what mods are common?

ok guys since things seem to be slow around here im just gonna try to get some stuff started...

1st off i dont even know how long im gonna have the vette... i just keep putting miles on her (like 2500 in a month and a half... and this is my weekend only car!!!), though i know they will slow down as the new wears off im prolly gonna have 50k on her by the end of the year if the trend continues...

im an active memver on ls1.com so im not an idiot about the motors... heads, cam, intake, headers, free flowing exhaust and other lil goodies you can pretty easily see 450 hp at the motor if not to the wheels... but what are some vette specific things... mainly in the trans axle area and suspension/body stiffening i need to know about...

if i keep it im either gonna go for like 450-500 rwhp (i know 500 is virtually non street drivable) naturally aspirated hp or try to do a sneaky supercharger (ill explain later, dont want to give any ideas away and have someone beat me to it)...

right now money is an issue, but ill do small stuff here and there and in prolly 2 to 2.5 years ill start modding pretty heavily unless i see the miles racking up... and then i might just get a new block so the car isnt down while i build the motor... or i see ppl treaing the c5 like a c4 (you know what im talking about... for some reason the c4 is like an ugly stepchild to most ppl)

i have z51 suspension and actually like the ride height my vette is at right now (dont know if its stock or not) i think it has corsa exhaust... i cant find it stamped on it anywhere, but it is stainless and corsa matches the way its built and the tips that are on it.

the first mod i was thinking was either a zo6 airbox lid and a k and n.... or just a k&n and cutting out my stock box... i know there are some nice CIA systems out there, but i really dont want to spend that much cash on some of them (vararam for instance)... oh and add the vents to the foglight area so that i can get some colder air in there... then i was thinking prolly a short thow just to make it a lil funner to drive...

but let me in on some of the secrets that i need to know about a vette.... inform an f body guy about the world of the big brother...

-me

If you have been around ls1.com then you know most of what works, what doesn't: you will learn little additional here, just confimation of what you already know. Things to consider are:
- The stock bottom end can take about 500 HP (if abused or run hard) or 550Hp at the rear wheels (if not), and no more.
- Power costs money
- Without a supercharger. or adding cubes, you basically are playing all the traditional hot rodding tricks -- they all work well on the LS1 and LS6 but the fundamental rules are the same as they have always been. In the LS case, you can "have your cake and eat it too" have more of everything, to the extent of about 10% through various means (long tube headers, CAI, bigger valves. After that, you can get gobs and gobs of additional HP, all at the top end, but moving the torque peak up the RPM range with cams, intake manifolds, etc., but you give up some low end torque and driveability. High end HP is great on the strip, but low end torque is what makes a car great around town.
- As to supercharger tricks, there are a lot of them in use and most work well, with various advantages to all. The Magnusen is the best daily driver, Vortech and Procharger prvide more high end boost, and the turbo kits deliver the most top end of all. The elctric units don't have the flow to work on a 'vette (and won't until they can be run by about 42-56 volts or more).

- Obviously, since I practice what I preach, I advise: buy cubes and superchargers: you get HP and torque with either, and gobs and gobs of both, with both.


Overall advice: map out a long term plan, so you know where you are going in the long run. For example, yu can make a big difference for little money with: 1 3/4 inch long tube headers, CAI, 1.8:1 rockers (and new springs), and a basic (same diameter tube) cat back exhaust. that won't set you back too much and it will make a noticeable difference, one you can feel. Its about as much bang for the buck as you can get for no much money.

