TransAm Mania

iTrader: (7)

I'm planning on swaping in an Lsx into my 79 TransAm and I woul like to go with a turbo as well. Would it be better to go with an LQ9 or an LS1 with a forged bottom end? I want to go with a T 56 6 speed so will that work with the LQ9? What kind of internals are in this motor, forged or cast crank and pistons. Also, What can I do with the computer for this motor to get more performance out of it, in other words more F body oriented as opposed to pickup truck friendly.

stealth71

iTrader: (15)

What are your horsepower goals?

pist0lpete

iTrader: (3)

The stock crank on LSX style engines has been proven to safely hold over 1000 horsepower so unless you are planning on going beyond that the cast crank should hold but forged is not a bad idea. As far as blocks the LS1 is fine if you want to run no more than 10 or so psi of boost. Much beyond that like say 20 plus psi the ls1 will experience cylinder wall distortion so you would be forced to sleeve the block which is expensive. The Iron blocks will safely handle more boost in stock format. Of course you would definitely want to go forged on the pistons and rods.

98Z28MASS

iTrader: (6)

LS1 forged bottom end hands down. Iron blocks are nice but if your talking about a stock Lq9 block and bottom end versus a forged ls1 short block then there is no comparison, ls1 all the way. Plus if weight is an issue the rion block will be heavier than the aluminum ls1. I say forged 346 ls1 shortblock as people have run 15+ psi on forged 346 ls1 blocks, and that would be good for 650+ rwhp. As for the computer all you will need is a local shop that has hp tuners or efi live for lsx engines and have them fully dyno tune it.

'JustDreamin'

The LS1 with all the forged goodies would be the obvious choice.

HOWEVER, its also the much much more expensive choice. I'd bet an all forged LS1 is an easy $3k to $5k more than a stock LQ4 or LQ9 (haven't priced one out recently).

The LQ4 or LQ9 with forged rods and pistons would probably be just as stout and a whole lot less expensive (but weigh 80lbs more). As mentioned before, the stock cranks will live at 1,000hp (boosted, not NA) so unless you've got money to burn or want more displacement, why spend $1k on it? Fix the obvious shortcomings (rods and pistons) and put the money you save somewhere else.

Just my $.02

'JustDreamin'

TransAm Mania

iTrader: (7)

Ok. Did a little more research on LQ4 and LQ9 motors. The LQ4 has lower stock compression which would be better for a turbo but the rods are not as strong as the LQ9's rods. Does any know if the iron blocks have the same accessory location on the front for say alternator and power stearing pump? The reason I ask is because I worry about hood clearence and such. I assume the bolt pattern will be the same for the tranny so I can use the T56. Now what about heads, which ones would work the best with a turbo?

CrawlinWS6

iTrader: (41)

A forged 408 is def the way to go!!!!

TransAm Mania

iTrader: (7)

Thanks crawlin, I know your forged 408 all the way but I want to hear what other people have done. I want to get this car on the road as soon as possible and that is a long way off as it is. If I can go with a stock LQ4 with mild boost from turbo and get respectible HP, I'll be happy. That way I can build up on it gradually. BTW you still got those heads from your Ls1?

'JustDreamin'

Hey Boss.....

The heads on the LQ4 / 9 are pretty decent. They're typcially #317 castings, which are basically the LS6 head with a bigger chamber (70cc instead of like 62cc). Other major difference is the LS6 heads run lightweight sodium filled valves.

The LQ4's have a couple of things in their favor.
1.) Cost. You can score complete motors for a bunch less than the LS1. I picked up a complete 26,000 mile 2004 LQ4 for $1200. Runs great.
2.) Bore size. LQ4 is 4.000", LS1 is 3.9". Bigger bore = less shrouding of the valve = better breathing potential.
3.) Block strength. Basically the block is the exact same, but iron is stronger and more stable than aluminum. Will put up with more.
4.) Block can be overbored. You can punch a LQ4 out .030" or .040" to clean up the bores, but the LS1's are limited to .005 or .010" due to the thickness of the sleeves (which the LQ4's don't have).

The truck accessory drive package is different. Its further away from the block (like 1.5" or so) than either the f-body or vette accessories. None of the actual accessories interchange. But you can put f-body access on a truck motor (just have to swap balancers).

Something to ponder: The L92 heads are out, and there should soon be a car type intake manifold (the L76) readily available. Stone stock L92 heads flow about the same as the AFR 205 heads, meaning they've got a fair bit of potential. You might want to sandbag on your engine plans and wait for that stuff to get sorted out some. It looks like it could be the next big thing. The L92 truck motor is rated at 403hp / 417 ft-lbs (with a truck type cam and truck type intake, ie tuned for bottom to mid range power, not a high rpm screamer). Just a thought.

'JustDreamin'

CrawlinWS6

iTrader: (41)

I sold the heads last week!


And hell, you have enough room to throw in the gm crate motor "ram jet 502"!

TransAm Mania

iTrader: (7)

How much boost do you think I can run with the stock LQ4? Do you think I would need to change the cam to get higher rpms with the turbo?

G-Body

iTrader: (4)

The truck motor would probably be your cheapest option. Don`t worry about the computer programming, HP Tuners or EFI Live 7 can fix that.

