F-Body Europe

Guys tell me blocking or disabling my air injection and EGR will pick you up. Is this another lie the guys that dont know much about cars put out, Like taking out a cat will give you power gains lol thats a good one, 75% of people beleive that still even though its been proven to be false.

Took the cats off a stock ZO6 . Gave it a 15 hp increase. Added Headers gave it 20 more . Seemed to worked for this application

im not saying your incorrect but carcraft did a good article, they removed cats and tryed a set of random techs on a TPI 350 and the thing lost a small chunk of low end torque and saw No gains at all also
in an unrelated subject I was at the track today racing at super tens (10,000 to win a day) sadly went out 3rd round but the photographer took some damn cool pics of my car, unfortunately it take 4-6 weeks to get them but these pics are worth the wait, ill post em when I get em, one is a massive burnout which is my usuall lol and my car leaving on the lean with it all torqued up and the drivers side front wheel ALMOST off the ground, really cool pics, I had no clue my car looked so cool lol.

maybe I am missing something here in the message.....

dude, simply removing cats won't do much by themselves

removing the cats reduces back pressure which contributes to better flow

AT HIGH RPMS. for a freer breathing motor, WITH proper INTAKE RELATED MODS IN PLACE.

dude, the power gains will slap you in the face, if the proper mods are applied.


you don't see race only cars with cats on them don't you.

I have a 93 LT1 and I HAVE NO CATS. my motor breathes freely and is not restricted in intake or exhaust.

for slow driving AT LOW RPMS the cats contribute to low rpm torque due to the slight restriction of the cats but does not contribute to high rpms

dude as far as simply blocking/disabling your air injection and EGR

by themselves, that don't sound right. with a moderateley or heavily modified machine there may be valid reasons for that

p.s. you won't be street legal stateside- as far as I know without cats

what in the world is stateside............

Disabling AIR and EGR won't help much, if any. Interestingly, the EGR actually LOWERS combustion temperatures at part throttle. This occurs because the exhaust gas that is routed back into the engine is not very combustible at all, less combustible material=lower combustion temperatures.

With that said, I have disabled my AIR and EGR and have had no problems, but I also have not noticed any increase in power whatsoever.

I don't really know about no cats, but when I did my headers I put a straight pipe in place of it, and the car really woke up!!!

John

ohh cool I just got my car 13.522 @ 101 how fast will it go with headers?....Im also gonna program it tommorrow

I hate to speculate, but I'm sure you'll be impressed!!! Maybe 13.2@104???? With good programming it may pick up more than that!!!!!

Dude, rip the damn cats out if you can get away with it. I know for sure it made a big difference I could feel. Dont believe everything you read.

Cats are the devil!

power you can "feel" doesn't exist unless you are gaining like 35 horses or so.....Ripping the cats out will increase your horsepower but only at very high RPMs when the exhaust is flowing alot of waste and they become restrictive...otherwise you loosing valuable low end torque do to lack of backpressure....When I go for the cam i will run long hearders with cutouts after the collectors...With the stock cam I dont beleive loosing the cat is a good idea....If I had bigger gears in the back and my motor was acheiving a higher RPM I would then consisder it....but as long as shes crossing the line at 4700 rpm I need the extra backpressure to keep my car pulling...

Well I dont believe I gained 35 HP but I did definatley feel a difference... Low end torque? The HP difference will more than make up for it. Run your car at the track with the cats on then with them off you will gain MPH and a tenth or two. I have seen it many of times first hand.

Jeff

Okay lets go ahead and get some truths in here . This is just in a nutshell .

Truth number 1.
You do not need backpresure to build torque or Hp. If you do then your tune is out of whack.

Truth number 2.
remove the cats, add headers and you may run lean . This is due to less exhaust pressure. Which in turn will cause higher combustion temperatures. This in turn will cause a certain amount of ignition retard. Which equals less HP. Get your tune right and you will make more hp.

I reprogrammed my pcm for the first time tonight....

