96lt1m6

iTrader: (31)

This cam has been on the emissions friendly list since the late 80s LPE was known for smog friendly go fast parts and still is. Go for it!!

LT1383Z

The LPE 211 and Crane 227 are both great cams and you would be happy with either, that being said I would still go with a custom grind to take advantage of what's been learned over the years.

SS RRR

iTrader: (2)

Phoenix'97, it's more expensive, but if you don't want to have to mess around with a tune or worry about passing emissions/etc get yourself a good set of ported heads and 1.6 rockers with the stock cam. Shift points will be the same so you don't have to alter them with a tune and you can run exactly what you have now and have a significant power increase.

96lt1m6

iTrader: (31)

Can't beat proven advice, results are rewarding

Phoenix'97

Again this is all research in advance. I have been back and fourth asking the same question pretty much and with other ridiculous ideas to modify my motor but with undesired results.

I will have to talk to the shop that will do this work and then arrange for the motor work with another business. If it is really better for me to keep my 5.7L LT1 350, I will gladly spend that saved money to have her done right under the requirements I am asking for.

I am listening to all of your advice and carefully considering what I can do. What I am asking for is the most performance I can get out of my LT1 without killing my motor's rated fuel mileage, daily driveability, and while being emissions compliant, INCLUDING the plug-in OBDII inspection.

I have my heart set on the higher 2.73 rear axle gear ratio, but I wish I had some drive along video to see just how "bad" driving around town is with this gear. If it's merely just a matter of the tachometer taking it's dear sweet time to reach higher power range then it shouldn't be an issue for me, that is really the ideal set-up I am looking for with my kind of driving.

Phoenix'97

If I decide to go with the ported heads and rockers, but I still have my heart set on a different cam, now probably a custom grind modeled on the Crane 227 with emphasis on stock cam emissions if at all possible, and I assume the necessary tune, would this better suit my desire to maximize power potential within the restrictions of mileage and emissions?

Phoenix'97

Checking out other forums on the internet, they strongly advise against ported heads on a stock LT1 cam. I figured...

joelster

What shop are you planning on going with?

Phoenix'97

A local custom shop, they work on the classic cars and they work on newer fiberglass body cars. They work on boats and motorcycles and jet skis.

Hey, they may not be Foose Design or Count Customs, but why spend the money to truck my car out-of-state? God forbid it gets in an accident, the trailer overturns, or it gets stolen. So, if I keep it local, it saves me money and I can check in on the progress with this planned restoration-modification. The work of these guys on their website leaves me with little worries.

Since I am not putting any blowers on my LT1, I am just going to stick with resurfacing of the heads with upgraded valvetrain, and then a custom grind with power, fuel economy, and emissions in mind. Apparently from other forums, I can have my cake and eat it too with a custom grind that will give better performance over stock, likely with more lower-end and even mid-range power, without being too wild.

Now, if I can find a video of an M6 f-body driving with a 2.73 rear axle, I will have a better idea of what I will get myself into. Or, to go with a 3.23.

SS RRR

iTrader: (2)

I have no information on what the 227 has done before, or have forgotten. It too would most likely work with cats, but you're going to want more gear than 2.73's to take advantage. I had 4.11's in my car with the 211 cam and switched to 3.73's after figuring they were slowing me down, which they were. With an auto car you'll want a 3.42 gear, IMO. Your gas mileage will not suffer once you get used to the power and keep your foot out of it. I went from a 3.73 to a 4.56 gear with my last setup and my MPG didn't budge when driving in similar conditions.
Get them and prove them all wrong.

joelster

I live 5 minutes from you, that's why I asked about the shop. There really aren't anymore local shops that can tackle an LT1, specifically the tuning.

Phoenix'97

Well, anytime I mention a business on this site the name is moderated and given a juvenile name in it's place. It's part of the forum posting rules I suppose, if the business does not contribute to LS1 Tech, it's name will not be mentioned when you have contributor names who clearly are advertised.

I can give you some hints if they won't be tinkered with too. It is in Tonawanda and it's name is spelled almost the same as the last great Republican President during the 1980's. They do claim to be able to do custom work, not just mechanical "auto restoration" like other shops I searched. I found this place by chance but I have not talked to them about the plans I have and the work I want done on my car, it's years away as I am in college right now seeking a career change.

As for tuning, in North Tonawanda, there is a place going by the name of a famous Democrat President during the 1960's. They perform dynotunes. The name should be easy to find in a google search with this provided information.

Phoenix'97

Well, this is where striking a balance comes into play between my daily driving experiences which seldom permit me the chance to have fun with my car in bumper to bumper and constantly changing stop and go traffic. I spend more time driving my car in the lower RPM range and wearing out my clutch in this kind of driving! So, taking this real life aspect into the modification of my car, the 2.73 gear seems like it is the obvious choice, although with my shifting habits of keeping my car driving below 2,000 RPM in the city, I am not sure if I am going to bog down my motor when shifting at 2,000 RPM into second, which may put my motor below 1,000 RPM and now I am just lugging her. This is where I should maybe err on the side of caution and go for the 3.23 gear so that my shifting points will be more predictable and I will still have some acceleration where I need it. I found a video on youtube with a 6 cylinder manual Mustang using the 2.73 and then upgraded to the 3.73. I really feel that the higher gear range is suitable for my driving experience and intentions for my car.

As far as the ported cylinder heads, if the heads already flow well enough for naturally aspirated motors and the difference I am going to see if racing the 1/4 mile would be .5 seconds or so, the money to have those heads ported is not going to justify it, ESPECIALLY when all I am doing is seeking low-end to mid-range power to throw me in my seat for occasional short launches from a dead stop or when entering the expressway, or to aggressively pass cars driving 45/50 MPH on the expressway!