But if you THEN decide you want more, like with a good heads and cam kit, you have to throw all that away: the headers are too small a diamter for the flow that will exit the exhaust ports of a really good heads and cam or SC kit, the rockers can't be used with aggressive cams (so you are back to a good aftermarket set of stock ratio ones), your CAI will likely prove to small a diamter to feed a good aftermarket throttle body, and a stock diamter cat back is too small for a high HP engine: so you'd have to replace it.

oh yeah... i completely hear you there... thats the way it is with all projects... and the s/c im looking at is a small compact and quiet unit... i choose to leave the name unsaid because i really want to be the first one or one of the first to pull it off... untill i descide whether im gonna keep it or not im just gonna do cia (maybe just mod my current one) i dont want to get too extreme because it will actually lower the price if i want to sell it... just some stuff to make it fun and keep my friends 99 cobra stay in the rearview...

i was actually just looking to liven up the board and have something to read... what about non engine related stuff... im not big on appearance stuff... the vette is nice as it is... so i was thinking some simple stuff, maybe like aluminum face gauges and aluminum corvette inserts for the passenger dash... thats about all i plan on doing... wheels eventually, but nothing drastic...

i really want a sleeper... i mean i want to be able to pop the hood and say someone say ok so he has done some work... but i got this... or pull up and say hey look a kid who thinks he's a big shot in a vette im gonna smoke his ass... and then whip thier ass...

my goal if i got a t/a was pulling the front tires... dont think that will happen in a vette... soooo i dont know what my goal is now...

-me

You can pull the front tires of a vette: with about 600-650 RW ft lbs of torque or more, suspension mods, 3.73 ratio or higher, and good slicks (and a good launch of course), but it is very hard on the frame/body, but it will put you in the 9s. I don't use slicks on my vette because I don't want to abuse it: love it too much.

Someone posted some pictures in the Video forum here of a couple of 'vette launching that lift the front tires on their way to some high 9 runs.

yeah im not really into slamming a vette down like that... maybe ill go for like burn outs over 100 or something... i need a goal...

-me

Hey predator, my goal as far as HP is concerned is pretty close to yours. I want to eventually be putting down about 500 to the ground. I'm still now sure if I want to just throw a Magnuson on it along with a good head/cam package (and what ever else is needed to make it all work) and call it a day, or I've been thinking about going with a new block (LS2 402ci) and build upon that. I'm thinking the new block maybe the better way to go, just because I know I have a bottom end that can support more HP if I ever decide I need more in the future. So many choices and so little money...what to do

Ultimately, knowing that the bottom end can take whatever you engine dishes out is worth it, frankly just for the peace of mind alone - plus when you add an aftermarket rotating assembly you can buy cubes, too: the additional 56 cubes of a 402 will make a world of difference just by themselves. And it really is not that much money, either, for all that you get.

hey preditor, i just dropped off my car at the motorsport shop to have some mods done.
previously i put on a corsa indy exhaust and a k&n air filter and alot of chrome in the engine. this is my 3rd year owning the car and decided it was time for some real horsepower mods i could afford.
now im putting on aftermarket heads port&polished, rockers,rods, lifters. a stage 2 cam, 1 7/8 kook headers and high flow cats. with these mods i should be around 420 to 440 rwhp close to 500hp at the flywheel. It definatly will not be a sleeper, it will sound like a raped ape.
i was able to start up a couple vettes they had in the shop and was pleased with the outcome. that should be plenty for the thrill. the cost is around $7000.00.
ill let you know in 2 weeks how it turned out.
i was all for the supercharger but wanted to have that nice came sound. maybe ill add it in a couple of years.

see that one of the things im hoping i can do a supercharger and keep the cam lope minimal for more of a sleeper... i just dont see a corvette as like a big lopping fire breathing dragon... more of a refined high class cruiser that has the ability to scare the hell out of you... and i want to stick with that image...

and i really dont want to loose the ls1... im sure ill yank the engine and do full internals, if i dont just build and ls6 for it... and i know that the 402 has more potential in the the long run, but come on when you are laying 500 to the ground you seriously need psychiatic help if you arent scaring the hell out of yourself...

