dapsaute

Hello all-
I have a low mileage (47K) 1995 Z28 4L60E/3.23 car. I just got the car and am working on starting to mod it. I wasn't expecting to drop $450 on repairing the AC, so that's taken some of my "catback" funds.

At what point would the stock necked down intermediate pipe (where it necks to go into the muffler) become a HP restriction?

I don't have an exhaust pipe expander handy, but are there real...not "go to a muffler shop" options to replace the muffler and tail pipes in my garage?

Years ago I would have just grabbed a Dymomax muffler and pipes and gone with that, but I see they offer very little for the LT1 cars these days.

My main concern is getting a decent set of tail pipes. Mine are good enough to reuse, but I believe they are a mere 2.25" ID.

Any thoughts?

Thanks!
Dave
Utterly Unrepentant LT1 Owner

KyleW707

try texas-speed.com or ws6store.com. They may have some bolt on kits, and if not, you can always just cut your exhaust and use vband clamps with the new exhaust instead of taking it somewhere to get welded

MasterTomos

iTrader: (15)

don't skimp out on exhaust or youll be doing it again later down the road.

Save up some bones for some longtubes from tsp or pacesetter, a y-pipe, and a gmmg catback and you'll never have to touch the exhaust again

dapsaute

Tanks for the advice...with my budget and power goals, my plan was to start with the usual CAI and a Magnaflow #15620.

If I have to get by with just a K&N AF only and the Magnaflow, I'll probably do that.

The GMMG style exhaust sounds really nice...looked at it years ago for another car, but choked on the asking price.

Even though pre-OBD2 cars no longer get tested here in the People's Republic of Illinois, I want to retain as much of the OE Emissions as possible.

The longer term plan is for a set of ceramic coated emissions compliant shorties, Magnaflow y-pipe (single cat car), and the aforementioned exhaust.

From there I plan to move on to the suspension, before doing a 12 bolt and mild 383 or 396 5-10 years out.

With two girls in school, money comes in small quantities for at least the next 5-7 years.

If there are LTH's that can be non-Kalifornia compliant and will fit without a lift and/or tubular K-member, I'm interested.

The car will get driven 2000-3000 miles a year and carry the family out and about...something as loud as a NASCAR Cup car just won't fly here.

Thanks
-Dave

devildog214

magnaflow seems to tick all the boxes, its only about 300-400 new, stainless steel and has a great sound and isn't as loud as an slp or my TSP rumbler.

jrwilliams95z28

x2 magnaflow catback, pacesetter longtubes + ORY. sounds awesome, runs great!

jewbacca

iTrader: (5)

While Magnaflow is a great system, they're not $300-400 anymore. Shame that they jacked up their prices so much in the last couple years.

cardo0

No budget answer. Save your $$$ for a custom 4" or 3.5" exhaust with high flow cat. Closer to $1000 but it will get u where u need to be for any engine upgrades and still be smog legal. My first 4" system from mufflex cost $700 but once i found a good/real exh shop they can match that with the new cat installed.

Be patient and save your money. U have a nice car - enjoy it as is until your ready to do it right,
cardo

jewbacca

iTrader: (5)

No reason he needs anything bigger than a 3 inch I pipe unless he's putting some serious power down. Going to big on the exhaust can lose you a bit of power (read scavenging).

jewbacca

iTrader: (5)

If you want a good budget system that will pick up as many ponies as any other system out there, look into the Hooker Aero Chamber cat back.

cardo0

Sorry but scavanging is developed by tube length and matching tubes to the firing order. And with the limited choice of smog legal headers (all shorties) there ain't much can be done for that.

