09:59 AM

Iron blocks are of course stronger and if you plan on boosting it a lot, iron block is the way to go. The LS1 block is lighter and strong too though. 600rwhp is not out of the realm of a LS1. I hit 540rwhp on 9-10psi.

**extremecorvette** · 01-10-2012, 06:42 AM

Are you going to leave the motor stock or build it? If your going to leave it stock I love the LS6 and I would think you could make 550-600 rwhp on it safely. To hit 700-800 rwhp your going to need to build the motor and at that point it, might be worth looking doing a LS7 or LSX motor. I did a Worlds Castings WarHawk LS7 block with LS7-X 6 bold heads and made 880rwhp and 900rwtq on pump gas but again it cost about $45k to put that system together. Granted I went a little over board with buying higher quality parts since I want the motor to be bulitproof, or close as posable to it.

**Nowhereman** · 01-10-2012, 06:03 PM

Originally Posted by artistwantab

I need some advice on a future build.

I am trying to pick a LS1 that I will modify with a goal of 600-800 horses and everything I read discourages twin turbo's on aluminum LS1's.

If you guys had a stock LS1 and wanted 600-800 horses what direction would you guys go.

Also any year better than other for a donor car for the LS1+

Thanks in advance for the help.

If something is good, I always do it twice.
Having said that, your HP figures for a stock block are a little out of reach unless you want to trash the motor in a short time.
Twins will give you better response for sure.
Just dial that waste gate down so you don't thow metal objects out into the street...

**NaviDyn** · 01-11-2012, 04:51 AM

Originally Posted by 35th-ANV-SS

I'm pushing 500rwhp on 8psi

Cubic inches isn't really all that important when it comes to FI.

So then a Civic with a 1.6 and the vetc has kicked in will hit 500 at 8 psi?

**extremecorvette** · 01-11-2012, 05:38 AM

LOL Cubic inches is very important when it comes to FI for sizing the turbos, FMIC, and the system. I've never seen a Civic with a 1.6 make 500whp but I have seen a S2000 with a 2.0 make 450-500whp with trubo and meth. Granted that car made that power at around 6,500rpms. I found a kit for my BMW 07 335xi that already has twin trubo from the factory and with the kit the car can make 420awhp and 476awtq for $2k in parts. The turbos on that car kick in so that pick tq is at 2,200rpms, and pick hp at 5,500rpm. That system also is running meth.

I agree 500-600 rwhp on a stock motor is pushing the motor

**35th-ANV-SS** · 01-11-2012, 07:27 AM

Originally Posted by NaviDyn

So then a Civic with a 1.6 and the vetc has kicked in will hit 500 at 8 psi?

My point was that smaller engines such as the 346ci engine handle low level of boost well, even stock. He said he wants to use his LS1. Obviously if you have a 427ci motor vs a 346ci motor the 427ci will make more power keeping all things equal.

**extremecorvette** · 01-11-2012, 08:34 AM

I've seen a good number of people run a stock LS motor with low boost 6-7 psi, I don't know enought to say that 8-9 psi would work because of the CR and setup. But I know guys running stock LS7 motors with the ASP kit getting 620-640rwph on 6 psi, that also a 427ci motor stock making around 420rwhp. There use to a company out of Quad Cities that use to make a very nice turbo kit for the C5, and F-Body cars that ran 6-7 psi on a stock LS1 and got around 500-550rwhp.

**35th-ANV-SS** · 01-11-2012, 08:41 AM

Originally Posted by extremecorvette

I've seen a good number of people run a stock LS motor with low boost 6-7 psi, I don't know enought to say that 8-9 psi would work because of the CR and setup. But I know guys running stock LS7 motors with the ASP kit getting 620-640rwph on 6 psi, that also a 427ci motor stock making around 420rwhp. There use to a company out of Quad Cities that use to make a very nice turbo kit for the C5, and F-Body cars that ran 6-7 psi on a stock LS1 and got around 500-550rwhp.

I have a stock LS1 making 500rwhp on 8psi. Have about 5K miles on this set-up. Also running a meth kit and FMIC. Tuned by FROST on this site and he said it was tuned conservative. Surprisingly the car was pulling upwards of 10psi above 6500RPM on the stock cam. This is when we set the rev limiter back and limited the boost to 8psi being I have a stock bottom end. Only thing I changed were valve springs and added hardened push rods.