ls1formula99

Just curious on opinions on what is a better over all steup and why, a twin turbo or a single? Ryan

bo0oost

Since our motor is a V motor, I'd say twin. More efficient, and less piping (from one header to the next, to mate to one turbo, on a single system).

White_Hawk

iTrader: (3)

Number one on the boosted list is still a single turbo (for now at least). All things equal, I would get the single. Theoretically, it should be cheaper, with only one turbo - the turbo itself is a big cost driver, and only one exhaust manifold to fabricate. I got a hunch that Rob's kit will be the best value (HP for the money), especially when he releases the tuner kits.

-Geoff

<small>[ February 10, 2003, 01:53 PM: Message edited by: White_Hawk ]</small>

bgreen

I've worked with both, would rather have a single now.

Reasons: purely reliability & maintenance, twice as much to go wrong, usually more plumbing.

2 turbos to break
2 wastegates to maintain & set
2 oil feeds
2 oil returns
2 exhaust downpipes
2 turbo to intercooler setups to plumb

Also, FWIW, I was told by PTE that a single turbo will be more efficient than a twin - simplest reasoning - add another widget to a system, it is just another piece that will be absorbing (wasting) energy.

In the Fbody/C5 world, physically fitting a single turbo comes into play, and a twin setup may work well, due to the fitment constraint. I haven't seen the plumbing for Rob's car, but I'd like to see the design.

zturbo

For what most want a single turbo hits alot of these goals.
I have both as well, twins imo do not fit as easy in the fbodies. Especially if you want to retain assecories.
I feel a single can be setup great, have not seen a single turbo system produced, I am not fond of log manifolds at all (from a manufacturer) that I like as of yet. Everyone has there own oppinions. I would like to see a single turbo system with the turbo mounted higher than I have seen so the oil drain back is easy on all the internal parts. The intercooler piping and so forth is made easier as well with this too.

Twin turbos, pretty much the only place for the turbos is right beside the block, like incon, and all the other systems.

If i was to do a ls1 car for myself it would be a single T70-T74, using a q or r trim wheel. Have a set of headers with a y pipe going to where you have the turbo mounted. Run a larger single air-water intercooler with a heat exchanger system. (do it like the vortech system but on a bigger scale.) Headers would be made out of .062 wall 321 stainless steel. Wastegate would be one larger single wastegate (possibly a progate from innovative) Mount the wastegate right before the turbo in the y pipe. Downpipe would be 4" transitioning into 4" oval tubing to get under the K member, or over the control arm.

Every system has its bennefits and comprimises you just have to figure out what you are willing to comprimise on.

For my racecar I love the twins, i think they fit in very well for the car, but for a street car would just be alot simpler to have a big single.

Pro Stock John

iTrader: (34)

Based on my research up to like a T76 single works well, stuff above that is noticeably more laggy.

Twins don't have as many spool up issues but you have twice as many turbo parts to keep an eye on,

MIGHTYMOUSE

iTrader: (59)

twins are great for a small cid car because they are moving lots less air, and 2 litte turbos are easier to spool.. but on a v8 such as ours spool difference is negligable imo.. twin turbo sure does have a nice ring to it, but the singles make that 18wheeler jet engine sound that you never get tired of!

VINCE

iTrader: (1)

I would think a Single would do just fine..

verbs

It does seem that you get a buttload more torque from the single turbos though. And the difference in lag isn't that big since our engines flow a decent amount of air/exhaust to begin with.

purevilss

Oh, what I'd do to get the wife to allow me a nice big single mounted under my hood!!! <img border="0" alt="[evil]" title="" src="graemlins/gr_devil.gif" />

chasgiv3

iTrader: (1)

Just for comparison I found a single Turbo that can match the flow of my Twins. My twins have 60 series wheels in them.

Here's a picture of it. Do you think you'd have lag with this one?

<img src="http://www.mjmturbos.com/images/BIGT90.jpg" alt=" - " />

zturbo

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">The other thing that makes me think is the guys who drag race that switched from singles to twins and some even running quad?

Why are they doing that? Is it the rules? Or could it be some sort of performance reason? </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Cause the rules allow. Most of the rules were centered around single turbos for most classes as the twins would make insane power and spool faster. So they were limited to a single turbo. Now The quad turbo that moran ran I have heard is now gone in favor of a twin setup.

chasgiv3

iTrader: (1)

I personally don't like the long crossover pipe design of the singles out there.

I have seen a few that have balanced piping feeding the turbo. Those I like! One short run on one side versus a very long crossover pipe scares me from a tuning standpoint. I would imagine one bank to have different fuel requirements than the other in that case. The only other issue I see with a single is the downpipe. I have dual 3" downpipes in my design. A single would require what? 4" downpipe? Bigger? Not sure what the equation is.

But I do like the simplicity of a single turbo design. Less wastegates, oil feeds, oil returns, tubing, IC piping etc.

Having two pretty large turbos instead of one REALLY huge turbo makes sense. But having dual everything can get a bit expensive. Unless you get a really good deal.