I used to hit the rev limiter before the car shifts... so I raised the rev limiter to 6,200 RPMs

I changed the 1 - 2 shift so it shifts 2 mph sooner,
I changed the 2 - 3 shift so it waits another mph to get a better head start at 3rd

I shut off the lockup in 3rd gear @ 95 mph so that the car torque converter will still slip a bit letting the engine rev more...and which should help it get into the powerband more before it crosses the line..

I advanced the low RPM timing 2 degrees at all load ranged from about 1000 RPM too 2500 where I added 1 degree advance to all points from there on

and in the power enrichment table I took away a bit of fuel where the curve sharply get very rich....

any expectations?

Ill post the timeslips and some pics of my car in action tommorrow

WHat are you tuning you PCM wiht> Tunercat? LT1 edit? Is it simple? Did you mess with the air/fuel tables?

Jeff

yes I used LT1 edit
It is very simple to use
if you look at my reply above I say what I had done and yes I modified the power enrichment and ignition tables.....

I took it to Navasoty Raceway (now I know why they call it nasty raceway) and it was horrible! The thing wouldnt hook for "He said POOP"....my 60's were all at least .06 slow and the was a monster headwind in addition to being hot outside...I slowed down .15 and 1 mph over my best time at houston...... I think I actually picked up though considering the conditions..
I was offered a set of stick gears for my camaro (3.42)s recently very cheap so I think I will give those a go...I will post some pics of my baby in action tommorrow

Made 4 new tunes......going to race at good old Houston Raceway Park's test and tune friday night....

Should be no traction problems this time around and also some Cool Crisp Night Weather to make awsome power....

The 1st new tune:

3 more Degrees Advanced timing from 800 - 2000 RPMs under WOT
2 more Degrees Advance from 2000 - 4000 under WOT
Timing tapers into stock after 4k RPM

Power Enrichment has been scaled back 10%

The Knock Retard has been Disabled

The Trans Shift Pressure at WOT has been upped 10 PSI

The 1 - 2 shift is 1 mph earlier and 2 - 3 is 1 mph later

The TCC no longer locks up in 3rd so that It will slip and give some torque multiplication and more MPH

Rev Limiter is set to 6,350

Fans turn on at 190 and 205
........

I also have a same version of the tune except in speed density mode.......

........

There is a third version where the MAF has been rescaled to compensate for porting...and fuel has been further leaned to compensate for that

....... and a speed density version for that as well


I will also try one more tune with 4 more degrees than stock timing down low ......


I will post results for as many of these as I run and if any are good I will make availeble to general public for free.


I will also be installing a B&M shift kit to further stiffen and quicken the shifts....even though it chirps em in the 1 - 2 now I want it to be able to shift hard enough to smoke em

To say the least .......very satisfying

Previous Best run.....13.522 @ 101mph (density Altitude -1400 feet)

I used the first program I wrote but kept adding more and more and more low end timing and it kept getting faster and faster ! I picked up probably .25 with the program I wrote and .10 by taking off the belt which I did last 2 passes...

Results are below


....BEST ET PASS....
R/T ........... .527
60' ......... 1.963 (spinning bad)
330' .......... 5.506
1/8th ....... 8.442
1/8th mph ....... 83.40mph
1000' .......... 11.009
1/4 mile ................... 13.17 @ 103.99

.....BEST MPH PASS......
R/T ......... .495
60' ........... 1.969 (spinning bad)
330' ......... 5.530
1/8th ....... 8.465
MPH .......... 83.37
1000' ....... 11.024
1/4 mile ................ 13.18 @ 104.28

thats .35 faster with my own programming and removing Serp. Belt ALONE!!!


Before I was leaving I was still throwing more and more timing 1 - 2 degrees at a time between 800 - 2000 RPM and it kept loving it!
I can probably get another .05 - .1 out of this program with more work....
Eat that TPIS (said proggy worth .2 )
If anyone would like my .lt1 file you can email me at mandcmain@earthlink.net
This car is completely stock besides my home made exhaust cut out.... and my programming...

I didnt receive my shift kit yet so if I race next friday night expect sub 13 or almost 12 second passes....

Sounds like your on to something there. Keep it up.