Twin or single turbo charged

[lord james]

I've been reading the posts and viewing web sites from those who have walked the turbo road.

I'm current thinking of getting/building a engine about 350-400 BHP (forged pistons) and Slapping 1 or 2 turbo's on, and adding a anti lag kit for showing off.

What power output could I expect from one turbo and from two turbo’s.
What engine, block whould be best to use.
I want to end up with about 500-600 BHP.
The Twin Turbo Car in Sweden has the turbo mounted very close to the side pods.
But the one in America has them fitted close to the gearbox and rear shocks.

I am concerned about over heating
Cockpit Noise
Standing DB for track days.

[donkeasy]

Besides heat I am always worried about breaking.
Had a few selfmade ones, in the end they all broke.
Even the TIG welded chrom-molybdeen ones,
who were carefull unloaded in oil and sand.

Joop

[F.M]

You would be better going for a late model small block...5.7 LS1. Power will come down to comp ratio, boost and efficiant intercooling. You will be able to make 500-600 without running high boost, stressing pistons from the larger american V8`s than you would with a rover block. Intercooling has to be very well done due to heat build up with water injection or even nitrous as a secondary measure to bring down combustion temperatures. Best wishes.

Twin turbo is the way to go, no nasty crossover pipe...

>> Edited by F.M on Friday 13th January 19:24

[Boosted Ls1]

I've got a turbo lsx on the stand here. It's basically a stock block, crank and rods. I spent a bit of money on custom pistons, pins and a very nice ring pack. It's on a lowly 7:1 c/r but I can raise compression by using different lsx heads. So nothing to complicated. It should handle 15-20 psi boost and as said a lot of the parts are easily replaced. I've done cast exhaust manifolds for it configured to mate to a pair of GT28's.

Early lsx blocks are the strongest but if you're not revving any block should do.

As for the power output, a big single or a pair of twins can make similar power. In many ways it's down to cost and packaging. I don't like link pipes either.

Boosted.

>> Edited by Boosted Ls1 on Friday 13th January 19:43

[donkeasy]

If the question is 1 or 2,
I would go for 2 turbo's.

If you are concerned about heat.
Better is 2 small blowers,
A friend tuner sells them cheap.

Interested?

Joop

[Hugger Z]

donkeasy said:

Besides heat I am always worried about breaking. Had a few selfmade ones, in the end they all broke. Even the TIG welded chrom-molybdeen ones, who were carefull unloaded in oil and sand. Joop

A lot of guys on LS1tech.com/forced induction make brackets to support the Turbos rather than counting on the exhaust manifolds to support that weight. They tie the brackets back to the engine block or maybe transmission in this case of you are mounting them in that area. That would prevent manifold cracking. Material selection of the manifolds is also important. Stainless Steel has the least amount of heat transfer (thus more heat in exhaust to drive the turbo), but has the highest coefficient of expansion. So when making SS headers expansion slots are needed in the flange (mounts to engine block). Or sectioned flanges are necessary to allow the material to expand and contract without shearing header bolts or cracking header pipes.

There is a ton of information in the LS1tech forced induction forum. There are guys in there with LS1's, LT1's, and SBC's. You can also check out the Conversion forum, lots of turbo's LS1's and SBC's in there too. I strongly suggest you do a search or just read posts. You will find all the info you need and more.

www.ls1tech.com/forums/forumdisplay.php?f=9

[donkeasy]

If I understand it right,
You describe the basics of how a manifold should be made.
Are you a manufacturer?

When you have also manufactured exhaustpipes,
reading the text you do.
You also know that you have to throw a few away,
before it works

No hard feelings,
Almost all my cars have turbo and like it.
But having changed the factoryexhaust of my cosworthengine a few weeks ago.
I just had to share my worries.

Thanks for the tip of the side.

Joop

[andygtt]

I've gone for twin turbos on my V12 and I've speced them so they will provide boost (10-15psi) with ease.

I had a modded cossie for 10yrs, however I had an incident were the heat from the hydrib turbo actually boiled the brake fluid and thus total loss of brakes. I upped the size of the hybrid turbo for exactly the same power and mid range but as it didn't work as hard it didn't produce as much heat.


Heat will be the enemy in an Ultima turbo application.

[donkeasy]

Hi Andy

Nice workshop/new project.

I have mine not so long ago changed into a turbo-tecnics one with different bearing, hybrid etc,
Can had suddenly power from 3000 till 6750 rpm.. Super.

Sorry to hear the car is crashed.

Good luck with your projects, would like to see pictures of the V12 fitted

Joop

PS: of my engine with old turbo have to make new ones.

[URL=http://imageshack.us][/URL]



>> Edited by donkeasy on Saturday 14th January 11:51

>> Edited by donkeasy on Saturday 14th January 12:07

>> Edited by donkeasy on Saturday 14th January 12:08

>> Edited by donkeasy on Saturday 14th January 12:09

[andygtt]

The car was rolled in 2000.... I picked up a new shell 2 days later and re-built it to better than new standard, with huge 6pot Tarrox stoppers that are now going on my R1 powered indy!

[donkeasy]

I like them a lot, a thinking about using 6 pot on the Ultima.
Do you have that on your ultima also?

Are you not worried that the 6 pot system on the road in such a light car is "overbraked"
Not a good feeling in the pedal, as we say?

[andygtt]

The thing with extra pots is that they give extra feel, I don't think they give extra clamping unless they have a larger pad.... the std factory brakes that were on my Ultima (Ive sold it) were the old high spec kit and were completely wooden and I am sure this is down to the reduced number of pots compared to the newer high spec AP kit (pad size on the front was the same).

[Boosted Ls1]

andygtt said:

The thing with extra pots is that they give extra feel, I don't think they give extra clamping unless they have a larger pad....

Extra total piston area will give more clamp, force being proportional to area and all that. With no increase in pad area the brakes may feel sharper for a given amount of pedal travel? If you could increase pad area you'd feel sharper brakes.

Boosted.

[donkeasy]

Thanks for the reply's,
other info / suggestions are really welkom.