General LSX Automobile Discussion - Modding the LID?

Can the stock air lid be modded (ie. grinding the baffles out of it) to perform like an MTI or SLP lid? I am sorry if this is stupid, I have never SEEN a lid dissassembled before so I dont know what I would be working with, but this sounds like a potential "free" mod??

http://i79.photobucket.com/albums/j123/StrobinAvalanche/PICT0003b.jpg

Hmmmm don't know how much of an improvement it would be.

One free mod to the lid is to trim down those ridges, they are designed to channel the air, but alot of people think they get in the way. Theres alot more info here (http://www.gmhightechperformance.com/tech/0311htp_ls1_fbody_10_free_modifications/), its a very good article, I read it like 20 times when I first found it when my car was stock.

So...whats the point of buying a lid, anyone willing to take a pic of an MTI or something?

They transition into the maf alot smoother

I did that with the old car. I broke all the fins off and sanded them down. Then I got rid of the air baffles around the lid and used a 3 into 4 in tube to place inbetween the lid and maf aka Fernco mod.

So...whats the point of buying a lid, anyone willing to take a pic of an MTI or something?

Two reasons really, 1. Before the air that goes through the stock lid reaches the TB it travels through the baffels on either side, these baffles are connected to the lid by the oval shaped hole on the lid, then connected to the TB by the circle hole in the baffles them selves. The baffles are as wide as the lid and about 4inches back, basically the air circulates inside then goes to the TB. 2. An aftermarket lid is larger, it eliminates the baffles and connects directly to the TB (thats why they have the circular opening opposed to the factor oval) they are also smooth underneath.

Nice! Oh, another thing, I heard a stock 2002 M6 Z28 today. I talked to the owner (Wifey was driving it, she bought it for the husbund, I envy him :( ) But I couldn't help but notice how QUIET!!! it was. What is the cheapest way to make one louder. I have been thinking DMH E-cutout. What do you guys think? I like the E-cutout idea, sick when I want, quiet when needed, and only $200


Also, Subframe connectors. I can buy them for $150 (anyone now of cheaper?) and a shop I know will weld them in for $100. Is this reasonable? The reason I want subs is b/c the whole T-top/unibody thing. Will subs make a difference really or not?

Can the stock air lid be modded (ie. grinding the baffles out of it) to perform like an MTI or SLP lid? I am sorry if this is stupid, I have never SEEN a lid dissassembled before so I dont know what I would be working with, but this sounds like a potential "free" mod??
No point, I suspect an aftermarket lid has more than just better flow, such as increased plenium chamber. This relates to a thing called airbox resonance and is the bases of all good intakes.

Also the outlet hole is different. Biggest thing is you need to remove the large baffles/silences between the lid and the MAF (not shown in the above pic) so you'll end up buying ducting and fabbing it up and it will probably look horrid and not perform any better.

Plus a lid is only $95 - if that's too pricey then you shouldn't be modding :jest: ;)

Cut-Out is the cheapest and easiest way to make it louder. Of course it will get you more power than any catback and sounds pretty good after stock cats. Sounds good for the SFC's. People argue whether they are worth it or not, but cheap insurance is cheap insurance, if you need it, great, if not, well.. it was cheap. The T-top 4th gen F-bodys are just as strong as the Hard-top, if you pull the head liner down on a hardtop you'll see what im talking about. If you go to the track and stick with 4k launches, SFC's are a good idea, if not, well again, cheap insurance.

Cut-Out is the cheapest and easiest way to make it louder. Of course it will get you more power than any catback and sounds pretty good after stock cats. Sounds good for the SFC's. People argue whether they are worth it or not, but cheap insurance is cheap insurance, if you need it, great, if not, well.. it was cheap. The T-top 4th gen F-bodys are just as strong as the Hard-top, if you pull the head liner down on a hardtop you'll see what im talking about. If you go to the track and stick with 4k launches, SFC's are a good idea, if not, well again, cheap insurance.


Car will not be a strip whore, will I notice less rattles and creaks with the SFC's or no? We have a lot of potholes here, will it matter?

Nice! Oh, another thing, I heard a stock 2002 M6 Z28 today. I talked to the owner (Wifey was driving it, she bought it for the husbund, I envy him :( ) But I couldn't help but notice how QUIET!!! it was.
Strange by most new car standards (espcially in UK) I though it was quite vocal, mostly engine I admit.


What is the cheapest way to make one louder. I have been thinking DMH E-cutout. What do you guys think? I like the E-cutout idea, sick when I want, quiet when needed, and only $200
Depends, there are lots of catbacks out there which are fairly cheap and easy to fit. A cutout will need welding in so its extra cost.

Personally I am no fan of a cutout. If you have a good exhaust with mufflers that flow as well or better than the tubing then there is nothing to gain by by-passing them. The only affect you will have is the exhaust pressure wave. And sometimes this will be a negative affect.

So the only use for a cutout is volume control and thats only if the catback is fairly quiet.

Also, the stock tubing is 2.5", so the cutout will need to be 2.5" however you can not by-pass the tubing. 3" is really the minimal you should be looking at with an LS1. 2.5" is too restrictive even in stock form. Also all aftermarket catbacks are 3" so if you ever get one your cutout is useless.


Also, Subframe connectors. I can buy them for $150 (anyone now of cheaper?) and a shop I know will weld them in for $100. Is this reasonable? The reason I want subs is b/c the whole T-top/unibody thing. Will subs make a difference really or not?
I wouldn't worry too much about it being a T-top or unibody, unless you have REALLY sticky tyres and some 500hp to play with you are not going to bend the chassis.

