Lance J

hey tell them about the supra you spanked

DoubleNutz

Why not simply rear turbo that bad boy or Super charge it and dial up the boost you need to spank a 400HP 360Modena witha 240HP 928?

Could I be wrong...but these days perhaps the mods cost about the same as a NOS setup with proper mods and I think your engine will last longer.

IcemanG17

Sniper
That is a great time for a NA 3 speed auto!!! Your car has to have some type of serious engine work...my guess is a 5.0L+ bottom end with Euro intake-heads-cams...plus the stuff you did! With your lightweight car & those type of numbers you have to be at least 310 (Euro spec) crank HP...probably closer to 330....have you dynoed it? Again my guess is 270+ to the wheels

You should post your times at www.dragtimes.com I posted my runs from march...my best was a 14.54 at 95mph...that was with zero power braking..just floor it and go! Not bad for a near stock (only RMB), automatic full weight S4 (3500+ myself)...I figure with some tweaks and a better launch I could drop it down to 14.3 or so...maybe better?

Your 0-60 seems kinda slow in comparison to the 1/4 mile times...typically my G-tech reads between 5.9 to 6.1 for my car (6.12 on the 14.54 1/4 run)... But the 55mph shift does slow the times!
Brian

m21sniper

BRIAN: "Sniper
That is a great time for a NA 3 speed auto!!!"

Mine is a 4 speed, and always starts in first regardless of throttle position. I assume the first owner paid good money for that neat little feature, because as i understand it that is not normally the case. It also brings into play the very real possibility that my trans had the lower 2.50:1 gear ratio retrofitted vs. the stock 2:20.
Doesn't sound like much, but a .3:1 lower final drive ratio is actually pretty significant. I also lowered the effective final drive ratio myself a bit(about 3%) by switching to a smaller OD tire(245-45-16), which is also 20mm wider than stock.

"Your car has to have some type of serious engine work...my guess is a 5.0L+ bottom end with Euro intake-heads-cams...plus the stuff you did!"

When i raced Lance he suggested i might have a 5.0 bottom end too. My block is marked M28/20, which is the correct OEM part number for an 83 US, but it's possible it's got some sort of stroker kit in it. I've never had the Valve covers off, so i've no idea what sort of cams i have. If i ever have to pull the covers i'll be sure to write down the cam numbers and post them.

I've also heard from a lot of people that own and have driven 83s that they're freaks, much faster than the published performance listings. I would buy that if i hadn't crushed Heather's 83 US by so much.

"With your lightweight car & those type of numbers you have to be at least 310 (Euro spec) crank HP...probably closer to 330....have you dynoed it? Again my guess is 270+ to the wheels"

I'm not a big believer in dyno's because you can take the same car to three different shops on the same day and get three fairly widely varying dyno numbers. I calculate HP by known track ET and trap speed, then split the difference. That gives a decent enough guesstimate for my purposes. All i really care about is the actual ET though. When ya run a 13.67 you don't need a dyno to tell you you're making lots of power, it's self-evident.

"You should post your times at www.dragtimes.com I posted my runs from march...my best was a 14.54 at 95mph...that was with zero power braking..just floor it and go!"

I ran my best time launching at 1600rpm @ 22psi in the rear tires after a nice burn out, with 50psi in the fronts. Try duplicating that next time you go, i guarantee you'll pick up a 1/4 second or more.

"Not bad for a near stock (only RMB), automatic full weight S4 (3500+ myself)...I figure with some tweaks and a better launch I could drop it down to 14.3 or so...maybe better?"

Maybe as low as a 14 flat if you set the tire pressure and run 100octane gas and bump your timing way up to take advantadge of it. At the track it's all about traction. Our 928s have about a 2300rpm stall converter, so if you can get full traction at 2300rpm you're going to run a much faster time than launching from idle. Perhaps as much as a second if you're lucky. I've seen cars make no change other than slicks and cut that much off their ET before. 80s-90s mustangs GTs are a good example of that. They're seriously traction-challenged cars, and benefit massively from a swap to nice wide slicks.

"Your 0-60 seems kinda slow in comparison to the 1/4 mile times...typically my G-tech reads between 5.9 to 6.1 for my car (6.12 on the 14.54 1/4 run)... But the 55mph shift does slow the times!"

