Utinator

So, you're saying an LSA swap isn't easy?

Utinator

I was talking about the Altima, but that Eco Boost walks off too. I'm sure my 2500 HD (LLY) would smoke this car with the performance tune. That Duramax don't play.

JD_AMG

Something is seriously wrong with your car if it is having troubles with the above cars...
Again, a bone stock LS1 fbody is good for mid to low 13s @ 105+mph. Some have gone high 12s totally stock (manual trans).
Get the car running right first, there is no need for an engine swap, especially if you only want to run 12s.

RPM WS6

iTrader: (3)

^ Good advice above.

Car needs to be sorted out, it's missing about ~90hp based on trap speeds. My 3rd gen used to trap around 95mph with 240hp at similar weight with 3.27s. LS1s all made 345-350hp when stock and fresh. Could be that you're not seeing full WOT, could be that the transmission isn't sending full power to the wheels, or it could be that the engine just isn't making the power it should (for any number of the reasons already listed in this thread, not all of which have anything to do with an internal problem.) Further investigation/troubleshooting is needed before any mods IMO.

Utinator

I plan on taking to a shop where I can work on it tomorrow. The goal is to check the compression and change the plugs/wires. Hopefully that will help.

What should the compression be on each cylinder?

RPM WS6

iTrader: (3)

Personally, I would not be checking compression before checking fuel pressure and fuel trims/timing/KR data and verifying that full WOT is actually occurring (plus the super basics such as air filter and MAF dirt/blockage). Some of that will require a comprehensive scan tool, but fuel pressure will need to be checked under load (gauge taped to the windshield works fine for this.)

When I pulled the stock 100k mile plugs out of my '02 car they still looked great. Changing them did nothing to improve power or MPG. So, at similar mileage and with a stock engine, unless your car has seen some rough service conditions and/or chronically horrible quality fuel I wouldn't expect to pick up that much lost power from a plug change alone. If they were heavily oil fouled from valve seals or bad rings or something like this (enough to cause such power loss), I'd expect you to have some misfires and rough idle conditions as well. Misfires can also be tracked with a scan tool. If they were excessively carbon fouled from lazy O2s and/or a dirty MAF, you'd probably see some evidence of this with bad MPG and also fuel trim data that's far from optimal in every cell.

You mentioned that the car seems to run great (so I'm assuming shifts great as well?), but trap speed throughout the run suggests that a bunch of power is missing. IMO, the best place to start in that case is with WOT verification (both via TPS and manually, if you can get a helper, including air filter and MAF inspection for excessive dirt/blockage) and fuel pressure/fuel trim data.

01CamaroSSTx

iTrader: (3)

Remove all the plugs so the motor turns over easier. On my LSX 427 each cylinder was in the 180s after the fifth turnover.

Utinator

I don't have access to that kind of equipment. The shop I'm going to should have a compression gauge. By the time I'm done fighting those plugs and wires, they will need to be changed. I'll report back with my findings.

cookseyb

Why don't you take it to a shop that knows WTF they are doing and be done with it, much cheaper in the long run. FWIW...

Mart00SS

iTrader: (19)

As stated above do not get any mods, you need to figure out why it is down on power. My car in stock form ran 13.5 @ 105 mph just as everyone else has stated.

RPM WS6

iTrader: (3)

If you're going to a shop without a fuel pressure gauge, then you're going to the wrong shop. That is a basic tool for any automotive repair shop. A plug swap isn't going to find a missing 90-100hp unless the plugs are so bad that you also have misfires (which could be seen with a scanner - another tool that any good shop should have, but it's understandable if they don't have comprehensive software on a laptop for this - nice to have, but not as fundamental as an FP gauge) and other general driveability issues.

I wouldn't do a compression check before first checking fuel pressure; a comp check is much more work and less likely to be the cause based on the details you've given so far. Verifying true WOT and air filter obstruction is also pretty basic and something that should be looked at before even thinking about touching spark plugs. I do realize I'm sounding like a broken record now and you're obviously not interested in that advice so I'll move on.

Good luck, I do hope you get the problem sorted out. These cars are a lot more fun when they have full power.

Utinator

I'll have to pay someone to do the fuel pressure check. I went to a shop where you rent the stall/lift/tools, but do the work yourself. They had a compression gauge, but I couldn't get a reading. The gauge/needle bounced around so much that I couldn't read it. The engine kept trying to run, even though I pulled the fuel pump fuses. I thought this would be an easy task, but it turned out to be a PITA like everything else on this car.

I did replace two plugs/wires while I was in there. I also greased the rear suspension like BMR said to do. I was able to get someone to hold the gas peddle down while I checked the throttle body. I verified that it is opening all the way. I guess the trip wasn't a total waste.

Utinator

Where do I find this MAF thingy? If it's accessible, I can try to clean it. I just don't know where to look, or what it looks like. I'm more comfortable working on jet engines than this internal combustion contraption. At least with a jet engine, I know where the compressor is. I still haven't found one on my car.

98CayenneT/A

Green arrow. It will have a harness on it.

RevGTO

iTrader: (12)

Utinator, similar things have been said to you over and over again in this thread. Yet they seem to bounce off of you like water off a duck. I'll put it to you as simply as I can: you need to learn your car. Browse this site, search, and read, read, read. Then you'll begin to understand and spare yourself chasing your own tail and wasting tons of money.

I know whereof I speak. Fifteen years ago, I came upon this site from the old school Pontiac world. I knew nothing of electronically controlled engines. Yet step by step, I learned, experimented, and worked.

Start with the basics first and work your way up. End of sermon.

Utinator

Yeah, my engine doesn't look anything like that. If it's forward of the throttle body, I should be able to get to it though. Thanks.

bigbomber5

http://www.ls1howto.com/index.php?article=10

That is a good example of the MAF in a pretty much stock engine bay. Same location and everything, just may look more similar to what you are looking at.

mikedamageinc

iTrader: (49)

^^^ Your engine doesnt look like that because his has been modded. Like everyone else said you need to get down to basics. It doesnt sound like you did the compression test right...remove plugs, injector fuse, fuel pump relay, connect gauge, turn over engine a few times then look at gauge not while turning engine. It will max out and that is your reading. There is also a decent F body presence in Richmond that someone might be able to help you, maybe a facebook group.

For the record I ran at Richmond dragway with lid, filter and exhaust, no tune running mid 13's ~106 while babying every shift (M6 no drillmod/no adjustable master), over 200k mile original engine, ~150 psi compression all cylinders within 10psi, and on crappy street tires. At the time it should have dipped 12's if I had known about the factory clutch issues, but that's why you read this site for all its worth!

Forget about suspension and all that, your engine isnt performing, and/or possibly your slushbox has issues too. I would recheck compression, new plugs and wires (cheap tr55 and GM red wires are fine), clean the MAF and throttle body, and change trans fluid

fst100

iTrader: (5)

no disrespect but how much car mechanics does OP know and understand if they're asking what and where the MAF is? if not much then it may be best for OP to do some reading and gaining knowledge prior to poking around on his own in and around his car. just as a precautionary measure that's all.

DANOZ28

iTrader: (1)

if he has clogged cats would that drop his trap speed? tune could be off. start with the basics , then air lid plus catback or atleast good muffler. then add your stall with tune for max performance. i would also address the rear suspension by adding welded sub frame connectors plus LCA's & better tires. most would add headers if allowable in your state (no inspections). should be running mid to low 12's all day long. just my one cent