Restriction and backpressure is what we are fighting with a single pipe, single cat exh. A 3" maybe better than a 2.25 (only = 3.97sq" flow area) but a 4" reduces restriction a whole lot more. If u have only modest plans then 3" (= 7.065sq" flow area) is fine but if look to the future for big power 4" (= 12.56sq" flow area) will get the job done.
I don't even want to hear the "too little backpressure myth" unless u have some real data to back it up - no hearsay BS please. Even with 4" u will have plenty of packpressure. I have never seen a super stocker or pro stocker at the drags with anyting but open header.

cardo

Tom94TA

To save some $$ you could get a Flowmaster 80(?) series muffler and have it welded in place of the stocker, they sound great but people say the ones for our car is restrictive. I have this setup and have a cutout for track use.
For headers try to find some used single cat SLP mid lengths they come up in the classifieds or c-list once in a while. Mac mid lengths are good too.

VAformula

iTrader: (8)

This is how my car was when I bought it, I loved the sound for a nearly stock system, this a good "sound good for really cheap" option and would let you do more up front right now. Its up to you.

jewbacca

iTrader: (5)

Yeah, the "you need back pressure" myth is just that, a bull **** myth. For his setp a 3" i-pipe is plenty. Unless he's going for a max effort (500rwhp) run then I don't see a reason to spend the money on a custom 4" system. The Hooker Aero Chamber will make plenty of power for what ever he''d want to do. Later on if the OP wants to put down some serious power I'd look into a true dual setup.

leadfoot4

iTrader: (1)

Assuming that headers aren't in the budget yet, I wouldn't worry about the back of the exhaust system yet. Pull off your stock exhaust manifolds and look at the carbon outline on their face, where they meet the exhaust ports of the cylinder head.

You'll be SHOCKED at how much that face intrudes into the flow path. Start by "gasket matching" the manifolds with a die grinder or Dremel tool. You'll free up a lot more flow there, and then you can worry about the flow downstream....

smooveZ

Get some Kooks stainless LTs. They are expensive but worth it and a Magnaflow catback.

TAEnvy

iTrader: (2)

You can find used catbacks cheap. I wanted an slp 2otl but since I can't find one I'm gonna make my own using the slp rear pipes and a dynomax vt muffler. The one with the flap in the muffler.

93M6Formula

Since you're on a budget, Pacesetter emmisions LT's, y-pipe, and a hooker catback fit your bill perfectly. You don't need anything more than that for your setup.

duh

iTrader: (16)

Take it from an OBD1 car owner. Go with the non emissions headers here in IL. Since you no longer have to even drive to the sniffer, its easier and will save headaches in the long run. I've got pacesetters and a single exit flow master cat back on my car. Sounds great, and actually gets plenty of compliments. It's not too loud by any means with a stock engine. Then if you so choose to upgrade down the road you can, but it won't be needed until you get into a significantly higher output engine. FWIW the single exit flow master is no longer made for our cars, but you can find them now and again and the are far less restrictive than the 80 series that was mentioned.

dapsaute

Thanks to all for the advice. Because the car will sit winters out here in Illinois, I would be a little more inclined to go with a SS system. If I can't swing the Magnaflow #15620, I'll probably put the Hooker system on, though.

The car is a long term project and will probably end up a lot tamer than the badass tuff I see you guys have.

My goal is to be able to outperform a mildly modded 2011+ "New 5.0" Mustang GT in most respects without sacrificing driveability, streetability, and do it on a reasonable budget a few pieces at a time.

Being able to shut up the LS1 owns at the gym would be a bonus, LOL

The Wife put up with my 65 LeMans for 15 years despite the lack of creature comforts. Adding loud/nasty anything just won't fly.

I also intend to do all of this while retaining the emissions gear even though OBD-1 testing has ended here in Illinois.

The first step is a new exhaust system....as it so happens the OE is pretty rusty from sitting, and a CAI.

Next spring I hope to work on upgrading the suspension, do a front LS1 brake upgrade, wheels (C5 Z06) and tires. If the $$$ Gods smile on me for a change, it will get a Harwood cowl hood and 96-97 SS rear spoiler.

Hopefully then I can move on to a 12 bolt or S60, cam, ported heads, and maybe 4-5 years from now, a relatively mild NA 383 or 396.

Thanks!
Dave