cheap custom turbo?

[ender2664]

Given that this is a daily driver, i would really not drop 6k to turbo charge
the car.
Can you tell me why the following idea/setup wouldn't work? Or maybe it can.
Given that i am only trying to make 7-10psi and there are hondas out there
pushing WAY more psi than that, shouldn't i be able to spool a smallish
turbo capable of making 7-10psi off one bank of cylinders?
If so, couldn't I just cut out a section of pipe going from the head to the
Y-pipe mount the turbo there and then run a tube from the turbo to the intake
manifold or run it through a front mount?
Seems like it would be a pretty cheap set up. Not the most efficient in the world, but for the cost pretty good.

[GretchenGotGrowl]

Sure, you can build a custom single turbo setup. PT_Killa did it a long time ago. There are two things to consider:

1) PSI is pretty irrelevant unless you are comparing two nearly identical turbos. You make power by adding more air and fuel to the engine. One turbo may pump 35 cubic feet per minute (CFM) at 10 psi and another may only pump 20. The one pumping 35 CFM will make more power, provided you can deliver the fuel. It is possible to put a really large turbo on our cars and pump enough air at 10 psi to make a lot of horsepower, but things will still break and it will probably have a lot of lag.
2) Cheap is never the way to go. Yes a single turbo is less than two, but don't buy a cheap turbo for that single one, and size it right.

[ender2664]

"One turbo may pump 35 cubic feet per minute (CFM) at 10 psi and another may only pump 20. The one pumping 35 CFM will make more power, provided you can deliver the fuel."
Doesn't the car have a good enough stock injection system to support a decent amount of boost?
"It is possible to put a really large turbo on our cars and pump enough air at 10 psi to make a lot of horsepower, but things will still break and it will probably have a lot of lag."
I see you are putting 647 to the ground...what of yours has broken? I thought the engine would be able to take a decent amount of power (450) without having issues.
2) "don't buy a cheap turbo for that single one, and size it right."
Any suggestions?

[GretchenGotGrowl]

Originally Posted by ender2664

"One turbo may pump 35 cubic feet per minute (CFM) at 10 psi and another may only pump 20. The one pumping 35 CFM will make more power, provided you can deliver the fuel."
Doesn't the car have a good enough stock injection system to support a decent amount of boost?

What I'm saying is it isn't the boost, it is the total amount of air. 10 psi of boost in one turbo may be a lot more air than another turbo. If you buy a single turbo that can pump 60 CFM at only 10 psi you will not have enough fuel with the stock system.

"It is possible to put a really large turbo on our cars and pump enough air at 10 psi to make a lot of horsepower, but things will still break and it will probably have a lot of lag."
I see you are putting 647 to the ground...what of yours has broken?

The first thing to go will be the ring lands, then the rods. Both should be good to around 550 HP at the crank, if you keep crankcase pressure in check.

I thought the engine would be able to take a decent amount of power (450) without having issues.

Yes, but you will start running out of fuel at that point. Manual transmission guys can get a little more out than the automatics, but the HPFP is really struggling. If you go with a small turbo that makes a lot of power down low (spools fast), then you will build a fuel deficit in the middle of the RPM range and the HPFP can't keep the fuel pressure up at the higher RPMs.

2) "don't buy a cheap turbo for that single one, and size it right."
Any suggestions?

Look for one that has ceramic ball bearings and water cooling. I like the Borg Warner EFIs, but they are too long to probably fit in the engine bay or behind the transmission. They would work great as a rear mount, but then oil scavenging will be an issue. Garret also makes some good turbos.
.
As for size, it really depends of what you want your power curve to look like. Look for ones that are rated for an engine between 3.0 and 5.0 liters. Then look at the compressor maps and see how much air the are flowing near the peak at various pressures. Since you are looking for around 450 RWHP at 10 psi, I'd look at the 0.8x A/Rs or larger with about a medium sized inducer wheel. That will keep it from spooling so fast that you get a fuel deficit but won't be super laggy.

Hope that helps.

[DSX_Camaro]

What about the LF3 HPFP?

[GretchenGotGrowl]

Originally Posted by DSX_Camaro

What about the LF3 HPFP?

That and a ZL1 in-tank pump will give you a lot of fuel. However, you have to do some fab work to make the LF3 pump work and pulling the tank to swap to a ZL1 pump is a PITA. Unless you want to go through all that, just be happy with what the stock pumps will deliver. 450 RWHP is nothing to sneeze at after all.

[Pt_killa]

Originally Posted by GretchenGotGrowl

Hope that helps.

If you don't want to dish out the cash for a ball bearing turbo, a cheaper journal bearing turbo in the rear will be just as reliable since the turbo doesn't get as hot back there but make sure to run a powerful oil pump to avoid the scavenging issue. A Turbowerx Exa pump is powerful enough to scavenge 2 turbos directly from the drain without needing a sump box.

The big annoyance with rear mounts is the placement of the intercooler piping. For the STS style build, the pipe runs along the passenger side of the car so it hangs low. However, I recently solved that issue a few months ago when I built my twin rear mount setup. I found a path to run the intercooler piping above the exhaust without too much hassle. (Look at the twin remote turbo album in my profile for pictures of the setup).

