99TA-LS1

My Friend Said That This Site Was the Place To Go For Information On Trans-Am's So I Have A Question For You Guys.

I Just Bought A 99 TA With Just Under 99k On The Engine
New Transmission With Corvette Servo And Something Else I Can't Remember From A Vette, Trans-Go Shift Kit.
BMR Subframe Connectors
BMR Rear Sway Bar
BMR Front Sway Bar
BMR Strut Tower Support (I Think That's What It's Called)
Pacesetter Headers
3' Exaust Full Pipe With Cherrybombs (Don't Know the Brand)
Crack In The Front Fender
And The Hood Has A Dent In The Front Like If Someone Pushed Too Hard Or Sat On It.
That's All That's Known But People Say The Engine Is So Clean Work May Have Been Done To The Internals.. Since This Is the First Time I Have Owned A Ls1 I Don't Know Much About It.... I Payed 5500 For It I Just Want To Know If I Got A Decent Deal On It... Im About to Start Adding Some Bolt-On's Soon So Any Ideas Would Be Great.

Edit: Forgot About the Fact That My EGR Valve Is Closed And The Intake (Not Manifold) Isn't Stock I Think I Have The Airbox But It's Not SLP It's LS1 Motorsports.... Any input on That Would Be Great Too!

supersick99z

iTrader: (66)

Ditch the cherrybombs! That's a start! What kind of budget you working with?

99TA-LS1

It Makes It Sound Sexy!
I Have About 2.5-3k

09camaro383

iTrader: (2)

I think you got a good Deal!! do you know what heads you have look for the casting number!! how does your cars sounds does it has a rough idle it may have a cam? put it on the dyno!! other then that there's no other ways to find out if any work have been done to the Internals beside opening it!! if you have stock cam and heads with 2-3k will start with good heads, cam, intake and tb!!

99TA-LS1

I'm Pretty Sure It Has Stock Cams... It Doesn't Idle Rough But It Will Miss Occasionally.. I'm Still Trying To Find Out Why.... A Friend Told Me Because The EGR Valve Is Capped It Will Miss But Idk.... (Any Ideas On Why It Would Be Missing Let Me Know)

I Will Have To Check the Headers Tomorrow Since It's Dark Right Now....

Dyno Is Coming Soon But I Estimate It At Around 360-375rwhp

RPM WS6

iTrader: (3)

Welcome to the world of GM high performance V8s. In this world, our engines do not have "cams". They include 1 cam (no plural), 16 valves, and 16 pushrods; just as God intended it.


I disagree with your friend. If the EGR port was properly capped (meaning no vacuum leak) then this should not effect anything about your idle quality.

The "miss" type sound could be the effect of an aftermarket cam profile, or it could be a any number of fuel or ignition components exhibiting an issue. I would do two things, 1) toss a scanner on the car and check a host of parameters; including DTCs (codes), misfires per cylinder, fuel trims, O2 values, and knock retard to start. Those values could indicate the next course of action. If you wanted to go a step further, you could also take some vacuum readings, check fuel pressure, and do a compression test (assuming you own/have access to these tools). 2) do a complete tune up including all filters and fluids, new plugs/wires, and some high quality injector cleaner.

If you still have stock heads and cam, then there is no chance that you'll make those numbers with the mods you've listed on an A4 car.

99TA-LS1

I'm Still Learning About Cars Really This Is A Huge Step Up From Hondas And 4 Cylinders Lol... Real Power

When We Took It To The Shop To Have Them Run The Computer They Said That The 2 Downstream O2 Sensors On The Catalytic Converter Were Missing But I Don't Have A Catalytic Converter. There Are Some Sensors On The Piping But Idk What They Are For I Assume They Are O2 Sensors.

I Have Done A Full Tune Up... All Fluids, Plugs, Wires, I Ran Zmax Through The Engine And Full Coolant Flush. I Also Had My Neighbor Run His Injector Cleaner ( It Looks Kinda Like A I.V. That Goes Into Your Arm) I Can Get A Compression Test Done If You Guys Think I Should. And I'll Have The Fuel Pressure Checked Aswell

As For HP I Know That Stock It Runs 320RWHP OR Around There. And Full Exaust Can Add Up To 30hp (As Far As I Know) So I Guess A Dyno Would Be Something That Needs To Be Done.... Any More Suggestions Are Greatly Appreciated

Ty

RPM WS6

iTrader: (3)

Welcome to the cool side of the car hobby.

