Chevy Impala SS Forum banner

21 - 40 of 43 Posts

·
Registered
Joined
·
1,761 Posts
My main point was that finding someone to tune LT1's is very difficult to do. Keeping cubic inches near stock and getting a head and cam kit from the well known providers makes for a setup that can be tuned fairly accurately by mail order. However, there are aftermarket PCM components that alleviate the tuning issue. Of course, there are costs associated with that as well. Also keep in mind there are many cars out there with strokers and aftermarket heads that are outperformed by simple cam/head swapped cars running stock bottom ends. Many have the mentality of stroker-or-bust but a lot can be accomplished on the stock bottom end.

I have nothing against supercharging, turbocharging, or the use of nitrous. It just makes LT1 tuning far more difficult than it already is. If you know how to do it yourself, know someone who can help, or go to a Torqhead setup, the tuning issue isn't a problem. Finding a quality forced induction kit is nearly impossible for these cars and will likely require extensive fabrication ($$$$$.)
 

·
Registered
Joined
·
1,475 Posts
I have nothing against turbos, superchargers, chemical supercharging, or precompressed air supercharging.
I still have this inkling that the LT1 does not like 'very-high-dynamic-compression' …

Karl Ellwein is probably going to become a major 383 / 395 / 401 tuner.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #23
Tuning is always gonna be key. You can have a beast but if its not tuned properly it will be a load of crap. Agreed that it's hard to find a good tuner for the lt base and as time progresses, most of the younger guys will be on an ls system. The fact that I do plan on keeping the car another 20 years or so, I should get on a platform that will be more familiar with those techs.
I have no issue with prochargers or turbos but will stay away from nos cause of mainly dd. The 6.0 motors are better than the older 5.7 and better than the 6.2. Now... which one would have good endurance and not too much overhauling.
 

·
Premium Member
Joined
·
20,284 Posts
…...I still have this inkling that the LT1 does not like 'very-high-dynamic-compression' ……..
Optimal DCR for the LT engines seem to be in the 9:1 to 9.5:1 range.

Optimal quench of .035" plus 9.5:1 DCR is VERY doable.

KW
 

·
Premium Member
Joined
·
20,284 Posts
…….The 6.0 motors are better …...than the 6.2......
Only if you consider the heavier iron block to be 'better' than the aluminum block.

In any case, I would endorse the rectangle port heads/intake versus the cathedral port heads/intake.

KW
 

·
Registered
Joined
·
233 Posts
Discussion Starter #26
Only if you consider the heavier iron block to be 'better' than the aluminum block.
Is the 96 model the last year of the iron block
 

·
Registered
Joined
·
1,475 Posts
Is the 96 model the last year of the iron block?
For the LT1, 96 was the last year for iron block AND iron heads. For the LT1, 97 was the last year for iron block and aluminium heads.

As for the Gen3 & Gen 4 V8s, if you can work this table, you'll know which engines from which years were available with iron blocks. Looks like 2008 was the last year for iron heads.

Gen3 & Gen4 V8s are so durable and reliable, that unless you plan on unusual amounts of boost, an aluminium block is fine.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #28
Gen3 & Gen4 V8s are so durable and reliable, that unless you plan on unusual amounts of boost, an aluminium block is fine.

👍👍 I'd probably put maybe 5-8lbs of boost which should be an additional 220 hp. Would that be safe or would it wear out the engine faster
 

·
Premium Member
Joined
·
20,284 Posts
…...I'd probably put maybe 5-8lbs of boost which should be an additional 220 hp. Would that be safe or would it wear out the engine faster
95impala…..there is a "Quote" button lower right corner of each post. For clarity, when you want to quote a previous post, just use that button.

As for boosting an aluminum block, LS engine.....guys have supercharged the LS3 engines and are still rollin' after 50K-plus miles. Magnuson makes a LS3 SC that a LOT of Camaro and SS guys have gone with.....with 6psi boost. NO PROBLEM.

And....the GM LS9 (SC'ed) engine is also an aluminum block....it came making 10.5 psi out of the factory.