[OfficiallyTook]

Originally Posted by GretchenGotGrowl

That and a ZL1 in-tank pump will give you a lot of fuel. However, you have to do some fab work to make the LF3 pump work and pulling the tank to swap to a ZL1 pump is a PITA. Unless you want to go through all that, just be happy with what the stock pumps will deliver. 450 RWHP is nothing to sneeze at after all.

So buy a zl1 fuel tank & a lf3 hpfp for us LLT guys and were good to 10 psi+?

With twin turbos
Custom pistons rods ported heads hardened bolts lf3 ported intake manifold zl1 fuel tank lf3 hpfp and were good?

[GretchenGotGrowl]

Originally Posted by OfficiallyTook

So buy a zl1 fuel tank & a lf3 hpfp for us LLT guys and were good to 10 psi+?

With twin turbos
Custom pistons rods ported heads hardened bolts lf3 ported intake manifold zl1 fuel tank life hpfp and were good?

Again, depends on the setup. Turbo A @ 10 psi <> Turbo B @ 10 psi.

[OfficiallyTook]

Originally Posted by GretchenGotGrowl

Again, depends on the setup. Turbo A @ 10 psi <> Turbo B @ 10 psi.

Of course I would go with some dual ball bearings... Gt28rs'

I just want to make sure my part list is as accurate as can be before I start...

And with you and the rest of camaro5 I will get their one day =)

Oh, and come ooon HPtuners (LLT)

Wot

[SSE 4 2SS]

Originally Posted by ender2664

Given that this is a daily driver, i would really not drop 6k to turbo charge
the car.
Can you tell me why the following idea/setup wouldn't work? Or maybe it can.
Given that i am only trying to make 7-10psi and there are hondas out there
pushing WAY more psi than that, shouldn't i be able to spool a smallish
turbo capable of making 7-10psi off one bank of cylinders?
If so, couldn't I just cut out a section of pipe going from the head to the
Y-pipe mount the turbo there and then run a tube from the turbo to the intake
manifold or run it through a front mount?
Seems like it would be a pretty cheap set up. Not the most efficient in the world, but for the cost pretty good.

If I follow what you are asking correctly, no, running a single turbo off of one bank isn't possible... There would be a gross imbalance in back pressures and this would be a tuning nightmare... Remember, for every pound of boost, there is a pound of back pressure... You would create say ten lbs of back pressure on the one bank and none relatively speaking on the other bank... I may be completely off base here but I've never even heard of this being tried... Gretchen can offer more, and maybe I'm reading this wrong...

Your best bet would be to pipe both banks to a single turbo, or twins though that defeats your purpose of less expensive... though the piping can get pretty complex... It's been done and can be again...

I can honestly state there is no benefit to going cheap, either in the design or the components of a turbo system... It will end up costing way more in the long run... Please trust me on that one... Poorly designed systems that are within a budget can lead to a yard trophy that can't be fixed financially...

[JantzenOKC]

Originally Posted by SSE 4 2SS

I can honestly state there is no benefit to going cheap, either in the design or the components of a turbo system... It will end up costing way more in the long run... Please trust me on that one... Poorly designed systems that are within a budget can lead to a yard trophy that can't be fixed financially...

And even when you do it the right way, you might still have to throw more money at it! I'm up to about $8,500 just in parts in the last couple months on my turbo build.

[GretchenGotGrowl]

Originally Posted by OfficiallyTook

Of course I would go with some dual ball bearings... Gt28rs'

I just want to make sure my part list is as accurate as can be before I start...

And with you and the rest of camaro5 I will get their one day =)

Oh, and come ooon HPtuners (LLT)

Wot

I'll have to look at the compressor map and flow data for that one, but if I hazard a guess I would say 10 psi on a single one would not require more fuel than either pump can deliver. However, tuning is still the issue so "can deliver" and "will deliver" may be two different things.

As for the internals, I think you have to decide that one for yourself. Can't_C_Me is pushing about 500 RWHP on stock internals and I think he broke a ringland on one piston. He replaced it with a stock one and didn't have another one break. If you want to be safe, forge the pistons and rods.

[GretchenGotGrowl]

Originally Posted by SSE 4 2SS

If I follow what you are asking correctly, no, running a single turbo off of one bank isn't possible... There would be a gross imbalance in back pressures and this would be a tuning nightmare... Remember, for every pound of boost, there is a pound of back pressure... You would create say ten lbs of back pressure on the one bank and none relatively speaking on the other bank... I may be completely off base here but I've never even heard of this being tried... Gretchen can offer more, and maybe I'm reading this wrong...

Your best bet would be to pipe both banks to a single turbo, or twins though that defeats your purpose of less expensive... though the piping can get pretty complex... It's been done and can be again...

I can honestly state there is no benefit to going cheap, either in the design or the components of a turbo system... It will end up costing way more in the long run... Please trust me on that one... Poorly designed systems that are within a budget can lead to a yard trophy that can't be fixed financially...

100% agree on needing the back pressure to be fairly even. I'm not sure if the 1:1 rule still applies, but even it is slightly less back pressure to boost ratio with the newer ones, it is insignificant.