Calling for LS advice and recommendations

[DangerousDerek]

So now is finally the time to turn to the dark side.

I intend to twin turbo an LS. I had in mind a LQ4 6.0 but have been offered a 4.8 which is from a 2003 Silverado and hasn’t an iron block and ally heads.

Any reason I should steer clear or shall I pull the trigger and start making this happen?

[fullpull]

You know you have to do it. It’s gonna be a trip!

[anonymous-user]

The more common the conversion, the more useful and available the advice. Go with the engine most commonly used to upgrade similar cars Derek

[DangerousDerek]

TVRMs said:

The more common the conversion, the more useful and available the advice. Go with the engine most commonly used to upgrade similar cars Derek

I aint trying to build something common though.

[RichardD]

DangerousDerek said:

I aint trying to build something common though.

That is a LR4 engine then?

From Wikipedia standard output from the 4.8 is 285bhp (a very RV8 number), so I assume you will be looking for lots of boost (16psi up)?

http://www.superchevy.com/how-to/engines-drivetrai...

shows that 100bhp/litre is do-able with the short stroke by changing heads, cam and intake .

Budget Boost! http://www.gm-efi.com/tech/budget-boost-low-buck-t...

Edited by RichardD on Friday 13th October 09:18

[DangerousDerek]

RichardD said:

That is a LR4 engine then?

From Wikipedia standard output from the 4.8 is 285bhp (a very RV8 number), so I assume you will be looking for lots of boost (16psi up)?

http://www.superchevy.com/how-to/engines-drivetrai...

shows that 100bhp/litre is do-able with the short stroke by changing heads, cam and intake .

Budget Boost! http://www.gm-efi.com/tech/budget-boost-low-buck-t...

Edited by RichardD on Friday 13th October 09:18

Thanks for that Richard, certainly looks like a strong motor as standard to take some boost.
I hated seeing that these baby 4.8s can be found for $250 in the states. Ive been offered one fully dressed and delivered to my door for £2750 and I am seriously considering it.

[RichardD]

DangerousDerek said:

... seriously considering it.

I didn't realise until a few minutes ago, it is an iron block.

http://www.turnkeyenginesupply.com/lr4-4-8-remanuf... Not sure if you know/mind(?)

Out of interest what transmission would you plan to link up to a LS? (To perform well on the strip...obviously )

[DangerousDerek]

RichardD said:

I didn't realise until a few minutes ago, it is an iron block.

http://www.turnkeyenginesupply.com/lr4-4-8-remanuf... Not sure if you know/mind(?)

Out of interest what transmission would you plan to link up to a LS? (To perform well on the strip...obviously )

I would like a 6 speed but al the drag racing lads tell me to go auto!
A 4l80 might be too big to fit but a glide is much smaller and bullet proof.
Not sure I want an auto for what will still be a used car on the road and track

[Boosted LS1]

A TH400 will give you the strength you need at very reasonable cost. :-) It's what I've chosen.

[RichardD]

DangerousDerek said:

I would like a 6 speed but al the drag racing lads tell me to go auto!
A 4l80 might be too big to fit but a glide is much smaller and bullet proof.
Not sure I want an auto for what will still be a used car on the road and track

800nm = 590lb/ft, so a 4l80 would also be potentially not up to spec for a blown LS too, depending on how much boost you ran. But probably not by too much. (I know the last two digits of the GM boxes are nm torque rating due to having a boring car with an under specced GM gearbox relative to just a dinky diesel engine!).

But there would be hardly any change-lag delay between gears so I get why they are recommended.

(Thinking though, I think a box decision should be taken when you have a clear idea of the characteristics of a new engine.)

[jesfirth]

Do you really want a heavy iron block in the front of a tvr? That will make a right mess of the front rear balance

[DangerousDerek]

jesfirth said:

Do you really want a heavy iron block in the front of a tvr? That will make a right mess of the front rear balance

I will simply place 80lb in the boot. That will even it up.
I am sure with 700 bhp+ it will hardly notice.

The engine is bought, he talked me into it with talk of short stroke, lond piston dwell, huge bhp numbers etc. I couldn't resist especially after bargaining the price down.

Finally Its actually going to happen at last. I can use these at last...

[jesfirth]

i will be interested to see the results

[Boosted LS1]

You'll only notice the weight on fast corners when the car wants to drive straight ahead :-)

[GreenV8S]

Locaterfield types seem to handle quite nicely despite a nose heavy weight distribution. I think the main drawback would be a lack of traction, and if this goes as well as I hope I think that's going to be a problem regardless of the weight distribution.

[DangerousDerek]

GreenV8S said:

Locaterfield types seem to handle quite nicely despite a nose heavy weight distribution. I think the main drawback would be a lack of traction, and if this goes as well as I hope I think that's going to be a problem regardless of the weight distribution.

I use Mickey Thompson drag radials. There wont be any traction problems on the strip but granted its going to be a handful if I go anywhere near the boost of the road tyres.

[300bhp/ton]

DangerousDerek said:

RichardD said:

I didn't realise until a few minutes ago, it is an iron block.

http://www.turnkeyenginesupply.com/lr4-4-8-remanuf... Not sure if you know/mind(?)

Out of interest what transmission would you plan to link up to a LS? (To perform well on the strip...obviously )

I would like a 6 speed but al the drag racing lads tell me to go auto!
A 4l80 might be too big to fit but a glide is much smaller and bullet proof.
Not sure I want an auto for what will still be a used car on the road and track

Not sure how much you want to use it on the road vs other uses. But for me a manual is way more fun.

I’ve got two LS1 Camaro’s at the moment. Almost identical. Nowhere near the HP you are talking I admit. One is a T56 6 speed. The other a 4 speed 4L60e auto. The latter is good. But the 6 speeder is just so much more entertaining all of the time on UK roads.

[RichardD]

DangerousDerek said:

...The engine is bought, he talked me into it with talk of short stroke, lond piston dwell, huge bhp numbers etc. I couldn't resist especially after bargaining the price down....

Congratulations, you have a base for lots of possibilities! What make/models are the turbos out of interest ?

Thinking back to the 1/4, with a manual box you will wanting to be maxing out in 3rd or 4th at the end... (3rd may be tricky due to rpm required.)

[RichardD]

More inspiration.

http://www.hotrod.com/articles/hrdp-1109-stock-gm-...

Four figure bhp is possible

[anonymous-user]

DangerousDerek said:

TVRMs said:

The more common the conversion, the more useful and available the advice. Go with the engine most commonly used to upgrade similar cars Derek

I aint trying to build something common though.

Didn’t intend to suggest that....

But now I see where you’re going