SFC's are still a good idea. The box sections ones are good as you can then use them to jack the car up on, you can't do that with the tubular ones. Personally I like the UMI Performance ones (that's what I have). But they are all pretty similar.

Just a last note.

Ages back I watched a vid. Two cars, one ALL free mods, they had done every thing that was free, plus they had a cutout. Remember free mods are not always free. Against a lid and 4.10 geared car. Both M6's. The car with the lid and gears simply walked away from the other car. Even though their mod list was actually smaller. And in reality they had probably not spent much more money either.

Good setup and well chosen mods vs. Crap setup and waste of money mods.

I just found it to be ungodly quiet, and the cut-out would cost me $200 + welding, the cheapest cat-back I found is a Hooker with the Aerochamber muffler. How are those for power?

Basically, you guys say "no" to the SFC's unless i put stickies on it? I just want to minimize sqeeks/rattles as much as I can.

Is the F-body as rigid as the 05+ GT's? (they are 31% more rigid than the 99-04) How does the F-bod compare in rigidity to the 99-04's?

Car will not be a strip whore, will I notice less rattles and creaks with the SFC's or no? We have a lot of potholes here, will it matter?

SFC's or not, bad roads will lead to rattles and creeks. If it makes you feel any better, my car has 145k on the body and doesn't really make a peep unless its a really bad road. Oklahoma has alot of them too. I usually grease all hinges etc. every 6 months or so.

Does anyone have a link to 4th Gen F-body chassis specs (torsional rigidity, ect) I have a GREAT LS1 engine article, anything similar for Chassis development?

I just found it to be ungodly quiet, and the cut-out would cost me $200 + welding, the cheapest cat-back I found is a Hooker with the Aerochamber muffler. How are those for power?

Basically, you guys say "no" to the SFC's unless i put stickies on it? I just want to minimize sqeeks/rattles as much as I can.

Is the F-body as rigid as the 05+ GT's? (they are 31% more rigid than the 99-04) How does the F-bod compare in rigidity to the 99-04's?
No sorry I think SFC'f are still a benefit, I just wouldn't really worry too much about bending anything like the main structure. It just isn't going to happen unless you have an extreme setup. But SFC and adjustable LCA, PHB will all be nice additions.

As for the s197, well I don't know it's offical nm rotation torque and twist figures. I would say they are probably comparable. Remember the older sn95 was based off an old Fox platform which had been around sine the 70's. The 4th Gen Fbody was new in 1993 and has proven very capable in competition.

Now I'm not saying its the best. But the type of roads I drive on are nothing like US roads. These are tight twsity, often slippy and very bumpy with off camber corners as well. They are a lot of FUN :nod: but it does test a car out well. Now the Fbody is heavy, but I've driven Mercs, BMW's, Jags and other big and small cars on the same roads (probably 40+ different types of car) and I feel very confident to say the Fbody 4th gen platform is actually very good and very capable.

The stock suspension isn't the best and high speed body roll isn't controlled brilliantly, but new shocks and sway bars (Sam Strano @ Strano Performane Parts) will sort it all out. And occasionally you can catch the live rear napping where an IRS would probably have coped.

But overall I am very impressed with the Fbody even in totally stock trim.

This is probably the cheapest exhaust I know of: http://texas-speed.com/shop/item.asp?itemid=195&catid=46

TSP Rumbler, it essentially a Dynomouth (SLP Loudmouth with a Dynomax bullet) but in mild steel. It isn't the best, but it is cheap and free flowing and should dound pretty darn meaty if a tad loud.

Failing that have a look for a 2nd hand exhaust.

IIRC the 05+ GT can take 15,500# torsion before deflection 1/2 degree.

After market lid and free ram air mod is worth the $100. You will notice a nice intake noise when you hit the gas vs stock.
http://img.photobucket.com/albums/v629/blue02formula/6ddf274b.jpg

With boxed subframe connectors, lower control arms, panhard bar, and stut tower brace, my car has less creeks and rattles with 124,000 miles on it than it did when I drove it home new.

After market lid and free ram air mod is worth the $100. You will notice a nice intake noise when you hit the gas vs stock.

With boxed subframe connectors, lower control arms, panhard bar, and stut tower brace, my car has less creeks and rattles with 124,000 miles on it than it did when I drove it home new.


Nice, sounds good. I will go ahead and get the SFC's then. And save the cat-back for later. how much whp is a cat-back worth over stock anyways?

Also, how loud is an LS1 F-body under WOT, I know at idle I can hardly hear the thing, please tell me its louder than a GTO WOT, those things I couldnt even hear from inside hardly.

the idle of an f-body, at least my car, is 550 rpm's. you barely hear anything at all. even with my cutout open it's not loud. f-bodies start making noise over 2500 rpm's like clockwork. at WOT, they're loud. will they be louder than a GTO? depends on the exhaust system. running open headers, the GTO should be louder since it has more cubes, at least i think so.

the GTO I drove was 300 miles on it bone stock and sounded quieter than my old crown vic under WOT.

You're reasoning was just like mine for the cutout. Stock quiet when I want it, then an unleashed beast most of the time. Plus I kinda like the look of the z28 tips. And it's cheaper than the magnaflow i wanted.

You're reasoning was just like mine for the cutout. Stock quiet when I want it, then an unleashed beast most of the time. Plus I kinda like the look of the z28 tips. And it's cheaper than the magnaflow i wanted.


Yeah, thats why I lean towards it, it will make it stupid loud when I want, or stock when need be. Plus I can open it at high rpms and leave it shut at low rpms to not sacrifice low end tq of a race muffler.

GM High Tech Performance had a very interesting article on lids in this month's issue . If you don't have a subscription to that mag , it is the one mag all LSX owners need.