Yeah, I'd guess that when your exhaust was built/installed, they just removed the rear O2s. You don't need them, other than for emissions and to monitor the cats (no point once they are deleted). The other sensors are likely the front O2s. These are required as they provide needed input to the PCM for air/fuel adjustments.

When you had the PCM scanned, did they mention any other codes being present besides the rear O2s?

This is a great start. You now know that your basic maintenance is up to date, which is a good place to start.

These are just a couple of other things you can do if you feel there is a misfire issue. If it turns out that you do have an aftermarket cam, then the sound might be totally normal. I would do these tests as a second round of diagnosis, first I'd want to hook up a full range scanner and look at various things before concluding that you actually have a "misfire problem". Do you have access to a detailed OBDII scanner?

Your estimated power gain from the full exhaust is correct, but your estimate on stock power for a '99 A4 car is incorrect. It would be closer to about ~290rwhp. So complete exhaust plus air lid should put you somewhere around ~330rwhp depending on the quality of your tune and integrity of your engine.

99TA-LS1

The Only Other Codes He Got Back Was The Fact that The EGR Valve Was Missing But As You Said It Shouldn't Cause A Problem As Long As it Is Sealed Properly And I'm Pretty Sure It Is. My Neighbor Is A Mod Shop Mechanic So I Think He Might Have One But I Have To Get Back To FL Before I Can Do That... I Took The TA On A Trip To Test It

Is There Any Way To Check The Cam ( I Have No Clue How To) I've Only Been Learning About Cars For About A Year And Most Of that Was On Hondas
I Feel That The Engine Runs Fine... Other Than The Miss And When I'm Idling And The Fans Turn On My Volts Drop To Around 11 or 10 But I Assume That's Normal If Not Then It's The Alternator

PontiacFan

iTrader: (104)

Welcome a'board', ...,

Yer learnin' new things already!
We'll need some good underhood photos to see the engine mods, & good outside pics just for the fun of it, ...


Location?

99TA-LS1

I Have Already Learned Alot

I'm From Florida (No Undercarriage Rust Woot) But I''m In Ohio Atm

Pics Will Be In My Sig Soon And I Will Post Images In A Few

All I Have Is A Cellphone Camera Atm

RPM WS6

iTrader: (3)

There is really no way to get the cam specs without taking stuff apart. However, there are some things you can look at to give you an idea. I'd check the following stuff with a scanner:

- Desired/commaned idle speed (both in neutral and in gear). Should be 650rpm in park/neutral and 550rpm in gear on a stock tuned A4 LS1. If these numbers are higher, then someone must've raised them via a custom tune. And the most likely reason to raise them would be for an aftermarket cam.

- Actual engine speed/rpm (at idle). This should be extremely close to the desired/command idle speed, both in and out of gear. If not, there are several reasons why it could be higher or lower, but lets focus on one for this purpose. See next step:

- TPS voltage and throttle position angle. If these numbers are higher than the stock range, this can explain why your idle speed is higher than commaned. Someone may have turned the set screw to increase idle speed for an aftermarket cam. Stock range for these numbers at idle should be about 0.4 to 0.6 volts on the TPS and 0.0% to 0.4% on the position angle.

- You can also check the size of the hole in the throttle body blade (you'll need to remove the air bellow for this). I beleive the stock hole size is 5/32", so if you can fit a drill bit larger than 5/32" into that hole, then suspect that it's been enlarged. The most common reason for this would again be to help an aftermarket cam idle (of course, there is always the chance that your TB may have been swapped with a drilled one at some point, or that your engine once had an aftermarket cam but was returned to stock - so don't put too much faith in this one particular test).

- Vacuum readings. You can test this, but the problem with this obviously is that if you have a vacuum leak or a poor A/F ratio at idle (either of these may also be causing the misfire), you may get lower than normal readings - just as if you had an aftermarket cam. So again, I would just use this as another small piece to the puzzle depending on the results of the other tests. One thing to remember is, an aftermarket cammed engine will usually show some needle shake on a sensitive vacuum gage - problem is, not all vacuum gages are super sensitive.

