383ss

iTrader: (14)

I've had this idea in my head for a year or so and finally got in a position where I can start the build. I found a great donor car, an 85 IROC with 130k miles, no rust, fresh paint, 99.9% stock and functional, pretty damn clean car. Got it for a hell of a good price too

anyway, I'm not sure if anyone had tried this specific type of swap. If so I'd like to hear your results/opinions. I plan on using AFM and tuning it agressively. This is to be a DD/cruiser in descent weather. It will probably see a lot of 800 mile roadtrips

my goals in order of priority are:

35+ mpg highway (can you do lean cruise and AFM? if so maybe a few more mpg)
100% streetability
high 12's 1/4
300rwhp


i'm not set on the 6L80, may just go cheap and do a 4L60. I'm not sure how much mpg or ET a 6 will get me. I'd probabl put in a ~3000 stall. Interior/exterior/wheels to remain stock, but will do TACTFUL weight reduction.

Engine will remain stock with headers. May port the heads or add an 6.0/6.2 AFM cam and see how that worksk at some point.


So anyone ever put an AFM V8 in a 'light' car and see what they can get for MPG?



here's a few pics of her. The swap will start when snow hits the ground and be on the road complete when its gone.

V8Rumble

iTrader: (9)

Looks like a pretty nice find - the mileage is fairly moderate for the age of the car, it looks like an uncracked dash pad (which is a good find all by itself!), & I really like the "strobe" cloth pattern that some of the Camaros of that vintage came with.

I don't know if you'll be able to get 35 mpg out of it, but it's certainly worth trying. I'll know a bit more in the summer of '10 when I'm able to drive my own thirdgen project - fuel economy is one of my primary goals as well (although not the primary goal).

I'm thinking that a manual trans would likely be worth a good .5 mpg due to the lower drivetrain losses with a stick, maybe try a TKO unit rather than the T-56 (unless you're going with 4.10s or deeper in the rear, which seems unlikely) simply because it probably weighs a bit less.

Also - unless you do some serious weight reduction, I think that you're going to need more than 300 hp to get into the 12s. Not being critical, just stating a fact - If memory serves, 300 hp should get you down a 1/4-mile track in the high 13s. My engine's rated at 403 hp stock, & I'm not sure if I'll get into the 12s (corrected for altitude). Regardless, 300 hp will make for a fun driver, no doubt about that!

Finally - just on the off-chance that you haven't seen/heard of it yet, there's a decent forum for LS swaps into our cars right here. You probably won't find all of the answers you're looking for there, but you'll probably find a LOT of 'em!

Good luck!

subtlez28

iTrader: (15)

Sounds like you are stuck on the auto route (bummer because a T-56 would better fit your goals). I'm assuming serious surgery would be needed to your 3rd gen to clear a 6L80 (they are huge). And 35 mpg seems like a pretty high goal for a 4l60. That said I will admit ignorance on "lean cruise and AFM".

To put it in perspective:
4th gens like my 02 Z28 get low 13's and high 12's stock. It is pretty much just an issue of traction. So I think the high 12s and 300 rwhp is totally do-able.

I've got a best of 29 mpg in my 02. Again stock, but with a T56. I assume the 4th gens are a little more aerodynamic than the 3rd gens, so the 35 mpg is a tall order. Maybe the AFM could help w that, but the auto will hurt you. I think 25-30 mpg is very reachable. If you get into the 30's that will be great, and you will have some bragging rights. But the difference between 28 and 35 mpg shouldn't make or break any road trip budgets. So I wouldn't get to worried there.

It will be interesting to see how V8Rumble does with his T-56 and VVT. I'm guessing very low 30's mpg. I'm also guessing high 12s when he runs at lower altitude. I'm very excited about TK's car hitting the road. I love GTAs, and my own swaps are moving at a snails pace (though sitting here typing-and not in the garage working is part of the problem).

TK, refresh me, you have 3.42s out back?

383ss

iTrader: (14)

thats why they are goals right? to make them hard to reach.

ya, im pretty much set on an auto. I've never had an auto car before and want to switch things up a bit. Also, AFM is more driveable with an auto from what i understand. With a manual it would be very noticeable when it swaps from 4 to 8.
I know a T56 would be a little better for my goals, but I want to do it with an auto. i also like to try stuff other people haven't and i don't think anyone has gone a MPG biased route on a swap.

as far as my 1/4mi goals, i think the 5.3 should be near 300rwhp with headers, tune and CAI which is pretty much what a 4th gen puts down stock. Plus it should be 2-300lbs lighter. So, i think it will go low 13's and maybe dip into the 12's on a good day.

I didn't realize the 6L80 was that much bigger, i thought it was similar size to a 4L60. I don't want to do any modding to make it fit, so I guess i'll probably just go with the 4L60.

I know 130k on the car isnt anything special, I'm just more impressed with the condition, especially for $2800


Lean cruise is a mode that was available on earlier LSX cars/trucks, but you had to do some code modification to do it. i had it enabled on my 03 silverado and got 2-3 more mpg highway. it allows you to run up to 16.8:1 AFR after 'cruising' for a set period of time. that is around 14% leaner than 14:7:1 so you would get 14% better economy when it engages.
I just don't know if you can or should try to run it when running AFM.

ml258-89iroc

iTrader: (5)

clean car, between this site and thirdgen.org the swap is pretty staight forward. good luck!

Stealthy

That is a nice find, looks to be very clean.

V8Rumble

iTrader: (9)

I would agree with that.


That would be nice - both of those!

You & me both, brotha! Actually, my wife's volunteered today to spend 2-3 hours in the garage helping me to work on the project, so as soon as I'm done typing this up, out to the garage I go!

No, I kind of wish they were 3.42s sometimes. What I have is a slightly-beefed 3.27-geared Australian 9-bolt. While the 9-bolt is a bit stronger (in stock form) than the 10-bolt that most F-cars came with, finding parts is a real PITA, so I'm going to be calling MW (who's not too far away from me) to see how long I'll have to save up for a F*rd 9" - since I don't expect the existing rear to last behind too many launches...