The G-meter times were actually recorded before i did my final weight savings job(i borrowed the g-meter off a friend, i don't own one of my own) or my last day at the track, and i cut a good 125+ pounds off the car since that time(driving seats, dry cell battery, and yanking the A/C system). I'm sure it's a few tenths faster now, but i've not verified that in a timed run. My real powerband is 2d gear. My car pulls very hard all the way to 6500rpm in second, which equates to 98mph. I shift to third about 100 feet short of the traps right in the heart of my motors power band, and accelerate like mad the last 100 feet.
My best trap speed is a 103.1, which oddly enough came on my slowest ET run of the day because of wheelspin at the line. I spun em for a good 20 feet and as a result the motor was in the heart of it's power band when i finally got traction(just shy of 3000rpm IIRC). That allowed me to accelerate through 1400 feet much harder than i would normally do with a good launch from 1600. Helps the trap speed, hurts the ET. On my 13.67 run i think my trap speed was a low 102. It's been over a year, so my memory is a bit foggy. I guess i should dig out my timeslips for the day, but i'm lazy.

m21sniper

DoubleNutz: "Could I be wrong...but these days perhaps the mods cost about the same as a NOS setup with proper mods and I think your engine will last longer."

I would LOVE to turbocharge my 928S, i've owned several turbo cars, and i love the rush of an automatic car under boost. But i highly doubt i could turbocharge my 928 for even 300% more than the cost of a 75hp nitrous kit.

If anyone knows of a way to turbocharge a 928 for under $1000 bucks, please, DO TELL.

m21sniper

LANCE: "hey tell them about the supra you spanked"

Hey guys, i spanked a Supra.

I think it was a mid 90s, never been too up on those, but it was the TT bodystyle with the big wing and it was definitely a turbo...i heard the unit whistling when i was driving next to him before we ran.

Anyway we both left the light at a slow pace but i'd held my 928 in 1st gear in anticipation of him jumping on it(which as i pointed out on the other forum i'm sure that instigated him to run me), so the instant i heard his engine note change pitch at about 30mph as he went WOT i was already at about 3500rpm in 1st and stabbed the throttle. My shark EXPLODED ahead of him before his turbo had a chance to respond to engine load, and i caught him with his 'lag down', lol.(I've had that happen to me in my T-Type a few times, it's very annoying) I opened about a 4 car length lead by 60, and held that margin until 100 when i let off. At the next light he pulled in behind me instead of next to me, so i guess he didn't want to try a standing start(which to be honest, would've given him a much better chance).

LOL, sissy.

Normy

Sniper- how 'bout a couple of pictures?

N-

m21sniper

Sure. I'll start a new thread titled "Pix of snipe's 928S"

Still no luck on getting any input from a 928S Nitrous user here though....

bcdavis

I disagree that NOS will toast your engine sooner than a turbo or supercharger.
The benefit of NOS is that it only strains your engine with the extra horsepower when you want it to.
The rest of the time, it's stock.
If you run a turbo, or supercharger, you are pushing extra pressures and extra strain
at all times. It's far more likely to wear out a boosted engine quicker...
The stuff about people melting down their NOS engines are stories
by people who don't know what they are doing. The same thing can
happen with boost, when idiots just strap on a turbo, and don't
do any fuel enrichment, etc... The same happens with NOS, if
you just dump it in the manifold, without proper tuning. But if it's
properly set up, it's just as reliable, and there is less strain on the
engine over the engine's lifetime...

m21sniper

"Oh, that explains it.... G-tech pro is only accurate if you enter the "exact" weight of your car. If your of by even 50lbs, it will give you optimistic numbers..."

Correct. Unfortunately the race track does not give 0-60 times, but rather ET to distance times. I've been meaning to take my Shark to the local salvage yard and put it on the scales, but so far i've managed to be too lazy.

IcemanG17

Sniper
Typically truck stops have scales...some will let you weight your car on them for a small fee...my local scale is $8, but it only reads in 10lb increments?

Some of the local Norcal928ers are planning a 1/4 night in the fall when the weather gets cooler.....no sense trying in 100 degree heat...times won't be good!
Brian

m21sniper

Actually, although you lose HP in the heat of summer the asphault gets so hot and sticky that it almost makes up for it on most cars ETs.

But i must say from my own perspective that sitting baking in the heat in the staging lane waiting your turn at a busy racetrack aint exactly fun either, lol.

mark kibort

well said.

mark kibort

again, it depends. i just posted dyno runs at 82 degrees, and actual was actually better than SAE corrrected. I would love to think that the car could run 5% greater hp at 50 degrees[, but ive done dyno runs at 60f with the same results (actual) dont know why, but it sure doesnt seem that high temps hurt much. in fact, my fastest times at Laguna have been in 85 to 90 degree days. (and that goes for Thunderhill at 100F) trade off with tire stick???? thinner air, less wind resistance??? who knows. But, there are trade offs

mk

QUOTE=IcemanG17]Sniper
Typically truck stops have scales...some will let you weight your car on them for a small fee...my local scale is $8, but it only reads in 10lb increments?

Some of the local Norcal928ers are planning a 1/4 night in the fall when the weather gets cooler.....no sense trying in 100 degree heat...times won't be good!
Brian[/QUOTE]

DoubleNutz

Hey Mark...are you bringing the Holbert Car to the Sharks in the Hood event? We are hoping you can bring it up for a photo and show and tell session. Don Hanson will be there.

p@

.
.
.