I have been playing around with Desktop dyno the last few days and it looks like a 6.0L with a cam and headders will put out around 500hp/500ftlb. And thats with a GM cam. Check out the attachment

EDIT: Just ignore anywhere on the desktop dyno stuff where it says 5.3L, I updated all the specs to 6.0L stuff but forgot to resave it.

'JustDreamin'

I chatted with the folks at STS since I've considered doing a "mid-mount" setup on my truck (which has a stock LQ4 in it).

The stock pistons are the boost limiting factor. Pistons are really only good for somewhere in the 6psi range. Much more than that and they become a liability. The stock rods should be good for more than that, but not all that more.

I'm sure a cam swap would wake up the LQ4 a fair bit. But, if you're going turbo, you shouldn't get to radical. I understand the LS6 cam is pretty good, I'd expect the ASA cam is to lumpy to work good in a turbo (but I'm guessing). I thought about changing cams when I put the motor in my truck, but between the cost of the cam, fresh springs, and better pushrods, I decided to wait and just get the truck running with the stock motor.

'JustDreamin'

'JustDreamin'

That's pretty cool. I may have to see about getting a copy of desktop dyno.

I'd be real interested in seeing what the 6.0L would do with the new L92 heads (flow numbers are in the LS2/7/92 section, intake flow is like 330cfm @ .650" or something around there) with a cam like the ASA cam. Would you be willing to throw the L92 head data in there and run the simulation again (keeping all the other parameters the same)?

'JustDreamin'

76LQ9TA

iTrader: (1)

That looks like my car in August. I have put a LQ9 and 4L80E trans in a 1978 trans am. I have the engine and trans in the car. I am still working on getting it to run. Waiting for parts right now. I have the wire diagrams for the 02 escalade that my engine was out of if you need any information on the wiring. I had pcmforless reprogram my computer for the trans and fans. I am going to get this setup running and then change the cam. I am getting my radiator from Rodney Red in IN. I am using the electric fans from a 99 trans am. You should try and find all of your exhaust before you choose the engine mounts. Depending on what you do for AC you can have the engine forward or back by 3 inches. I have drawings for 2 types of mounts and have one set I am not going to use. It worked for the short headers but not for the long tube headers I found. One other thing I ran into was with the weight of the engine. It must be alot lighter than the pontiac 400 because the front of the car sits higher. I will probably have to cut the front coils. Tamraz in Plainfield has good prices on suspension parts. I can also give you the GM part numbers to install 98-02 rear disc brakes on your car if you have the drum brakes. The only bad part about this setup is they will not clear the snowflake rims. I used ROH ZS 17" rims. Have you modified your gas tank? I used the Tanks Inc setup with a Walbro 255 lph pump and ran Parker fuel lines.

TransAm Mania

iTrader: (7)

No haven't modified the tank yet but whats involved in dooing that. Drawings of the mounts would be cool if you could post them. That sucks about what you said about the coil springs. Those things were a bitch to install using crap *** Murry's lonner spring compressor. Not to mention I have a fear of springs! I got a spring from a seat track stuck in my eye once. It poked through my lower eye lid and got hooked behind the upper eye lid but didn't puncture the eye itself. Need less to say, I was not wearing safty glasses.

76LQ9TA

iTrader: (1)

The first mount has the chamfer in opposite sides for left and right. This is what I am going to try to get the FLP headers to fit. The next set didn't get the engine back as far.

Do a search for "Tanks Inc." for the fuel pump. To install I bought a 4.5" hole saw and cut into the top of my new gas tank. It has a small pan to hold the fuel around the pump. Their site has pictures. I ran parker fuel line to a filter I mounted on the subframe connector and up to the engine along the driver's side. Return line also along the driver side. I may have to switch the manifold to clear the hood. I should know in a couple of weeks. Going to my job gets in the way of working on the car.

G-Body

iTrader: (4)

I gave it a try, but it only increased power a little. Nothing like I was expecting. Mabey the ASA cam is too small to keep up with the higher flow heads?? I`ll try throwing some bigger cams at it in a couple days when I get some extra time

Cop Car

iTrader: (14)

i think you could boost like 8-10 psi on a stock LQ4

LS1s are way overpriced, get an LQ4 and put forged pistons in it and you can see 800rwhp reliably

'JustDreamin'

This is so off-topic that it's not even funny, but I appreciate you taking the time to throw it in there.

I'd expect the power isn't there for a couple of reasons.
1.) Exhaust flow numbers are weak compared to the intake, probably needs more duration on the exhaust side.
2.) The ASA cam is only like .525" lift, these heads are peaking at like .600. I'd say it needs more lift (probably a combination of cam & rocker ratio in real life).
3.) I'm not sure if it matters for the simulation, but the valve sizes are 2.16 and 1.59 for the L92 heads. I don't know how Desktop Dyno works, so that may be a mute point.

Anyway, thanks for humoring me. If you get the chance to play with it some more, please post up the details....Or PM me with em....

EDIT: I just compared the two files again, and there's something a little weird there. Both indicate 500 ft-lbs @ 4500 and 512hp @ 6000. I'd expect changing cylinder head flow rate by 50 or 100 cfm would have an impact (either negative or positive). Dunno.....

'JustDreamin'