flintwrench69

iTrader: (11)

Even if it was one of the other motors it wouldnt be that dogshit slow.

murphinator

iTrader: (2)

even a 4.8 on dr's should run low 14's and 60 foot better than 2.3

have your buddy with hp tuners scan the car for you - it doesnt take any credits to scan or to clear codes only if you are using the "editor" portion to change tune parameters do you need to license the file.

If the cats are clogged it should have KR like crazy when you get on it.

If its bad coils , plugs ,wires ( ignition) it should be showing a lot of misfires if he logs misfires.

if its a fuel delivery issue the 02 voltages should be reading real lean even when its in open loop - 15 seconds would be damned fuel starved if its a fueling issue.

If the cats are clogged the manifolds should be glowing red after a pass if you lift the hood - but you shouldnt be getting on it with a major issue unsolved unless its once just to see if the cats are glowing and I would make it brief...

our speculation/educated guesses could be way off too - we dont have the car you do , have your friend save your scan and e mail it to you and maybe you could e mail it to a couple of us to review for you - I havent poked around in the tuning section on here to see if you can post an hpt scan or not but if you can that would be a good idea too

or you can try asking for help in your regional forum , I am sure there are some knowledgeable members in your area-this is a pretty popular platform so try posting a link to this thread in the midwestern section maybe???

Lee12609

iTrader: (3)

wayyyy down on power, my stock 98 a4 car traps 82-84mph in the 1/8th stock (at sea level).

youngbird

so I was at work today and I talked to some techs there to to get an idea of what's going on and what you guys are telling me is exactly what going on with the car but I haven't looked at the cats to see if they were overheating but my guess is they have to be I don't want to take it to the track until I install the exhuast with my buddy with HP tuners and read the o2s I think I'm gonna isntall a wide band to I just think its throwing my whole car off but I just don't think theses computers are that smart were it picks that up so I just think its not breathing correcty could be wrong tho but we will see and I will definitly send the data to who ever wants to see it


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RPM WS6

iTrader: (3)

My guess is that they don't *have* to be at all.

Many things can cause this kind of power loss.

If the cats were clogged bad enough to cause significant power loss, I think you'd be seeing other drivability issues as well. Hesitation during acceleration, bucking/jerking during acceleration, poor idle quality, engine unable to attain higher rpms, etc.

I would not jump to any conclusion based on what is known so far. Tossing on new exhaust might not do anything at all. This car needs to be gone over by a person that knows what they are doing with a scanner, IMO.

If you are getting codes for the front O2s, I would start by addressing that. Also, have you looked at things like fuel pressure (idle and under load)? Someone else mentioned cleaning the MAF, I would recommend that as well.

flintwrench69

iTrader: (11)

Youre not going to be able to tell anything by looking at the cats unless theyre off the car & see the catalyst broken inside. You could tap on them & if they rattle theyre probably broken & causing an exhaust restriction. Best thing is have someone that knows how to diagnose cars, driveability tech drive & scan the car. Removes a lot of guesswork & money wasted on throwing unecessary parts at the car.

youngbird

well before i even knew of this problem i already ordered my exhuast so its really not wasting money the car is not missing or slipping the car seems to be fine and i already cleaned maf pretty much eliminated some things already the next thing to do is the exhaust and wait and see it should be here this weekend im 19 years old and im an apprentice tech i know i really dont know alot right now but thats why i asked for some help becuase this is my car and im sure you techs know where im coming from i appreciate all off the great knwoledge you guys have told me i understand most of it and it has helped i will get this car running right or a least find out whats wrong with it

thunderstruck507

iTrader: (18)

Actually they can. If the car has high positive fuel trims the pcm will eventually add fuel to the WOT fueling as a safeguard from running "lean".

I have seen a car go from running mid 7s in the 1/8th to running nearly mid 8s due to a faulty set of front o2 sensors.


Fix the sensors, ditch the cats, and do a tune up and go from there.

