Dynamometer Results & Comparisons - How good is the stock catback pipe?? + $2 worth of washers worth 4 RWHP,with sheets.

I have been preaching this for years and proved it today. If you take the stock catback PIPE and put a straight through single in/single out muffler on it and a turn down under the bumper it flows REALLY well.

The exhaust previous pulls:

Pacesetter long tubes
Pacesetter Y pipe
Stock catback PIPE with a Bullet in the I pipe and a Magnaflow straight through muffler with a 3 inch turndown on the drivers side under the bumper.

The only changes I made were:
SLP 2OTL full catback
Cut the neckdown off the Pacesetter Y pipe.

The SLP 2OTL made 5 FIVE more rwhp than the stock pipe with the straight through muffler setup.

375 vs 380.

Also, I took and shimmed the radiator hold down up 1/8 inch and it was good for 4 rwhp and 3 in tq(hood still shuts) third pull so engine was heat soaked.

Just thought I'd share.

All dyno runs were corrected.

Pics??!

Pics??!

Of????

Pics of the washers or bs.

in for the photos and the exhaust before and after......

Pics of the washers or bs.

Alllllrighty then.

Before
http://i1122.photobucket.com/albums/l528/FASTFATBOY1/Exhaust.jpg







After

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash3/s720x720/563387_10151437222595314_695920313_23489144_677762 620_n.jpg

I am not sure what you are trying to prove with the exhaust. Any highflow muffler will outflow a stock type. No flame at all, just maybe I am am missing something.

FYI, I did the same thing on my 92 B4C.

I am more interested in the radiator. :D

Point I am making on the catback is guys buy $500-600 catbacks to make 5 more rwhp that I did with the stock setup with a good muffler.

As far as the washers go, put 4 washers on the bolts the under the radiator hold down to shim up the lower airbox.

Simple, and no I am not going outside to take it all apart to take pics of that lol.

I was kidding :D

But nice anyway.

I remember many years ago reading where a magazine did the washer shim trick and some other free mods to a ls1 car.

Point I am making on the catback is guys buy $500-600 catbacks to make 5 more rwhp that I did with the stock setup with a good muffler.

As far as the washers go, put 4 washers on the bolts the under the radiator hold down to shim up the lower airbox.

Simple, and no I am not going outside to take it all apart to take pics of that lol.

Ahhh I see what you are saying and yes, been doing this instead of buying the whole catback for 15 years.

Kinda like the new 5thgen guys buying the $400 muffler delete system, that costs about $10 to replicate.

As far as the washers, I don't have a Camaro, so just whenever you get a chance to take a picture, I am interested.

Ahhh I see what you are saying and yes, been doing this instead of buying the whole catback for 15 years.

Kinda like the new 5thgen guys buying the $400 muffler delete system, that costs about $10 to replicate.

As far as the washers, I don't have a Camaro, so just whenever you get a chance to take a picture, I am interested.

The washer trick only works on 98-02 F Body cars.

I get that. I am in the market and researching, so AGAIN, when you get time pop me a few photos.

Thanks!

I get that. I am in the market and researching, so AGAIN, when you get time pop me a few photos.

Thanks!

LOL, if you cant pull four screws out of the radiator hold down, pull it up, put four 1/8" thick washers under it and bolt it back down.

You need to sell all your tools LMAO.

^^^^ low blow :punch:

^^^^ low blow :punch:

Tough love:engarde:

^^^ LMAO Should add the radiator mod to free mods list though. ;)

ha ha ha fat boy, don't get mad because mommy took away the donuts this morning.

Now get out there and take me some fn pictures asshole!

HA Yessss

ha ha ha fat boy, don't get mad because mommy took away the donuts this morning.

Now get out there and take me some fn pictures asshole!

LOL, you figure it out....I did.

Might wanna call someone to hold your hand while you take out the 4 bolts:gtfo:

^^^ LMAO Should add the radiator mod to free mods list though. ;)

They really should, its worth it.....I was surprised even on a heat soaked engine.

Course you will have to get someone to take pictures and make a 4 paragraph instruction post to take out 4 10mm head screws:barf:

Point I am making on the catback is guys buy $500-600 catbacks to make 5 more rwhp that I did with the stock setup with a good muffler.


But that $500+ spent on a catback bought all new piping and new tips made of quality material that's going to last. Versus old, hacked up stock junk with an aftermarket muffler, not really the same thing. I see your point with what you did though, definitely a great alternative if performance is your only goal.

LOL, you figure it out....I did.

Might wanna call someone to hold your hand while you take out the 4 bolts:gtfo:

I don't have hands, so I will just watch.

Of????

I wasnt sure about the exhaust setup..

Pics of the washers or bs.

LOL

But that $500+ spent on a catback bought all new piping and new tips made of quality material that's going to last. Versus old, hacked up stock junk with an aftermarket muffler, not really the same thing. I see your point with what you did though, definitely a great alternative if performance is your only goal.

Quoted for truth..

I remember many years ago reading where a magazine did the washer shim trick and some other free mods to a ls1 car.

I googled that, cant find it.

FFB, you have a lift in your shop...?

FFB, you have a lift in your shop...?

I do, yassir

I do, yassir

Congrats, I swore after crawling my fat ass under my car countless times doing headers and motor mounts this past winter on my car, I would not do it again until I have a lift which of couse means building another shop due to my normal garage ceiling height of our attached 2 car garage. Looks like your shop is a pole barn too? Considering a 30x40 or 40x40...?