So.....yeah. The aluminum block will hold up under low/moderate boost.

KW
 

·
Premium Member
Joined
·
20,284 Posts
Thanks for the info.
Is supercharger on the ls aluminium motor better than a turbos?
No idea.

But as far as I know, there are no off the shelf turbo kits available for the B-body.....or the LS engines. So if you want to go turbo, you'll need to have someone cobble together a set-up for you if you want to go that route.

KW
 

·
Registered
Joined
·
2,312 Posts
Thanks for the info.
Is supercharger on the ls aluminium motor better than a turbos?
What KW said. To add to it, turbos, IMO, are superior in regards to making power. More efficient, no stress on the crank snout from blower belt tension, adjust boost on the fly and make more power per PSI than a blower.

With that said, it is a more complex system with more parts and more to go wrong. The plumbing and turbos may cause under hood temp issues burning up sensors and what not and make maintenance and repairs more difficult. Just more hassle and clutter IMO.


I'd strongly suggest looking into an LSA supercharger. Complete kits can be had for about half the price of most other superchargers. They aren't ideal if you are shooting for higher power levels like 650+RWHP but guys DO take them to 750RWHP and beyond without issue routinely, it just takes a good supercharger cooling system and good fuel.

There are handful of LSA powered B bodies out there already, so there are formulas to follow as far as the swap goes and it doesn't really require too much custom work to make it fit. Cheapest possible combo would probably be an LQ4 truck motor and an LSA blower. 500HP at the wheels and if you shop around right you could probably find the motor with low miles for 2-3k then another 3500-4500 for everything you need to get the blower running on it. From there, you'll still need a fuel system, headers, exhaust, conversion mounts, conversion harness, ECU, tuning. Then your transmission will likely be on borrowed time. You see how it adds up, even doing it the "cheap" way like I mentioned about will probably end up in the ballpark of 10-15K and that's using a lot of used parts and shopping for deals. Go with a built for boost motor and a procharger/magnacharger/whipple and you'll be looking at closer to 20-25K depending on how crazy you go.

I'll be completely honest, you have to WANT the b body if you still want to be competitive out there. There used to be a time when a few bolt ons or a 5K budget built stroker motor put this car in a league with newer cars, but newer cars have took off tremendously in the last decade or so. If you're a real junkyard hero who doesn't mind living on the ragged edge, you could cobble together a turbo LS setup into a B body for a reasonable price, push it to the limits and run with Hellcats. If you're looking to build something reliable with new parts that can keep up with some of the big power cars out there, you are likely spending as much as a sizable downpayment on one of those new cars to only MAYBE keep up with them STOCK.

I've got a $7500 motor, $5000 supercharger setup, $3000 trans/converter, $800 rear, $2000 fuel system and god knows how much in supporting mods/suspension into my SS project. Probably a conservative estimate for what I have in the car now is $30K and the car still needs paint/body work and a new interior and this is me doing all the work myself, no labor costs. if I can make 700RWHP reliably with it I'll still get walked by a Hellcat with a pulley swap and the built comes damn close to the cost of a used Hellcat, which is a far superior car in just about every way possible than my B body even with all the mods.

But I love B bodies, and I made a choice when I started the project that I'd rather roll up to a car meet in a beast of a B body than a "me too" car.
 

·
Premium Member
Joined
·
20,284 Posts
......There are handful of LSA powered B bodies out there already, so there are formulas to follow as far as the swap goes and it doesn't really require too much custom work to make it fit. Cheapest possible combo would probably be an LQ4 truck motor and an LSA blower. 500HP at the wheels ......
IMO....if you're looking forced induction and your goal is 500-550 hp at the wheels, a H/C LS3 with 'smart' bolt-ons would be the way to go.....simpler and IMO, more reliable.

My LS3 has a 'medium' performance cam. Yes.....I could go a lot bigger, but then I'll be sacrificing ride. No desire for that since this is my daily driver.