I am merely trying to get more power out of my motor within the restrictions of keeping it seemingly stock from an emissions perspective and fuel mileage perspective. It can be done since camshaft design has gone through a serious technological improvement from the late 1980's and early 1990's designs, so sayeth the other forums. I can get my performance increases while keeping the cam within the stock specs, almost, but only from a custom grind. To spend the money on head porting would be a waste for a naturally aspirated motor that won't see any strips for racing!

SS RRR

iTrader: (2)

It's quite possible these days. There's a sticky dyno thread at the top of this forum which may be worth looking at as a reference. As far as gears, I forgot about a 3.23 ratio. Not sure how that would suffice with the two cams which are pretty much referred to as RV cams. Meaning they produce Nebraska Oak pulling torque at low rpm and have a short power curve. If it were me with an auto I'd live a little and go with a 3.42. Your acceleration with the torque produced at low rpm will be outstanding.

bowtienut

iTrader: (1)

Agree 100%. No downside whatsoever in 3.42's with the A4. It's the perfect daily driver gear for anyone who likes to feel a little bit of performance at the same time.

Phoenix'97

I don't have an automatic transmission, I have the manual 6-speed. So, again, there is controversy behind my decision to go with "too high" of a rear axle gear. The way I drive my car, it spends most of it's time below 3,000 RPM and when I do get the chance to let loose, it has reached 6,500 RPM and then requiring shifting to the next gear. I would like to keep it in that one gear and when shifting to cruise at the 50-65mph range, I would prefer to be in lower gears for ease of shifting and less shifting. Plus, this should net me marginally better fuel economy, even for city driving if I can keep the motor consistently below 2,000 RPM when shifting. The custom grind cam, valve-train upgrade, and tuning of my factory PCM to really capitalize on my set-up, could have me approaching 6.2L LT1 rated economy which will make this all worthwhile for me, despite the not-so-impressive power output, but this is not about bragging rights. This is about making it worthwhile to keep my 5.7L LT1 and doing it in a cost effective way versus swapping in a new motor.

SS RRR

iTrader: (2)

I'm confused. Did I miss somewhere that your car was once an auto? Reason I ask is 97 M6 cars came with a 3.42 gear ratio. And no, a lower ratio gear does not mean your gas mileage will improve.

Phoenix'97

Once upon a time ago my first car was a forest green 1997 Firebird 6-cylinder with an auto. I traded up to a V8 with manual 6-speed. Yes, it is currently a 3.42 rear axle, but I am not happy with it granted all the shifting I do to keep my RPM down. I don't like driving around town above 2,500 RPM sounding like a brute, making too much noise, and my car does not have the horsepower to match that noise I am making! So, I keep her quiet and drive like grandpa but my city mileage benefits from it.

Now, I have read all the opinions of M6s using higher gear ratios and yes, for highway it will bump up your mileage, if you keep the RPM down! From driving around town in lower RPM, the 2.73 gear ratio should better help me keep my RPM below 2,000. In playing around with a gear ratio/transmission speed calculator, I should be able to get away with using the 2.73 without problems of lugging my motor, I have mastered the feather foot technique.

SS RRR

iTrader: (2)

There is a huge misunderstanding when it comes to RPM and fuel mileage. There may be a slight influence with RPM variation, but the largest factor in fuel consumption is how much load is on the engine. If you put a lower ratio gear on the driveline it will put more load on the engine especially at lower RPM. Don't take it from me, if you want to try it, knock yourself out, but in order to take advantage of even a small profile cam for both power and running efficiently you want a gear ratio to accommodate. I think you'd be better off just staying with the 3.42. If you go out on the freeway with a 2.73 ratio you may find 6th gear is useless and you'll have to shift into 5th to go up slight inclines. At 60mph in 6th you'll be at 1000RPM. Hardly sustainable at that speed even with an RV cam. It'll also be harder on the clutch in stop/go traffic because it will take more clamping force in order to get the car moving, which means more friction.
A gear/mph calculator is on this page:

http://www.andysautosport.com/learni...r/calculators/

Phoenix'97

There is varying opinion on the matter of putting more load on your car with a higher gear ratio. The opposing opinion from another forum states that this makes no sense since the transmission is built to handle low RPM driving, it is the motor that is of concern! I can always downshift to a lower gear if it feels like the drive-train is shuttering as the motor is making audible grinding noise! The higher rear axle gear is not the problem, lugging the motor is!

Now, with the concerns for no longer being able to use 6th gear, this is not true so long as I am driving above 65mph! Again, the RPM range I am using on the expressway/interstate is 1500-2000 RPM! Even with a 2.73 gear ratio, I can still use 6th gear and to better effect than driving at 2500-3000 RPM going 65-70mph with my 3.42 gear ratio. See why I want a higher gear ratio?

Now, maybe there is something to my Jasper remanufactured LT1, although I doubt I have an RV-type cam, it could be my shorty headers. However, driving my car at 60mph in 6th gear at 1500 RPM or a little lower is no problem in my car! There is no shuttering, no audible grinding, the car has enough power to cruise at such a low RPM range. So, I am not buying the story being my motor not being able to handle it.

As far as clutch wear, the same can be said for my 3.42 gear ratio! I am constantly on and off it, engaging on inclined roads and disengaging, I am constantly shifting to higher gears and then having to coast to a stop, and in very bad city traffic, I am crawling while riding the clutch on and off. That kind of abuse is the norm for city driving! Gear ratio has no impact on it! The only difference with a 2.73 that I am seeing, I will idle at a faster speed at 1000 RPM than with my 3.42. For city driving and feathering the gas pedal like I do, this is a good thing to be able to do, move faster with little effort from the motor. It sounds contradictory but it is true for my application.