My back still hurts...:mad:

Congrats, I swore after crawling my fat ass under my car countless times doing headers and motor mounts this past winter on my car, I would not do it again until I have a lift which of couse means building another shop due to my normal garage ceiling height of our attached 2 car garage. Looks like your shop is a pole barn too? Considering a 30x40 or 40x40...?

My back still hurts...:mad:

Yeh my body is all fucked up, I am WAY too old to do this shit on the ground any more.

My road race car is also a street driver, so every event I go to I swap pads, rotors,wheels, put on brake ducts and every other event do an oil change... its a PITA.

Shop is a 20x30 pole barn, bottom of joist is 9 ft, roof of car goes up between the joist(6 inches past joist). The rack goes all the way up, 74 inches.

Look on GregSmithequipment.com thats where I got my lift. Put it up about 2 weeks ago with a buddy.

Just got done doing the shim mod. Thanks man!

Just got done doing the shim mod. Thanks man!

Please post pics for the 'tards in this thread LOL.

BTW, you MIGHT be able to shim it higher than a 1/8 inch. Put a little grease on the highest part of the lid and lightly shut the hood to see if it touches, go as high as you can.

Dont slam the hood, it will break your lid.

Just got the one pic - stacked two washers to 1/8" high.

http://i21.photobucket.com/albums/b287/6pkman/IMG_0290.jpg

The hood touch your lid? Mine just barely does touch.

Nope clears just fine - though I wouldn't slam it. lol

How does shimming the radiator hold down pick up HP?

because its also your lower air box so it cools faster and stays cooler, because it only has 4 small points of contact.. VS laying right on top of the radiator, holding in all the heat.. cooler air more power

thats my take on it anyway i could be wrong

Ok that makes sense. Thanks for the help.

It opens the gap in the inlet between the box and top core support.

I was curious years ago when my buddy had is 400rwhp cam only 2002 SS on the rollers. I was curious about the power difference between a WS6 lower box and a SS lower box,the WS6 lower box(and only this one) has a bigger(taller) opening under the front.

SO after he made his pulls, I pulled up his lower box and stuck 2 screwdriver handles under the box and did a pull.

Average HP went up like 5hp, bottom end tq went WAY up on the initial hit, like 15 ft lbs and carried it to like 4500rpm then it leveled out with the previous pulls lines.

I was shocked.

I could see where if you put all the big stuff, big lid, big MAF, big TB and a SLP style front facing hood with the WS6 lower box it would be worth some power(not to justify all the cost, but if you got good deals on all of it or it was a max effort car).

This test was the reason I put a LT1 WS6 airbox and WS6 style hood on my LT1 car, it was just as good as the setup I have now.

It opens the gap in the inlet between the box and top core support.

I was curious years ago when my buddy had is 400rwhp cam only 2002 SS on the rollers. I was curious about the power difference between a WS6 lower box and a SS lower box,the WS6 lower box(and only this one) has a bigger(taller) opening under the front.

SO after he made his pulls, I pulled up his lower box and stuck 2 screwdriver handles under the box and did a pull.

Average HP went up like 5hp, bottom end tq went WAY up on the initial hit, like 15 ft lbs and carried it to like 4500rpm then it leveled out with the previous pulls lines.

I was shocked.

I could see where if you put all the big stuff, big lid, big MAF, big TB and a SLP style front facing hood with the WS6 lower box it would be worth some power(not to justify all the cost, but if you got good deals on all of it or it was a max effort car).

This test was the reason I put a LT1 WS6 airbox and WS6 style hood on my LT1 car, it was just as good as the setup I have now.

Not trying to call you out but do you have access to those dyno sheets? I think this mod is interesting and might do this myself.

Not trying to call you out but do you have access to those dyno sheets? I think this mod is interesting and might do this myself.

LMAO, not gonna call me out on $2 worth of washers??????????

Here are my sheets.

Before SLP 2OTL and washers

http://i1122.photobucket.com/albums/l528/FASTFATBOY1/z28tune5and6withtorque.jpg

The 380 run is the SLP 2 OTL, the 384 is the washers.

http://i1122.photobucket.com/albums/l528/FASTFATBOY1/Z28with2OTL.jpg

you should post the dyno info, The STD correction factor ...098 or 1.0 whatever for both pulls the temp/hum. How pulls did you do? I do 3 GOOD pulls with the same time between them 10-15mins, This didnt take you alot of time to change, Like cams, (2-4hours) exhaust, intake stuff Ive done alot of. And drive the car on the dyno to get to same temps before going WOT and recording info.. Then take the closer pull of the 3 to compare to the other setup. Its super hard to see 3-4whp. I'm mostly after hours stuff, so 6-7pm to late night so the air change is a bitch.

I'm suprised you run the "free ramair" cut lower trim still? get a SUX2BU setup and see what it gains on the track. The shim thing I not saying is not a gain, but seal it up so its not getting air from the front and see what it dose at the track. I dont think shipping it up would help. Getting the filter 1/8 up more, if you have good forced air to it.
Ive heard of guys unbolting the plastic and putting a 2x4 block under it spacing it up evern more, or un cliping the lid with no filter, spacing it. And its 5-7whp, but if you do that dyno crap your a dumbass, kidding yourself.

Oh, My 2OTL makes 7 less whp (un modding 3inch inlet). Then unbolting the over the axle tube I made (part of the magnaflow) and running the end of the Y pipe open (4inch) along side of the torque arm before it goes up over the rearend.

Did this mod today, had some extra washers in the tool box. Can't hurt, extremely simple and hopefully gains a few horsepower.

Good call-out Fastfatboy!