My built 4L60 has held up for 3 1/2 years with this engine. As long as you don't constantly stomp on the 'go' pedal, the tranny should last a long time. But this is true with ANY engine set-up in front of the 4L60E.
KW
 

·
Registered
Joined
·
233 Posts
Discussion Starter #34
SSandman great write up in detail. As much as I plan on keeping my ss, I cannot justify spending over 15k on it at the moment. I have family priorities. I can do little by little and eventually get everything in order at a later date.
I agree with you that vehicles have come a long way in the past decade. That's one reason I was holding off to do a swap. There are more vehicles with more options and the price are cheaper.
As far as wanting the power to say I got xxx... I'm not that guy. Havent even been to any car meets or shows for that same reason. It's good to meet new people and create new friends which can help out with knowledge; I'll probably do later on.
I may as well just put this on the back burner until I got everything in order as well as having the cash to implement it.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #35
KW I was replying to SSandmand while you made that last post.
550 is more than enough power for me. I'm not taking on the track. Will be doing some Florida Georgia driving which is about 6+hrs straight. As long as the car can handle that run about 4 times a year, I'll be fine.
 

·
Registered
Joined
·
1,761 Posts
SSandman really summed it up. The cost of making big power on a 25 year old platform approaches the cost of buying a used Hellcat Charger or even better in my opinion: a used CTS-V. My car would likely get smoked by either of those in stock form. And that includes street racing, drag racing, top speed, handling, braking, etc.

I just took my car to a local show over the weekend and my car got far more attention from spectators than any of the hellcats, mustangs, CTS-V's, Camaros, etc. Nearly anyone with decent credit can buy one of those cars and there are usually 10+ of each of them at our local car events. I have only seen ONE other B-body at our local events over the past several years. I don't like being mainstream. FACT: there were more Lamborghinis at our meet this past weekend than 1958-current Impalas. I'm not saying an Impala is even in the same ballpark as an exotic, I'm just saying I like having the only 1 of something at a car event.

If you are in it for all out performance per dollar, get something new. If you are like most of us on here and love these cars, I'll go back to my initial advice to swap the cam and heads on your existing bottom end (if it's in good condition.) It won't be fast by today's standards but it will sound good and will be fun to drive without spending 4x what the car is worth...
 

·
Registered
Joined
·
233 Posts
Discussion Starter #37
If you are in it for all out performance per dollar said:
Might as well but how much torque will I have to tow because that was one of my main purpose of redoing the motor.
 

·
Registered
Joined
·
2,312 Posts
I agree with everything said above.

You really have to set a power number goal with a minimum HP/ET you'd be happy with (you might have, I just didn't skim back through the thread to find it). I mean if you just want to be a little faster, it's possible you'd be fine with a full bolt ons/1.6RR LT1. If you want to a Coyote mustang, you'll need a lot more.

The reason I suggested forced induction like the LSA blower on something like an LQ4 is because IMO, you can maintain the most possible streetability and reliability while making the most possible power. A blower on a stock truck motor, as KW pointed out, won't make much more power than a well built LS engine but you'll be making the flattest possible torque curve and have the most off idle power for towing (it is a truck motor after all, assisted by boost). There are trade offs, like the tuning is critical with boost, but there are also benefits over lets say strokers or HC engines like no accelerated bore wear from accelerated piston speeds, no need for high RPM's to make the same power a smaller cube N/A motor, no need for big cams that are harsh on valve trains and there is a little bit of comfort IMO of knowing you have a GM mass produced engine. Very rare to have machining or assembly errors or defective parts versus what I have seen over the years with aftermarket builds. Everything mentioned though from HC LT1 to built LS3 are all viable options though and all have their perks/downsides.