-me

quote:

ORIGINAL: predator

i just dont see a corvette as like a big lopping fire breathing dragon... more of a refined high class cruiser that has the ability to scare the hell out of you... -me

Yeah, it actually is a refined car, at least if you do it right. Before the current 427 with Procharger, I had a stock LS-6 with a magnusen and headers, cam, etc. So, I've done the tour:

A couple of points about SCs. The vortech, Predator, and Paxton all make a sort of tinkling sound at idle that is unmistakable to the trained ear. It is not obvious, but those who are into cars know and recognize: I hae had a suyrprsing number of people say "you got a supercharger in that?" just from pulling up alongside - you can't hide the sound at idle from those who know what to listen for. Theyalso make a reasonable loud wail like a turbine at full throttle and high revs.
The Magusen and other screw types make just a tiny bit of a similar "tinkle," but so little that at idle no one will recognize it. However, at full throttle, you have the hood bulge to give you away with one, and a Magnusen, particularly one with an aggresive pulley, will make MORE noise at full throttle than the aftermarket exhaust. It is an incredible, wailing howl that overcomes all other noise -- it is awesome, but hardly subtle. On the other hand, a screw type delivers low end torque that is just wonderful.

are yall gonna make me give up my secret? dont do it to me... ok ok ill say it since anyone that has a FF and MM mag has read it anyway... look up rotrex.... they are frictiondrive planetary gear style setups... very quiet at idle and they are able to spin way faster than a gear driven unit making them quite small... mount that lil buddy on the botom of the motor... run some tubing up in the stock location... a lil methonol injection to keep an inter cooler out of sight and bam sleeper supercharger.... ok so its not that easy, but thats the fundementals of the plan...

-me

Just looked up Rotrex and I can definitely say that I had never heard of either that company or that type of forced induction system. Seems pretty interesting, but I'm going to have to do some more research on that one before I can give a true fact based opinion. By the way, how soon do you plan to do your install? I've very curious to see how that plays out for you.

i dont know... i would like to do it asap... ive considered doing it on my stock motor so i can try to get a kit together for it, maybe try to put it out on the market in small quatities... right now i got no money and it would prolly cost around $5k to do... soooooo that is really a hiderence... one of my buddies has a 99 cobra and he is thinking about the same thing since there are vitrually no mounting kits out for these things so we might go in together and do it all at the same time...

-me

I have heard of Rotrex SCrs but only, I think, on small light plane applications - they are small and lvery light and syet generate a lot of boost for their size, so they work well in that application when those characters are critical.

I will be interested to see just what happens with one.

I am not dissing the idea (I like it) but want to make a couple of points. Like most complicated devices the engineering for superchargers is a tradeoff among desired characteristics, and although you can get high boost and volume with small chamber size by using very high RPM, that alone will not exactly replicate the performance of a larger unit operating at lower RPM. My favorite example here is the Magnusen (which I once owned and loved on a stock block vette) which is similar in design to, but much smaller than a Weiand 6-71, but runs at about 2-3 times the RPM to generate similar boost levels. However, it generates more heating and has a more exponential boost curve than the Wieand: 6 lbs of Magnusen boost will not perform as well as 6 lbs of 6-71 boost. Of course, here the size makes a big difference on where and how you can fit it.

Where I am going is: the same ought to be true for the Rotrex versus, say, a Vortech, etc: I would expect it to build boost mostly at the high end and with a of heating of the incoming air, so if it were my project I would work hard to fit an intercooler, preferably a big water cooled one if I could, or an air to air one with an added alcohol spray cooling.

yeah there is alot more thought that needs to go into this... but i think it would be cool to do... but like i said $$$ is a problem... im not sure about the heating... and the car market is starting to use them... i think nissan and bmw are working with them... and i understand about the boost being developed at higher rpms... that is a slight issue... hmmmmm something to ponder... like i said all just ideas that i would try if i had infinate cash... and i will prolly try in the future, but right now... it hard to say when it would happen...

is constant boost bad? lets say that you could develope a constant 6 psi... like with an electic unit... is that bad... does the curve need to climb? if not you might be able to use damn whats the name (where one pulley grows and the other shrinks as rpms increase) to give you like a constant rate of boost, or atleast keep the superchager spooled at lower rpms... you kno for example at 1000 rpms its spinning at 20k and at 6500 its only spinning at like 35k (backwrds from the way pulleys are mormally used, but im sure it wills till work)... so you dont over boost, but you have boost down low still...

keep the questions comming yall are bringing up good questions... and being a mechanical engineer i like to try to solve problems...