- Have someone that really knows these engines listen to the idle. A stock and properly running LS1 should have a very smooth idle note out the exhaust, but you will feel a tiny bit of shake inside the car when sitting at idle - that is normal.

- Dyno test. You want to do this anyway, so might as well. If horsepower continues to rise as you hit 6,000rpm, then you don't have a stock cam.

That's definitely lower than normal, unless you have a lot of other accessories on (like the rear defogger and/or A/C, etc.). Sounds like you might need an alternator, especially if yours is stock with 100k miles on it.

RTRx7

Welcome.

I'd say you got a decent deal.

It depends on the area as to how good of a deal you got.

99TA-LS1

The Idle Is About The Same As Mentioned When In Gear At A Red Light It Idles At About 500-550 And In Park Around 600 So I Guess That's Inline. A Good Friend Of Mine Owns A 99 Camaro Z28 And He Knows Alot About These Engines So I Let Him Drive It After The Tune Up... He Said It Runs Smooth. But He Is No Mechanic. The Dyno Will Probably Be The Next Thing That Will Be Done. It Will Drop To Low Volts Even If All Accessories Are Off And I Just Got A New Battery. I Just Looked At the Alternator And It's Rusted Along With The Underdrive Pulleys. (Does that Effect Performace I Assume It Does) I'm Going To Get A Good Computer Diag Hooked Up To It And I'm Also Going To Check The TBB Size Luckily I Have A Drill Set With Me.... xD

Here Are Some Pics They Are Off Of A Phone Camera So Kinda Small =/

PontiacFan

iTrader: (104)

EGR has definitely been removed. I can't tell from the small photos if the AIR is gone also, tho I imagine it probably should be. If the previous owner went to the trouble to remove EGR, then most likely he did the !AIR also.

Was the car purchased in Ohio, or Florida?
Lot of rust on the lower compeonts could be a sign of flood history, but I doubt it. Could also simply mean they drove it no matter what the weather was!
But if the alternator is extremely rusty, & many years/miles old, it may be the cause of the gauge drop. Good way to tell would be with a seperate meter to see it in real-time firsthand, ..., rather than relying on an OE gauge.

I think we can all sit back & read the RPM-WS6 replies as he's pretty much given ya lots of good info already!

Arctic2002ss

Sounds and looks like you have the typical performance bolt-ons (headers, lid, and LS6 intake). If they are still stock, I would change shocks to compliment all that suspension work. I would agreed with the 330rwhp estimate someone already made, since it's A4.

99TA-LS1

It Was Purchased In Florida... Kinda Why I'm Leaning Toward Replacing the Pulleys They Shouldn't Have Rusted.. It's Not Extremely Rusty But Too Much For My Taste I I Saved RPM's Last Post So when I Get Everything Tested I Have That Info Available (As Long As RPM Doesn't Mind)

I Still Have Alot To Learn Though... This Is Just the Start

99TA-LS1

Well I Heard LS6 Intake Included The Manifold Aswell.. And As Far As I Know I Don't Have That... Just The Lid.. But You Guys Know More than I Do. As For Shocks That Is Getting Done Asap Pep Boys Has Free Installation On Any Strut Or Shock Purchase (Makes My Job Easier) lol

RPM WS6

iTrader: (3)

I agree, use some other method to verify the stock gage, like a volt meter or a scanner that will show ignition voltage. The stock gages aren't 100% accurate. This also goes for the tach, double check your idle speed with a scanner.

That doesn't look like an LS6 intake to me. I'd say it's an LS1 intake that's had the EGR port capped off.

No problem, glad to help. That's what we're all here for, to learn and help others.

On your voltage issue, yes the aftermarket pullies can also be effecting your voltage. But I'd double check the alternator output and see what it's really at.

99TA-LS1

That's What I Thought About The Intake.... The Pulleys Are All Stock And Rusty So I Want to Get Some Aftermarket Ones. Should I Just Take The Alternator To Autozone Or Discount Auto To Get The Alternator Tested? I Don't Have The Tools At My Disposal