Honestly if both systems are designed properly I don't see much a performance difference between the two. Even in spool up it'll be close. But the twins would definitely have the advantage in a road race situation.

The other thing that makes me think is the guys who drag race that switched from singles to twins and some even running quad?

Why are they doing that? Is it the rules? Or could it be some sort of performance reason?

JimmyKash

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by chasgiv3:
<strong> Just for comparison I found a single Turbo that can match the flow of my Twins. My twins have 60 series wheels in them.

Here's a picture of it. Do you think you'd have lag with this one?

<img src="http://www.mjmturbos.com/images/BIGT90.jpg" alt=" - " /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">LOL....that 90mm is a bit excessive. A pair of 60's is good to 1200-1300hp if you really push them hard. A PTE-88 will give you the same kinda horsepower and is pretty streetable. Even one of those really expensive 76s in a large frame thumper housing can do it too....look at the drag radial class

chasgiv3

iTrader: (1)

Dave, I'm surprised by your statement.

We've got 700+RWHP already on LS1 type motors last year. Now this year the goal HAS to be at least 800RWHP. No? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Waste of effort???????? OMG! You must be joking.

A 1000RWHP is NOT a waste of effort either. It's just a goal that's WAY out there. Are you saying LS1's shouldn't even try? I'm sorry but I don't share your attitude.

Now if your saying the common LS1 owner probably wouldn't want to spend the cash to support 800RWHP then I can agree with that. 700RWHP is plenty so is 600 so is 500 hell so is 400. You have to decide when to quit. How much time, cash and effort you want to put in.

Now back to the thread....

What HP levels do you want in your Turbo car? You've got to ask yourself what your goals are. Based on that then you can make a better decision. You need to see what size turbos you'd need to get you to your HP levels. Then check which of the available kits can fit a Turbo to meet that goal. Also consider where you'd like to be in 2 years also.

2000LS1

Single vs. Twin:
Reliability/Maintenance - SINGLE, less parts.
Value - SINGLE, less parts.
Torque - SINGLE (Rob's kit).
Lag Elimination - TWIN, spool faster.
Exhaust Advantage - TWIN, more equal lengths.
Exhaust Advantage On Big Cube Turbo Motor - TWIN (maybe?) is a single 4" downpipe enough for the flow of a 400+ci boosted motor? Wouldn't you benefit from dual 3"(or larger) exhaust + x-pipe over a single 4" exhaust? Also better ground clearance for those non-oval tubed exhaust cars running 4" downpipes.
A4 - SINGLE (maybe?) can make up for lag with converter aided launch.
M6 - TWIN (maybe?) turbos can make up for lack of launch (compared to converter-auto launch).
Streetability - ???
Power Potential - ???

Open to constructive critisim... these are just my theories based on what I've researched.

White_Hawk

iTrader: (3)

^^^^^ That is a great list.

-Geoff

<small>[ February 12, 2003, 03:27 PM: Message edited by: White_Hawk ]</small>

Pro Stock John

iTrader: (34)

Twins: excellent off idle and mid-throttle response.
Single: larger singles might require significant relocating of engine compartment items

VINCE

iTrader: (1)

I say there is enough of us to drop in $1k and build a 1000 plus rwhp LS1.. What do you think guys.. LS1TECH.com Car.. Take it to the Ford Shootouts and tax that Azz.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

y2khawk

iTrader: (5)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 2000LS1:
<strong> Single vs. Twin:
....
Torque - SINGLE (Rob's kit).
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ummm

twins can make torque just fine <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

heat and velocity is the turbo's friend, at least on the hot side of things. With a V-engine application it makes sense to go dual turbo. The turbos can be close to the exhaust ports.

I personally don't like cross-over tubes for the single applications. That's the main reason I went twin in the first place. I simply prefer less hot side plumbing over the addition of another set of everything, inlet/outlet tubes, IC, wastegate, etc.

Yes big singles can "support" over 1k HP.
Support and good for are two of the most improperly used phrases to me. Ever take a good look at the compressor maps for some of the thumpers?? Yeah, they reach choke flow at over 100 lb/min of air and have a broad center island efficiency. But have you ever stopped to consider how much pressure it will take to get to that point on even a 400 cu in motor?

but say you got this 1400 HP turbo, but you're boosting to say 12 psi. Where do you end up on the compressor map?? i'm gonna guess on some of them you'll be way off on the efficiencies. So, you end up with a hotter charge, a slower spool, and a big turbo <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Sometimes a pair of "smaller" turbos put you into a better operating range than a big single. It all depends on the motor, power level, boost pressure, IC strategy.

So what if there are more parts?? I hate to say it, but a serious turbo setup and cheap DO NOT go together <img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" />

after all, your motor is simply an air pump. How much you push on it, either from a big single or a couple small turbos, ultimately determines the total flow.

But be on the lookout, i think the twin cars may be something to watch out for this year <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" alt="[evil]" title="" src="graemlins/gr_devil.gif" />