chriss71z28

I was wondering if i could get close to the performance of a ls2 corvette motor by using a lq9 6.0L short block and getting the ls2 heads and get a cam to has the same specs as the factory vette cam to make close to the 405hp that the factory motor has? I would like to do the motor as a carbed set-up. Looking for a street performance ride without getting into all kinds of pricey parts. I want a good running motor so i can drive my car more and enjoy it. I'm new to the ls stuff and have been trying to read up on it more when i find good info. My car had a old school 406 small block that was just too racey for the street with a 350 turbo and big converter. I'm thinking of a 700r4 to cut down on my 4.10 gears for more cruising. I want to get more use out of my car. I know most will say get the l92 heads, but those seem to be more toward hi-rpm performance. I want a nice dual-plane intake for low end torque. I have a 750hp holley now off my 406. Any thoughts on what you guys feeel would be a good route to go would be great. Thanks

69LT1Bird

iTrader: (1)

The LQ9 short block is the same except its iron. 6.0L flat tops etc. Bolt the LS2 heads on and you are ready for the carb intake.

Pocket

iTrader: (22)

Except it uses GEN III cam and knock sensors

69LT1Bird

iTrader: (1)

He said he was getting a cam to match the vette and is going to use a carb, no knock sensors needed.

chriss71z28

So i just have to make sure to have the cam senosr that goes with the ls2 cam then right? I checked the crank sensors and they are the same between the lq9 and ls2. I was going to get the msd box to fire the coils. Is there anything else that i would need to add to this? I belive the 05 and down uses the 24X wheel? Thanks

gofastwclass

iTrader: (2)

Since you brought up money I have to share a bit 'o my own research on this....

Running a carb is not cheaper than keeping the FI setup - IF you get all the FI setup when you acquire the engine. Unless you are dead set on it, I would price the parts you need to go carb before committing to that route. Especially if money is the motivator.

The short list I remember off the top of my head:
Intake
Carb
MSD (or similar) box for spark
Electric fuel pump (either way)
fuel filter (either way)
Transmission control (depending on transmission)
etc.

Of course going LS2 means new intake, fuel rail, injectors and TB (all can be sourced on CL or ebay).

Tuning the FI engine will be different, but the smooth idle, all weather performance and easy starting make the adjustments worthwhile for me.

...Just my opinion... Good luck whichever route you choose.

deelong4002

iTrader: (8)

WHat about Lq9 EFI with a T-56 behind it? Great performance, and awesome gas mileage for a cruiser. I really hope to build an oldschool hotrod with that type of configuration some day. I'm sure its a bit more difficult up front, but the payoff of having dead reliability in all weather conditions, and economy car type gas mileage is worth it to me.

Pop N Wood

iTrader: (1)

GM offered a carb version of the LS2 motor. The only thing they changed was the intake and rated it at 440 HP vs. 405 for the FI motor. so your target HP just went up by 35 HP. But if you go dual plane you may give back that advantage.

Just how do the LQ9 heads compare to the cathedral port 243 heads on the LS2 motor? I thought I read on here that they flow the same. I'm probably confused though.

Since you are going to buy a cam, I would go a little bigger than the stock LS2 cam. The LS2 cam is suppose to be the same as the LS6. With the right cam you will easily be over 500 HP. There are a number of car mag write ups on the subject.

gofastwclass is right that the cost of going carb can add up. But if you factor in used stuff, especially since you already have a carb, then it becomes harder to tell. If you buy new the intake and ignition will run the better part of a grand.

Jim85IROC

iTrader: (6)

Why limit yourself to the LS2 heads? If you've got an LQ9 shortblock, you have a lot of head options. L92 or LS3 heads and the right cam will wake that motor up and are still very affordable, especially considering that you'd be buying heads & intake anyway.

garys 68

iTrader: (1)

I bought an LQ9 with intentions of doing a head/intake upgrade at a later date in my 68 vette. I wanted to keep the vette looking stock externally, so I kept the original tire/wheel size but added a 6 speed OD trans.
Right now the FI LQ9 with a mild tune and C5 headers will eat the rear tires in most gears. When I looked at upgrades, the HP and torque curves would only have a significant increase at 5000+ rpm. For me, it was not worth the effort since I'm not taking it to the track.
Check out this article on a carbed iron head LQ4. A simple cam, intake, carb, and headers (no heads needed) should make your LQ9 do even better and get you well beyond 400hp. BTW, I still have not ruled out a cam change, but I would need an LS6 intake to make more hp.
http://www.carcraft.com/projectbuild...ock/index.html

chriss71z28

Good thoughts guys. On the fuel system, i already have a mallory comp140 elec pump, a factory sumped gas tank and #8 feed and return lines. The holley 750 hp i have is pretty much brand new. So i have the whole fuel system already covered. To me it seems like the L92 heads are for more power up top and you can only get a single plane intake for them. With my old 406 small block single plane intake meant crappy low end torque. I don't want anymore huge cam and carbs that load up in traffic. I want good power for street performance and to be able to enjoy the car more without screwing around all the time. The dual plane intake is only $260, the msd box to run the timing is around $310, LS2 heads i can get for about $500 for the set and then whatever cam i go with. The trans is going to be a 700r4 or 200r4 so i don't need any controllers for them. I'm trying to go with a basic installation. Car doesn't have any a/c so i don't need any of that stuff either. Would i be better off with the factory heads and do some porting on them and clean them up? I appreciate all the info guys. I'm still new to this gen motor and all the guys i know are older and don't have any idea about this motor.

bozzhawg

Sorry Bozz, but the 700r4 or 200r4 do not use a TCM(transmission control module).... They work off a detent cable that would be best mounted off the throttle body.... With that said, you would have to convert to a mechanical throttle body/ cable throttle body with a detent adapt..... The factory heads 317's are not bad with some port work and shave em down .010-.030 to around and you would bump up and gain some compression as well...... A lot of people don't like the bone dry unmoded 317's because of the chamber size 72cc ....

Also check and make sure your 05 LQ9 is a 24x reluctor..... Between 05-06 is where GM started phasing in to 58x reluctors and DBW on all LSX motors .... Its weird, like the 06 GTO and SSR LS2 were 24x reluctors but the 06 vette LS2 58x reluctors......... There were a lot of mixing and matching during these to years...... Just check first.....

Jimbo1367

Good point. What was the color or the cranck sensors for each again?

1970camaroRS

iTrader: (8)

It IS cheaper if you already have a carb setup and an electric fuel pump like me. All I needed was an intake and ignition control and the parts to adapt my 700r4.

tonyy33055

waz up boys. i have a lq9. yes its not a lq4, it came off an 2006 escalade AWD. the motor is all there from the fan to the AWD tip. no WIRE HARNESS tho... so should i just do the jegs MSD carb setup or should i try to keep lookin for the HARNESS and do FI????

chuckd71

iTrader: (23)

Harness + FI.

tonyy33055

so FI be better

tonyy33055

waz up boys

lamdenali

iTrader: (5)

Absolutely

psiconversion

iTrader: (5)

FI!!!!

Jon
PSI