JDS99Z

I've got my first LS1. 1999 Z28 Convertible M6. Picked up with 25500 original miles and the original Goodyears

I'm just trying to understand the power on this car. On the window sticker it has the factory Z rated tires, ASR and the Hurst shifter. It also has the Ultra Z hood matched to an SLP lid, what appears to be a K & N filter and a 3 inch stainless cat back pipe running into what looks (but doesn't sound) like a stock muffler with stainless steel quad tips

I'm just wondering what I have here. Drives awesome and is tons of fun. My daily driver is a 2013 HEMI Charger. Will this car run with it, crush it, lose to it? It's too nice for me to beat up and find out....yet

Firebrian

Don't know what an ultra-Z hood is. But, regular Z28's came with a simple flat hood. The 320 hp Camaro SS came with the fresh air inlet hood. Z28 rated for approx 305 hp stock (5.4 zero to 60, 13.9 at 102.5 mph in the qtr per Motor Trend). With your fresh air and exhaust set up you might have another 20 hp added. The Z28 is 600-800 lbs. lighter than your Charger, and more streamlined. A well tuned stock LS-1 can get into the mid 13's for the quarter mile in the 103-106 mph range.

I think your standard Hemi Charger R/T (370 hp) could be the slower car, but not by much. I'd say the Z28 runs with it pretty well. The Hemi SRT8 is certainly the fastest. These old LS-1's do surprisingly well against the newer Challengers, Camaro's, and Mustangs in the 365-425 hp range, especially considering how much heavier those newer cars are. A little bit of tuning with standard bolt-ons for the LS-1 and it's up in the 375-400 hp range. Many say the LS-1 was a generally underrated engine in order to give the Vette bragging rights at 350 hp.

JDS99Z

Thanks for the reply the Ultra Z hood was from SLP too. Fresh air scoop at the front that pushes air into the bottom of the lid

Firebrian

So your car is probably similar to the HP of a '99 SS. The car might have a cam and other improvements to take it to 350 hp+. The LS-1 is known for being quite tunable and easily adding HP. The 1999 Z28 and 2013 Charger are pretty even overall. I haven't owned a newer Mopar yet but played with the Mopar B-Bodies from 1991-2004 (GTX's, Roadrunners, Super Bee, Challenger R/T 440-6, and Coronet R/T vert).

http://www.musclecarfacts.com/chevro...59-1999-camaro

RPM WS6

iTrader: (3)

First thing to understand is that the factory ratings of 305/310/320/325 horsepower are meaningless; all LS1s make between 345-350hp depending on model year, this is true for both Corvette and F-body. GM simply underrated the F-body version of this engine, and this has been proven time and again with consistent dyno results of stock cars that often make as much RWHP as what their "rated" crank horsepower had been.

In the '98-'00 years, there was a slight difference in cam profile between F-body and C5, but this didn't result in any significant difference in power (the purpose seemed to be mostly to allow for the absence of EGR on the C5, perhaps due to packaging/space concerns.) Starting for model year 2001, the C5 LS1 and F-body LS1 became identical engines, both using a cam profile borrowed from the LQ4/9 truck engines, and an intake borrowed from the Z06's LS6 engine.

The SSs don't make any measurable amounts of additional power in base form, but when optioned with a dual/dual catback or additional Blackwing lid (both could be ordered on a new SS through SLP, though the latter wasn't available until 2002) they are good for about an additional 15hp or so. The optional dual/dual catback and Blackwing lid are comparable to any of the aftermarket catbacks and lids. The factory SS hood and 0.50" larger tail pipes (the only improvements on a base SS) don't make enough different to be measurable.

As mentioned above, on average a stock LS1 will run somewhere in the mid to low 13s at about 103-106mph, with the M6 cars being just a bit faster than the A4s when properly driven and all else being equal. Having said that, the fastest stock LS1 F-body on record is a '99 M6 Z28 which ran a 12.89 at, I believe, 108+ MPH. So there have certainly been some very fast stock LS1s, with the right driver and right weather conditions.

JDS99Z

Thanks. I'm rusty on a manual but I'm starting to remember why I like them So much

DANOZ28

iTrader: (1)

beware of revving stock valve springs too high. my stock 99 at about 5700 rpm they started fluttering / floating. look down the throat of your throttle body & see if the EGR thing is hanging down. install university shows you how to cut it off (free mod). search 4 an old article may 2004 super chevy "ls1 dos & donts"