RPM WS6

iTrader: (3)

I think you may be too focused on the cats without having tested/fixed other things first. Have you checked fuel pressure? At idle and under load? IMO, that would be the next thing to do. Based on how well you say the car runs and drives when not at WOT, and the fact it's able to attain high rpms, I think a serious exhaust restriction, though possibile, is less likely than the other issues (fuel pressure, front O2s, etc.).

Also, I think the front O2s are a bigger concern than you might realize. This is why:

If LTFTs are positive before going WOT, they will lock at that reading and stay there. So WOT fueling can most definitely be affected by O2 readings.

You mentioned that you are a tech; as such, your first mission should always be to diagnose before just changing parts. Looking at things like fuel trims and fuel pressure, and fixing the bad front O2s, should be done before tossing on new exhaust. When trying to fix a problem, you want as few variables as possibile.

FiredUpZ28

NC98Z

iTrader: (1)

R U sure that the TB is opening up all the way at WOT?

FiredUpZ28

^ Good idea but F bodys are all cable throttles I imagine he'd feel the pedal not going to the floor. At least not enough to cause a 90 mph trap speed....

flintwrench69

iTrader: (11)

Something that comes to mind, when I first bought my SS I had a rotted vacuum line at the pcv valve causing it to set O2 codes & lean codes.

thunderstruck507

iTrader: (18)

Cables can also stretch. The pedal might be bottoming out before the cable is pulled far enough to fully open the blade.

It's worth checking since it takes all of 5 minutes to pull the intake tube and have a buddy look while he presses the pedal to the floor.

usnfenix

iTrader: (11)

this doesnt really seem to be the best way to go at this. me and of most everyone here are thinking the same. i dont think just throwing on a new exhaust will fix the problem. if you have a problem instead of just throwing parts to "see what happens" you should be diagnosing and only buying parts when youve found the problem or at least 90% sure you have. engine codes just dont set for the fun of it, the codes set for a reason OP. however OP in the end its your car and your money so go about it however you want to, all we can do is offer advice were not the ones out there fixing your car.


and btw dont get too upset about a few ppl on here saying its the driver, in our defense you have been posting as if your are very new to all this, you have stated on the first page that this is your first race car, that you are new to ls1's and never owned one or and f body. that and your 60 ft time points to the idea that you are new and do not know how to drive your car yet. yes you claim you didnt spin but its very possible that since your new to this car that you were spinning and you had no idea. and just because your friends have tracked the car as well doesnt mean that they know how to drive it either. dont get upset just pointing out a few things so you can understand why we on ls1tech are saying this. maybe post a vid of your runs if you have them.

My6speedZ

iTrader: (18)

I don't understand how you think a new exhaust will fix any of this stuff. Instead of worry about making your car faster and any mods you need to get it working properly.

You want to go faster? Make your car run at it potential, I've seen some shitty ratted out cars with loads of mods that run like **** because they have problems, ones that easily fixed at that.

OP you keep saying thanks for the help but your doing none of the things suggested to you. Instead continuing to drive it and take it to the track, worry about your codes and other issues. If you have faulty o2's that is the first thing to look at. Check your hoses get it scanned and check the data to see if anything jumps out at you or one of your buddies. You say your a tech but your sure not acting like one.

sreve

iTrader: (3)

Did the floor mat slide and wad up under the loud pedal?

youngbird

throttle body cable did seem a little streched to me gonna look atthat now all fuel pressure was ok but that doesnt tell me if the pump is bad i will have to try to drive it and check it some way and im getting exhuast regardless becuase thats what i want i will get this car running right its just a matter of checking thing im narrowing stuff down

im pretty sure my buddy knosw how to drive hes got hes car deep in the 10s

id have to look at this where would this good idea but was it running like **** i mean were thaere any side effects to it thanks ?

yes it did I took it off after the first run tho


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I8UR4RD

iTrader: (16)

as stated before you go to the track, you need to do some maintenance. first thing i did with my ws6, was swap the plugs, wires, gaskets, clean the TB, and check the codes for free....see what they were and then hit the dyno for a small tuneup. other than that youll need some good tires. and should go 13's in the 1/4 and 8.50's in the 1/8 depending on DA

homerz28

Did you ever say if it's an auto or manual?