-me

Yeah, I have really wondered about using an adjustable radius pulley, somehwat like in a cheap CVT to make an adjustable pulley on a SCr. You could run it so it provided lots of boost down low but did not overboost up high, etc.

My Sears riding lawnmower has two such pulleys in its transmission (many small riding lawnmowers do, particularly those made by MTD ) and I took it apart to study the pulleys (I had to anyway because the damn thing never worked from day one -- kept throwing the belts, so I had to take it apart and modify it anyway). One complication with this idea, is that a 'vette sized SC requires between 50 and 100 HP at max RPM and boost, and I think the best of these moving radius pulleys with a normal "V" belt will handle is about 35 HP.

i might be wrong on this, but i think the power required on the rotrex unit is quite a bit lower... so it might come in under the hp load that the cvt can handle... there has to be something wrong with the idea though... other wise someone else wouldhave done it...

hmmm maybe a duble unit kinda like a turbo set up... one geared to pull hard on bottom thats on a clutch and dissengages when boost is too high... another that spools up to the right rpm range for the top end... :shrug: but that pretty much defetes the purpose of the size... i guess you could always gear a single for loow end response and just waste gate the excess on the top end...

-me

The HP required to turn a blower is pretty much the same (within 30%) regardless of SCr type -- they are just big air pumps and while some designs (usually the large chamber, low RPM ones) are more efficient than others, no design will do significantly better than the others. Most Rotrexs I've seen are for smaller (2 liter) cars and probably require no more than 30 HP tops. A Rotrex than can blow something serious into an LS V8 will need to have at least 50 HP (my back of the envelope computation for high efficinecy at just 4 lbs of boost, the minimum that would make any positive difference at all). It might be possible to make the pulley system work to that level but not much more, and they would need to be pretty big pulleys (and belts) -- it might not be light or small.

so we are basically facing the delima of moving volume... without volume we dont have pressure... because our motor gasp for sooo much air... IFF these tings are as compact as they say they are... i would almost be willing to run a dual setup... one mounted low on each side of the motor... (dont know whats down there now might re consider this when i know). surely 2 of these things could handle a v8... damn it i dont know... and maybe they have started branching out with some bigger models... it was in ford builder and they were saying you could easily make a kit for a stang...

without 9 or 10 psi its not even worth it... i dont know... thats y i would do it if i had infininate cash... so i could try it out and see what worked best...

-me

p.s. im getting sleepy and cant think...

ok so im thinking mods for next winter when the car goes int he garage...

CAI... trying to find a cheap ls6 intake... underdriver pulleys... different rockers (advice here)... short throw...

that should be enough to keep me entertained and infront of my buddies cobra till i deside what im doing in the long term... how much you think i need to save up for all this and yall have any other lil things that need to be added to my list? you know if i could get her up 25 or 30 horse from stock... just something to give me a lil jump im cool for now... well untill my buddy strokes his camaro... then i will prolly not be the fastest on the block anymore...

-me

I can't remember if you already have exhaust done or not, but if not a nice set of longtube headers, x-pipe, and an exhaust will give you a nice jump in HP....along with the CAI and LS6 intake.

i dont want to do header because of

a.) cost
b.) pain of instalation
c.) still dont know what i want to do and dont want to have to install headers twice

soooo im just gonna stick to the corsa catback it came with and hope that is enough flow fromt he back to still make a difference..

-me