1987 Oldsmobile Cutlass Supreme

[beags86]

This thread is be my official build thread. I don't really want the poll and some of the miscellaneous discussion from the other thread.

Anyone new to the party can read some past history here:

https://ck5.com/forums/threads/87-olds-cutlass-supreme-you-vote-i-build.327651/

Anyway here's some current shots of the car.


As talked about in the other thread above the plan is a g-machine/auto cross car. With a eBay twin turbo set up.
Somewhere around 600hp with a good suspension. Nice wheels and paint and some subtle body mods.

 

[beags86]

Yesterday I picked up a 2005 6.0 LQ4/4L80E from a van

Full engine and transmission, full harness and engine accessories, computer.


It has around 140k on the ticker.

 

[cyclic]

Make sure you relocate the coil packs and add some classic "Oldsmobile" script to the valve covers.

 

[Babaganoosh]

I'm not to sure about boost but I have seen a specific g body swap kit.

I believe that is going to be a lq9 which is going to be flat top pistons and higher compression. Actually after reading it's a LQ4, which is more then plenty I love mine and of course the tune 208 did in it.

 

[Team208Motorsports]

Thats an LQ4. Biggest thing I would need to know before answering a TT engine... How much power do you want or are expecting? I ask because these make power in a hurry with forced induction. I have stock single turbo 5.3s out there laying down 10-10.5 sec runs. The power question with dictate the problems coming.

What do I need to know?
Depending on boost and build I really doubt you will be running the MAF. This is due to the air flow limit the ECM has. This is fine though, you would be running speed density with a boost build anyway. You can use the MAF but it requires scaling. Do you have emissions testing to worry about? I ask this for the reason that running speed density requires setting a MAF code to fault out the processing. Fuel system will need to be altered a lot. Flow through rails, reg, pump..... The stock ECM is totally capable of 3 bar boost operation with a custom operating system and a different map sensor.

What are the down falls of this engine?
Weak rods, RPM, injectors, cam.... All depends on power

What should I replace out of the gate?
Again, what power and boost?

What are the pros?
Its an LS and 4l80.

Who makes motor mounts outside of dirty dingo.
I do not know this one as we usually make our own.

Where's the best place for swap parts?
Try and use off the shelf store parts to save cost and better availability.

Anything to need to know about can bus gauges?
They work well to a point but things like oil pressure can be tricky sometimes depending on ECM, base tune and gauges. Pulling Speed, rpm, and temps is very easy. Nice thing too is with the 4l80 and a PRNDL switch you get selected gear though data line.

Where can I get a slip shaft for the back of the 4L80E? Or should I go back to the yard?
Most driveshaft shops can get them easy but would be cheaper from the yard.

There is a ton more to add but that will answer a few.

 

[beags86]

I shouldn't need much boost to reach my power goals. Power goal is 600 to start. Want to get the car running and driving and and start building the rest of the car before I start turning up the boost. I want to leave the motor alone out of the gate if possible, but I am not apposed to cracking it open for a cam if necessary. I'll probably dump the intake manifold for a car manifold, as I can't stand the truck intakes. I don't care how good or bad they are, this simply a personal taste thing.

 

[Team208Motorsports]

With that said you could do this in stages. If 600 is the goal up front. I'd just grab a car intake, correct injectors with rising reg, LS6 cam, better springs, rods, retainers, locks and seals. Limit to 6-8 PSI and be done.

Dont fall for the need of HUGE injectors, they need to be sized correctly to maintain clean idle. A boost referenced regulator can do this. 600 hp on boost only needs about 56 lb injectors at 80% duty cycle. Depending on what the reference rise is would point to what injector. If you want room to grow, a 60 lb deka would be a good start. With that you could run a static pressure and still have a nice clean idle. With a rising reg those are good to 800-1000 hp. If later on you want more boost you need better sealing so the heads are coming off. At that time I would put a real cam, lifter and head gasket in it. Hell, I'd look at destroking too........ The LS6 cam would be easy to sell as guys want them all the time. They are usually pretty cheap to pick up and a great budget start.

