tannin

So I took my '98 ws6 to fbodycentral for my first set of power adders. Figured I'd break up the work I wanted done in to three or four mostly-affordable trips. This was going to be the exhaust trip, with a new cam/TC to boot.

the work:
kooks 1 7/8" LTS
ORY
Comp Cams 228/228 lift .588/.588 duration 114LSA
Dual valve springs
vig 3600

I know the headers are bigger than I need, but I'm aiming for a 90mm intake and some good heads, when cashflow allows.

They took a couple days longer than expected, and I finally got a call last nights saying it dyno'd (mustang) at right around 300 rwhp. So far, nothing has been done to the intake, even the lid, so I can see restrictive airflow, but less than some cars run stock!? That seems a bit extreme. (They've also noted the stock filter is pretty darn dirty).

Add to that reports of detonation, due to, according to the guy on the phone, possibly some carbon buildup on the piston heads (is there any vaguely cost-effective way to clean this? is seems legit from some brief web searching), and thus a conservative tune, and it looks like I've just thrown a bunch of money down the drain.

They've now recommended I go ahead with a 90/90 setup, a lid, and a cutout, using a PTM (i think) 90mm TB, which I'd not heard of, and have so far only seen on the texas-speed page, in hopes of something like 340-350 unlocked rwhp, which still seems low.

Any help anyone? I need to call them back shortly and either schedule work or plan to have the car picked up with apparently a pretty messed up setup.

brad8266

iTrader: (23)

Damn thats low, even through the high stall and a mustang dyno. Find out if they locked the converter or not. Also the detonation is probably killing the power as well as you not being tuned. Carbon buildup can be cleaned up by running seafoam through the intake manifold, it will go through and clean out the chambers for ya. Be sure the car has a tune up too (plugs, wires, filters.) You will need a tune to get the most power out of the cam also.

tannin

The TC was unlocked, but they tuned before they ran it. It was just a conservative tune to handle the detonation though.

KY Z28

iTrader: (1)

from my experience, Mustang dynos read much lower than a DynoJet or other comporable dynos (seems to be about 25hp on average). that, combined with the fact that you have a 98', an auto and what sounds like a car that needs some good routine maintenance, you might not be as bad off as you think. besides, peak numbers are not what matters, the relative gain from one part to the next does. did you dyno the car before the mods?

and what the guy was telling you about the carbon build up is no BS. carbon build up effectively increases piston height and, therefore, the compression ratio. higher compression will cause detonation if not tuned for accordingly. however, that said, it would probably take a LOT of carbon to cause detonation.

i would put new plugs and wires in, get a lid put on and have a compression and leak down test performed. re-run the car and then see where you are at. you will also most likely need a good tune with the headers and cam also. good luck and i hope that helps

also, dont worry about all that stuff he was tellin you that you need. he is just trying to sell you expensive parts. just get the car in good working order with a good tune. that will really help. then you can think about new intake mani and all that...

FSUNole17

iTrader: (18)

i honestly think a lid is holding you back right now, that is most people's FIRST mod and it wasnt yours. nothing wrong with that, but in order to take advantage of those big headers and get the exhaust out, you gotta get more air going in first. buy a cheap lid and THEN dyno it, should pick up more than most because you have already done the other bolt on mods

Mike2000Z28

There are alot of minor things you could to get the numbers up, change the plugs/wires, pcv valve, air filter, fuel filter, and so on. If the car has alot of mileage then chances are you need to have your heads cleaned up and maybe the carbon has built up. I found that my almost 90k LS1 had pretty dirty heads when the cam and springs got installed, where the owner before me had used crappy oil before I got the car with 45k. I try the little weekend projects (i.e. wires, plug, filters) first cause they are really cheap and then take in on up the price scale.

brad8266

iTrader: (23)

yeah i didnt even notice you dont have a lid yet. The stock lid sucks *****, throw on an aftermarket lid.

Detroitmuscle

iTrader: (16)

I don't think you should worry too much check out my numbers in my sig.

brad8266

iTrader: (23)

What times do you run??

Detroitmuscle

iTrader: (16)

I'll be hitting the track tomorrow and will let you know then. I ran a 12.6 at 115 with a shitty 2.2 60' spinning like a bitch on a mustang dyno but now have a set of Nittos so they should hook a little better.

tannin

I've got them doing the top end clean and redynoing with a lid to see if i can get the numbers up some. Once I'm certain I've got everything in a stable state I'll work on the rest of the intake. As long as we don't get much rain I'm fine, my backup vehicle is missing a roof (and doors, windows, 2 wheels, etc.).

Thanks for the support though, being told you've thrown a few thousand for a brand new 300rwhp setup....

SiL3NtXWS6

iTrader: (17)

That's on par with my friend's mild H/C ls1. More proof that dyno numbers don't always mean something.

Grimes

iTrader: (3)

1. get a lid
2. maybe run a can of gm top end cleaner
3. change your spark plugs
4. change fuel filter
5. change air filter
6. redyno!

good luck man.

Detroitmuscle

iTrader: (16)

Locking up the converter will make a good amount of difference in itself but Mustang dynos and stalled autos don't put out great numbers. Just worry about the ETs that is all that really matters, dynos are for tuning.

Wyckedcamaro

iTrader: (2)

numbers are for bragging rights.

I know a get pushing 360 rwhp and putting down LOOOOOOW 11s on his vette.

You will be happy with a tune and the converter.. Get some sticky tires and see what you do at the TRACK since thats all that matters unless it is a dyno queen

Redneck Z

iTrader: (3)

Yeah......definately get a lid, and the longtubes are too big, even with heads. The 1 3/4 headers seem to be better even on a mild stroker combo.

TheBlurLS1

iTrader: (8)

The headers may not have gained him any power, but they are certainly not hurting his numbers. SUX2BU tested this out a few weeks ago.

I think your problem is tuning related. I've never seen anyone with a stock lid do a cam and headers, so I can't really say if the lid is holding you back or not. You can expect 10-15rwhp out of it considering you have other mods. It should scream, carbon or not. Unless that carbon is 1/2" thick. You could try to use some Sea Foam (just like GM top end cleaner), to get it running right.

Mine put down 371rwhp on a Mustang dyno with a cam, which is about 25rwhp off of what it would have made on a Dynojet. Even with the stall, I'd expect much better numbers than that. You could take it somewhere else who has a dynojet, or just a different dyno, and try it out. You're right about people making more power stock. I've seen lid+catback cars make 320rwhp easily.


Where are you located? Is the shop that tuned it a board sponser?

tannin

Located in northern virginia, I end up going to fbodycentral.com in baltimore. I'd asked around on the old ls1.com forums, and found nothing reccommended that was any closer. Rapid motorsports, an extra hour or two away, failed to return a single call.

FBC seems to have some sponsored cars with pretty good numbers, and I'd neard nothing but good things about them, but if anyone has other suggestions...

FSUNole17

iTrader: (18)

LS1.com= stick to ls1tech, you, your car, and your wallet will thank you

tannin

This was months ago when I was having the first suspension work done, before I'd discovered ls1tech. That said, VA isn't listed on the regional forums here :-p