As far as N/A setups go, most things you'll do to a motor to make more power will also shift your power curve up to a degree, lose you off idle torque and reduce towing manners. This is the issue you fight when trying to make power N/A, and that's why I'm saying you really need to figure out out what the lowest power number you're willing to accept is and how much you are willing to spend. I'll throw out a few combos off the top of my head in order of cost and what I see the benefits/downsides as. These are just my opinions and numbers could definitely vary from my guesses lol

1) heads cam LT1: Cheapest option. Lt1's make great off idle grunt for a small motor. probably want to refresh the stock bottom end unless you have some super low mile LT1 lying around. Good set of AI or LE heads and a smaller cam for towing manners You won't make a ton of power, maybe 375WHP. You can make more depending on how much you are willing to sacrifice on the towing manners part.

2) LT1 stroker : cost for this is probably very close to an LS swap depending on how you build the stroker (forged, cast) and what engine you use for your swap/how much of it you do yourself like wiring. More cubes=more torque versus the heads/cam LT1. Better towing manners, more power, tons of torque. You won't see a lot more RWHP over heads/cam, I'd imagine maybe 25RWHP when trying to keep the cam a reasonable size, but did I mention lots more torque? More cubes allow you to move more air without having to turn more RPM's to do it.

3) bolt ons LS swap: too many options here to really go over, so many different engines to choose and I really can't comment too much about potential power numbers on the ones I don't know too much about, but all I will say is you are best off sticking with a larger cube (6.0 or 6.2) variant for more torque. An LS3 with bolt ons will make damn near what an LT1 stroker would make and will still have a great torque curve.

4) built or HC LS swap: probably the 2nd most costly next to the LSA/truck engine combo I mentioned and potentially even more costly depending on how crazy you get. I mean you could end up 8 grand deep into a forged LS3 based 4xx+ CID stroker and probably make 500+RWHP with more than enough torque for towing but then you also have to factor in the cost of the swap. Just my opinion, but I'd say even with a very stout/well put together stroker, 500RWHP is probably going to be about your limit for what you could do while maintaining very good towing manners.

One thing I will say is that it's not that you CAN'T tow with any of these setups. Even a heads cam Lt1 with a huge solid roller making max power will produce far more peak torque than your current engine, but maximizing efficiency for the driving you plan to do is key. Say you build a peaky HC 350 with a big cam and make 400RWHP. You're not going to have much off idle power, you'll have to wind it out a bit to get it going. It's not going to like having a low stall speed on the converter, but a high stall is going to be miserable to tow with. You'll want more gear in the car to get it up into its power curve quicker but more RPM's isn't a good thing when cruising on the highway.

compare that to say a big cube stroker with a small cam or a supercharged motor with a stock cam and you'll have plenty of off idle power, you won't need steeper gears or a bigger converter to go fast and you'll be able to haul a load on an incline at a low RPM without lugging the motor,
 

·
Registered
Joined
·
2,312 Posts
Just one more thing LOL

N/A is obviously a simpler system with less to go wrong could cost less depending on how far you go with it.

with that said, don't fear the boost either. There was a time when making HP with boost was expensive/unreliable. You needed exotic fuel systems to support it and lots of tuners out there burnt your motor while burning your money.

These days things have come a long way.
There are drop in, in tank, reliable fuel pumps that can support a boosted 550RWHP through stock fuel lines.
Later gen LS ECUs like the E67 were designed to accommodate boost, plenty of great LS boost tuners out there
The factory BUILT mass produced, warrantied, 100+K mile 580 and 640hp boosted LS engines.

Aside from the initial coupler issues the LSA blowers had that could be easily fixed (and was never a functionality issue, just an annoyance) the factory superchargers have proven to be very reliable as are the motors they were bolted to.

Sometimes a simple N/A setup is the way to go, just trying to say don't be afraid of boost either. It's not the black magic it used to be requiring exotic parts, hard to find tuners and lots of upkeep/maintenance. Check out the LSA swap Facebook group and you'll find lots of guys who were able to (relatively cheaply) swap in reliable LSA supercharged setups into their cars and trucks. You just can't beat the power curve and street manners a roots blown setup gets you.
 

·
Registered
Joined
·
2,312 Posts
and I know I'm pushing this LSA thing hard LOL not trying to put down the other options, I just personally think an LSA is what this car should have came with haha
 
21 - 40 of 43 Posts
Top