Any thought to air charge cooling yet?

 

[beags86]

Great info. Few things in there I knew, few I didn't,
Thanks.

I probably just go with a intercooler up front, but there is a big part that wants to go with a air/water box. I have a N2O kit I am currently not using and would have no problem spraying the intercooler to cool it down before a autocross run.
I also have no problems with a meth kit, and currently it's within my plan to use some water injection.

 

[folkenheath]

Yesterday I picked up a 2005 6.0 LQ4/4L80E from a crashed van.

Full engine and transmission, full harness and engine accessories, computer.

It has around 140k on the ticker.
Should be a decent starting point. Picked it up for $1300.

This will be a slow, slow build and I have many other irons in the fire. But if I purchase something for this or have any ideas I'll post them. Also technical questions as my build plan comes together.

So who's our LS guru's here.
@Chevy305, @Team208Motorsports, @Babaganoosh, @folkenheath, @sreidmx, @rjfguitar, @Stomis , oh hell I'm probably forgetting a few people but this will get me started.

What do I need to know?
What are the down falls of this engine?
What should I replace out of the gate?
What are the pros?
Who makes motor mounts outside of dirty dingo.
Where's the best place for swap parts?
Anything to need to know about can bus gauges?
Where can I get a slip shaft for the back of the 4L80E? Or should I go back to the yard?

Any general knowledge is appreciated!
Thanks!

That does look like a good starting point, sweet.

I am definitely not an LS guru, but I have built some and do have a few books if you need me to look something up. You know me, I can't swap a stock engine, I always have to change the cam at a minimum, which usually snowballs.

If you are only going for 600 hp with turbos I would barely touch it to start out with. Yeah you could change the rods and pistons for peace of mind, or you could be one of the many doing it on a stock bottom end. I met a guy on dragweek 2015 that was running mid 8s in an S10 with a stock 5.3 shortblock with turbos. Maybe change the cam but you can probably make 600 hp with the factory cam even with the right turbo headers and tuning. You definitely need bigger injectors. Go buy yourself a gas tank for a GN for cheap and drop that puppy in with a high flow walbro pump so you have the right fuel system in the car. Now if you plan to crank it up to more hp then you will need a bigger pump so plan ahead.

Factory downfalls, can be the stock rocker arm bearings, they are loose and can come out if damaged, at least press in the comp trunnion kit if you don't replace them with aftermarket (expensive).

Holley/Hooker make a lot of swap parts for LS engines, headers, motor mounts, etc. Although for turbos obviously you will need different headers. Stainless works makes some nice turbo headers that aren't too bad of price for being stainless.

I have never used the factory ECU or gauges so I have nothing there. I always go aftermarket.

The 4L80E is the same spline as a TH400(along with about half the internal components), although some have the o-ring on the shaft instead of a plugged yoke. If you run a plugged yoke just leave the o-ring off. If you run both you will feel the yoke trap air and want to force itself out like a piston when you install it. I am guessing you have a few truck TH400 driveshafts laying around somewhere.

 

[beags86]

Most likely I'll swap the cam and intake manifold. Do some valve train upgrades, and of course injectors.

I had told the guy what I was going to do and he just gave me everything and I mean everything, well I guess not the slip shaft yoke, ha. Even the motor mounts from the van, (you can see them on the engine) so I might see if and how i can make them work. Not sure yet.

My power goals are really quite low because I need to build alot of the rest of the car to even use 600hp.

Good tip about a GN tank, I haven't even got that far to think about a tank yet. Although it would be nothing for me to weld something up. but most likey those are so cheap it's not worth a bother with the original one.

Heath, do you have any thoughts on a intercooler?
Somewhere once upon a time I saw a passager seat that doubled as a air to water. Really slick if my memory is correct. Wouldn't have been realistic for someone to sit there though.

