Improving the LS7 -- How?
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Joined: Jan 2002
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From: Nottingham, Notts, England, UK
Originally Posted by Blue Hawk
Reason they went with cast pistons is probably to maintain an acceptable noise level coming from the engine. Forged pistons are noisier than cast pistons, especially when cold.
Boosted.
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From: Itasca, IL
Originally Posted by Spenser309
well thank god the used cheap pistons id be easier to justify changing them to 9 to 1
and mounting up a pair of twin T-60's
and mounting up a pair of twin T-60's
I was questioning why they decided to go with cast pistons myself today...but came to the same thought you did. If someone wanted to make some real crazy power with a turbo or supercharger they would just swap in the dished forged pistons and ditch the cast. If the thing came with forged pistons at 11 to 1 compression ratio I would have a hard time ripping the motor apart to put in a low compression piston for boost and would probably just do a nitrous set up. But then again by the time I can afford one of these there will probably be an ls8, so it doesnt matter much for me lol.
leno's toronado with a preproduction LS7 made somewhere around 1000 on race gas with a TT setup. what are the cam specs in the Phase III berger cars? they make 600 at the flywheel so that is a 100hp improvement and still very drievable
Originally Posted by 52172
Need to install larger valves and a stage three port job? valves are small for a 427 only 2.02 and 1.6 the same on my 346.
LS 7 heads have no flow problems..they are the pretty much the same as the C5R heads...12 degree valve angle!!!
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From: Reno, NV
Originally Posted by DanO
Untill it reaches formula 1 spec there will always be room to improve engine design.
If you could talk to the engineers who designed it they could tell you what comprimises they had to make for $$ and that would be your area of focus for improvements.
If you could talk to the engineers who designed it they could tell you what comprimises they had to make for $$ and that would be your area of focus for improvements.
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From: Reno, NV
Originally Posted by The Dragon
While we're bench racing . . . I don't know . . . if it's starting with ~440rwhp and gets bumped to ~600 rwhp . . . 220 mph is doable with the cd mentioned . . .
Everyone's gotta remember that, if the gearing is the same, this engine will reach it's peak and have a pretty flat power curve riiiiight about where these extreme speeds will be in 5th gear
Everyone's gotta remember that, if the gearing is the same, this engine will reach it's peak and have a pretty flat power curve riiiiight about where these extreme speeds will be in 5th gear
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From: Reno, NV
Originally Posted by Blue Hawk
Reason they went with cast pistons is probably to maintain an acceptable noise level coming from the engine. Forged pistons are noisier than cast pistons, especially when cold.
I am a little concerned and wondering about the weight of a forged piston and acceleration (G) forces. Is it possible a forged piston transmits more Gs to the con-rod and crank? Perhaps those components would be over-stressed with forged pistons?
Some nice LS7 pictures on page 21-23, 28, 29.
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Joined: Jan 2002
Posts: 320
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From: Nottingham, Notts, England, UK
Originally Posted by Builder
Luckily, I won't care about the noise too much, if any. It's all sweet music to me!!!
I am a little concerned and wondering about the weight of a forged piston and acceleration (G) forces. Is it possible a forged piston transmits more Gs to the con-rod and crank? Perhaps those components would be over-stressed with forged pistons?
Some nice LS7 pictures on page 21-23, 28, 29.
I am a little concerned and wondering about the weight of a forged piston and acceleration (G) forces. Is it possible a forged piston transmits more Gs to the con-rod and crank? Perhaps those components would be over-stressed with forged pistons?
Some nice LS7 pictures on page 21-23, 28, 29.
Hi Scott, You can get forgings which weigh less then the GM castings. I think GM have penny pinched where they can as seems to be the trend. Take the rods, under $800 for forged items, thats just to cheap and some steels are lighter. How are they making those in titanium for that price?
Billets cost $4k, sure they're billets but the price difference is huge! Makes me wonder just how much titanium is in the GM rods. I love the ls7 but have some doubts about it if ever it had to do a seasons hard racing in stock form.
How are things progressing
Mike.
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From: South Jersey (15 miles from Atlantic City)
Here are a couple ways to improve it right here! This car is sick!
http://www.spdkilz.org/Video-Audio/C...e/C6Z06NOS.wmv
http://www.spdkilz.org/Video-Audio/C...camheaders.wmv
http://www.spdkilz.org/Video-Audio/C...e/C6Z06NOS.wmv
http://www.spdkilz.org/Video-Audio/C...camheaders.wmv
The LS7 heads, while nice, have definite room for improvement. Same with the manifold, its a cheap piece. There are some ridges that need smoothed, and the injectors bosses are not uniform and some needed work. My bud has done some work on my heads, and they are flowing ~390 @ .670 lift (360ish stock), about 330 at .500. Exhaust is about 250 (220ish stock), reverse flowed with a header on.
Teching In
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Originally Posted by Patrick G
I don't know...I think it's going to take more than an extra 100-150 hp to raise the Z06's top speed from 200 to 220 mph. That's moving a lot of air.
Originally Posted by Automobili Forza SpA
A 3000 lb. car can easily go 220 utilizing a 600 horsepower powetrain provided that the gear ratios are as specified above. With proper aerodynamics and a few hundred lbs. of shed weight it could break 240. It's quite possible that you could achieve these aerodynamic requirements with an undertray and a diffuser. That's the thing about air, it moves when you push it>>>
Taking off the mirrors, winshield wipers, and taping up everything would be more benifical than losing weight. weight affects acceleration, and is very minimal when it comes to speed. look at the Bugatti Veryon, that thing weights like 4200(if not more), yet goes 250.
I remember a few years ago Lingenfelter built some bad *** LT1 motors for the F-body salt flat guys in an article in Hot Rod. They added over 1500lbs in ballast (50 gallon water reservoir for the radiator fluid) and tons of lead strategically placed. The car actually flipped over onto its roof at north of 160mph.
Aerodynamics are the key to top end mph and stability... weight is only affecting accelleration for the most part. Air under the car is just as important as going over the car. That is why real supercars have flat bottoms and some even with air channels/diffusers.
Aerodynamics are the key to top end mph and stability... weight is only affecting accelleration for the most part. Air under the car is just as important as going over the car. That is why real supercars have flat bottoms and some even with air channels/diffusers.
Originally Posted by Automobili Forza SpA
A 3000 lb. car can easily go 220 utilizing a 600 horsepower powetrain provided that the gear ratios are as specified above.
As already mentioned, aerodynamics and the way a car moves the air around it at speed is critical when one considers top speed velocities such as those mentioned in this thread. Power and gear ratios are not a large part of the equation.
Ever look under a Porsche?? Or a number of the other exotics?
One cannot make a blanket statement such as the one you did.