I've got a lightly modded A4 '97 Camaro with these mods:

K&N, Hotcam kit, SLP shorties, Yank 3000, Flowmaster catback, 3.73's, LT4KM

It dyno's at 274rwhp, somewhat less than it should. A local buddy who's a wiz with fbody's has been helping me out, including a dyno tune with LT1Edit. Autotap data looks fine, no codes, the car feels fine, the dyno chart looks fine, no knock. We can't find anything to indicate a problem (aside from the low dyno number).

At this point we've already changed lots of parts to no avail and he's thinking it needs to be left at the shop for a few days to get into the motor and see whats going on. But, that will cost thousands. So I'm at a crossroads. I figure I can do one of two things:

1) Drop another $6k into the car to get better heads and figure out what the power problem is over a few days of shop time.

2) Enjoy the car for another 8 months as it, then sell it and use those proceeds (and the $6k I would have spent on more mods) and get a used '97 LS1 Vette for ~$20-22K.

The issue with choice #1 is that I'll spend all that skrilla and we still may not figure out whats wrong with the low power output. The issue with choice #2 is that it cost a little more, but I'll have a better platform for future mods.

Anyways, I have no idea what to do I just wanna see what y'all would do in a similar situation. Thanks!

 

$6K for heads and "shop time"? If I were you I would try and figure out the problem myself. You obviously are lacking some power. Are you running through the stock y-pipe? Converters eat up a little hp. SLP shorties aren't exactly the best flowing. What parts have you changed to no avail? He shouldnt have to tear apart the engine to find the problem. I dont think you realize how resourceful this board is. Just ask, the people on the board will be more than happy to help.

 

6K for heads and shop time? Are these heads cast out of gold or something? 274 rwhp is not to shabby. I would maybe go with an adjustable fuel pressure regulator and better injectors if you havent done that already. It seems to me that your local F-Body whiz is trying to rob you for more services and money. Check another shop and get a different opinion you might be suprised.

 

wow 274???? thats what I dynoed with just a cutout.

I would check obvious things such as plugs, wires etc. Get it on a scope to see what cylinders are doing what. I would also check to see how reputable the dyno shop was. I have heard of some shops putting out HUGE numbers and some small numbers. Don't dump $6k into it. heads only cost $700-$2k.

 

You might also want to several other things before you do such drastic measures.

Has it been tuned?

Stock springs or are you using the springs that came with the Hotcam kit? I ask this because I was getting some serious float with the springs that came with my old Hotcam kit....they are barely adequate for even a cam as small as the Hotcam.

Check all the basics....spark, air, fuel.

And as mentioned before....those aren't the worst #'s I've ever seen. Especially with shorties...and if you still have the cats on.

Also...dyno #'s aren't everything...especially in an A4. You could have a little TC or tranny slip. The thing that should really matter is what does it run at the track?

 

K, lets see hear. Is your k&n the fipk? Or just the filter? If its just the filter you need to get the whole cai not just the filter. Although i think the flowmaster exhaust sounds good. It is not really the greatest flowing exhaust system out there. The TC will make you have a little more loss in the drivetrain. Also there is not a huge gain with shorty headers first of all, but the dual cat shorties even show less of a gain. I'm assuming you got those because you don't mention only having one or no cats. Like Ghost said if its just the cam and not the kit you may have some valve float. The #'s are not the best or anything but they arn't really that bad. Auto's show less hp.

 

Thanks for the replies guys! I probably should clarify some things:

1) The $6k figure was for more than just heads. He was gonna take apart the motor completely, re-ring it, etc. Basically a motor rebuild.

2) The guy helping me out is Elis, he's pretty well known around here. He knows fbodys backwards and forwards, and has worked on mine many times even at his house on his own time for no charge. He's definitly legit. His own ride dyno's at around 395rwhp NA and runs 11's, not too bad to an LT1!

3) I have the whole hotcam kit (cam, springs, rockers) and the K&N FIPK.

I've posted here before and got good replies. We've changed many things so far, off the top of my head: plugs, wires, injectors, O2's. We have tuned it as well. We use autotap and LT1Edit and Elis sets all the tables. It originally was 254rwhp but we got it to 274rwhp after tuning.

I do need to stay emisions legal so I kept the stock cats/ypipe and went with SLP shorties. They aren't the greatest and the converter will soak a bit. But the numbers are still pretty low. At a dyno day many months back, my ride was basically at the bottom power wise (aside from a late 60's Camaro which dynoed even less than mine). There was even an A4 LT1 with the stock cam and light mods that dynoed more than mine! So something strange is afoot. Also, people on this board typically seem to dyno well over 300rwhp with A4's and hotcam kits.

The hard part is that there is nothing obviously wrong with it. It runs great and has been very reliable. None of the data we've gathered suggests any problem. We can try guessing at more parts but who knows. The big wildcard here is that the hotcam kit was originally installed by the dealer so we are suspicious of it. It was a really cheap install at the time, but now I can't help but wonder if they mucked something up.

I haven't gone to the track, but I do take out LS1 Vettes on light to light races thanks to the converter, gears and 315 nittos in the back. First gear I get a big jump, a small jump in second gear, but by 3rd gear I'm no longer gaining on them.

 

Well, I'd venture to say that the stock y-pipe and cat are hurting you, but here's another question.

Have you don't a compression/leakdown test? You could have poor compression and the car could still run fine.

 

FWIW, it's been mentioned here before that the dual-cat '96-'97 SLP shorties are not much better than the stock manifolds. Mainly due to the fact that the driver-side's header-to-cat distance is extremely short and the length of the primaries becomes really short on that side. With your configuration, I think that you have quite a bit to gain by going to a good set of mid-length or long-tube headers along with high-flow cats. I'd be willing to guess that that single change would up your output by 20-30rwhp.

That's $0.02 from a bench-tuner...

Definitely have a compression test done though, just to take that out of the possibilities.

 

you still have stock rocker arms and springs?

 

Nope, I've got the rockers and springs that came with the hotcam kit. We haven't checked compression, but I've now added that to the list of things to check.

Wow, I didn't realise that my headers/cats/ypipe setup could be costing me that much power. I'm not sure how much I can do about that and stay emmisions legal, but I'll search the board and see what I can find. While I'm at it, I'll browse the Vette board and see what gotchas those cars have.