 

[folkenheath]

The cam is definitely the biggest bottle neck on that engine other than the exhaust manifolds. Although preturbo exhaust isn't as cricitical as after the turbo. Still, a good header is always one of the best upgrades.

I would only use air - water if it was strictly a drag car only, unless you are thinking of having a separate radiator for the intercooler fluid as well? Kind of like they do with the new high helix blowers from eaton(edelbrock, magneson, etc.) Seems like it is getting complicated though since you do not have a small space to cool the air like those setups do. You don't need one of those ice coolers in your interior you have to ice down with cold water every time you want to go fast. I would just use a simple air to air method for what you are building, put an air to air in front of the radiator behind the grill. They probbaly make a lot of units to fit that body style since the GN came with a turbo from the factory. You just need to get one large enough for your hp level so you don't get too much of a boost pressure drop from it or it will cost more hp than it gains.

My brother has an air-water he got used on the cheap on his shortbed with the procharger. If he fills it full of ice water in the staging area it's steaming by the end of one pass, so its not something that will give you gains for long. Obviously larger capacity will last longer, but for a road car you want something that cools itself, which means you would need to either cool that water, or make it simpler and lighter and just cool it air-air.

I have a spreadsheet I wrote to help select turbo size if you want. Just a few inputs will help you look at a compressor map and choose the correct turbos for your hp goals. Or are you just going with junkyard turbos?

 

[beags86]

Ok, I didn't realize a air to water was that short lived. I was thinking that I could fill it before an autocross run and be good, but nevermind.

I'll buy new compressors. So yes, send me that spreadsheet. You have my email.
Thanks.

 

[campfire]

Heath, do you have any thoughts on a intercooler?
Somewhere once upon a time I saw a passager seat that doubled as a air to water. Really slick if my memory is correct. Wouldn't have been realistic for someone to sit there though.

That sounds slick (in more ways than one). Do share pictures if you find any.

 

[Team208Motorsports]

Air to water depends on the size of the cooler it self and the heat exchanger. For what you are doing just stick air to air and if you want a big boost then hit it with meth as needed.

Cam wise, I say upgrade so you can at least gain a few rpm. Even the LS6 cam feels like it hits a wall in the low 6s. The stock 6.0 cam feels that way much lower. It all goes back to use.

Headers get important depending on engine build and rpm range. If you are sticking with stockish....... It all depends on how much you want to do twice. I'd get the entire exhaust done correctly the first time.

 

[beags86]

Use will be a moderate driver. Maybe drive it to work once or twice a week. At most. Saturday/Sunday drives. I'll probably only autocross it 2-3 times a summer. Maybe 2-3 passes down the strip a summer. Maybe a day or two at a open track day at a road track. But not to worried about that right now since I have a road racing Jetta.

So yeah whole lot of time and money for probably not alot of driving.

 

[Tweekls1]

I would put a brian tooley or lil jon boost cam in it, and if you have e85 locally set the fuel system up for it.

 

[beags86]

Yes we have lots of corn juice around here. This is the Midwest...

 

[Tweekls1]

Didn't even think about the fact that its alot more common up there, we only have 2 stations within a 25 mile radius of me.

 

[beags86]

I don't know how many we have, I don't keep track, but there is one ethanol production plant with a gas station out front I buy alot of gas from. E10 for my truck and E85 in my wife's impala. My wife uses alot of E85. Some people say they can tell the difference in the way their cars run. Well maybe in the early days of flex fuel.. but I can't in a 2015.

 

[sreidmx]

Texas speeds 224/228 is decent with boost, I have a friend who made 730+ with a c5z06 using truck heads to drop his comp from 10.5 to 9.5 a Wilson 90/90 manifold injectors, long tubes and a pro charger d1sc at 19psi with meth.. along with a really good tune.. prohargers are another animal compared to terboz and likely would make more power. The ls6 has a better rotating assembly than the 6.0 so that I am sure contributes to the fact that he never killed it.