IcemanG17

Heres a dyno sheet of a E92 M3 V8 with a supercharger....now thats a wicked powerband.... As an owner of a stock E92...it does have a fairly wide powerband.....with basically a torque table from 3000 to 8000 rpm....cool but almost useless in racing....

FlyingDog

As Brian said, GTS is not big out there. Try to realize that there are people who race outside California. In my region, there are no E30 GTS3 cars. The E30s are all GTS1/2, even the M3s. For GTS4 at 2900lb I would need 325-350rwhp to be competitive, not 290. 10:1 power to weight will not cut it out here. Plus, GTS3 is more competitive, with more cars, more regular drivers, and less 'big money' cars. Getting to just over 11:1 is the goal. If that doesn't work out, 8.5:1.

So, back to the original question... any stockish 4.5L or 4.7L dyno runs?

mark kibort

Matt, I know a lot of the folks that race out east. If there are no e30s where you are, consider yourself lucky, as it is a very popular platform, but I guess it hasnt hit the NASA scene as they are too much in their own BMWCCA scene.

GTS4 you dont need 325 to 350rwhp at 2900lbs to be competitive. At 305hp i was running SpeedTouring car times (top 10-15 times as of last year). Plug that into times at you track and see how those times would stack up at a track near you. at 295, which is very easy to reach, you could be right in that range, maybe .5 to 1 second slower as scot has found with his part euro 5 liter. also, again, scot does have a 50lb advantage, but has a heavy cage and hasnt done a lot of the weight reduction things i have.

I guess i do see your point about the GTS3 being a more popular group. You could just hit that min 11:1 hp range and have fun. again, the main problem is the weight compared to your competitors. you have the choice right now. it would be very easy to get that 5 liter short block and put it under a euro 84 motor. with the ECU you plan on running, it would probably be 300rwhp with out much fuss. I can guide you to how you could come off the track at 2875lbs with you in the car (if you are under 200lbs yourself) as far as weight reduction. Get the bigger tires too. 285x30s are crap themselves and have no sidewall and are terrible to tune around due to the short sidewall. you would be better off with the 275x35 tire. put the 305 on the rear, if you have a 10" wide rear rim. If you are worried about tire costs, visit the SpeedGT WC event near you with a truck and buy a couple of used sets for cheap. they are only a few tenths slower than new tires and will last most , if not all of a full season for you .

Now, as far as the dyno runs, I posted both of the ones you wanted. stock 81, a mostly stock 84, and some higher performance variants. if you want, i can post the truely stock 84 dyno runs too. basically, you can just take the 235rwhp and pull out 40hp from top to bottom. Ill post it if you are interested. However, after racing that with the BMWs for years, I can tell you i had a LOT more fun when the HP was a little better and I was able to compete with much better performing 911s and M3s. you are going to struggle with a stock powered 928 due to the weight. Thats 12 years of racing this platform with the exact cars you are going to be running against.

mk

QUOTE=FlyingDog;6229982]As Brian said, GTS is not big out there. Try to realize that there are people who race outside California. In my region, there are no E30 GTS3 cars. The E30s are all GTS1/2, even the M3s. For GTS4 at 2900lb I would need 325-350rwhp to be competitive, not 290. 10:1 power to weight will not cut it out here. Plus, GTS3 is more competitive, with more cars, more regular drivers, and less 'big money' cars. Getting to just over 11:1 is the goal. If that doesn't work out, 8.5:1.

So, back to the original question... any stockish 4.5L or 4.7L dyno runs?[/QUOTE]

mark kibort

ooth of those are nice curves, but forget about the torque table. it means nothing. look at the HP curve. both are peaky. if you have a certain hp, its better that it is flat, like what I have now with the stroker. remember, its the average HP that will buy you the most gains.

If you look at the curves i posted, you can see the shape of the HP curves. based on the rpm % drops due to gear spacing, that will determine the cars capability as far as raw acceleration over any speed range.

About those two curves . 550hp and 350hp. wow, right? well, peal back the onion and what do you really have?
that HUGE 550rwhp number goes down to 475rwhp as an average and the 350rwhp number averages down to 315rwhp.
this means THOSE are the numbers you care about on the track. (BMW would be shifted from 8300rpm down to near 6100rpm with a standard 75% rpm drop per shift)

mk

FlyingDog

We have tons of E30s, just not in GTS3. Chris Cobetto (2 time National champ) and Mike Skeen (current National champ and "Setup" star) race SpecE30 here. E30s are great little cars, but nobody runs one that can keep up in GTS3. The few that run GTS instead of SpecE30 battle with 964s and 944s in GTS1 and GTS2. E36 M3s are the dominant GTS3 cars. E46 M3s are the dominant GTS4 cars.

I like short sidewall tires. I have some Hoosier GAC 275/35-18s, but the 285/30 R6s are much easier to find, DOT legal, lighter, and slightly stickier. World Challenge runs craptastic Toyos. No thanks.

mark kibort

Ok, since you asked, and i posted some options and also got a feeling to what you are trying to do, here is my advice. since you dont want to enter the arms race, the GTS3 might work for you . But, you need to get a euro and pump it up to about 265rwhp. this should be easy. then, generally, you will be coming off track as we do with the normal lightening mods, at about 2950lbs. racing in the 11:1 and lower weight/hp class, you should be in the thick of thing. BUT, with that weight, you need to run 305s in the rear and 275s up front and slammed to the ground if you plan on keeping up with any hot e30s that show up as well as the 911s that fall into this catagory.

mk

mark kibort

e30s out here have been pretty strong, especially in the Jstock or Jprepared, as well as the hot Dmod group. again, these e30s run 2650 with driver and have up to 240rwp. its a very common platform and a known formula for any e30M3. it would be in GTS3. You would have no chance against one well driven in a 265rwhp 928. Just facts and experience talking here. again, thats ALL ive raced against for 12 years out here. many of these same drivers often make it out to the BMW races out east and compete. however, to compete against the hot e46s, or hot e36s, you need the holbert set up (305rwhp min). One of the faster e36s you will find is on several of the videos ive posted. generally, i would beat him, but one time he caught me and I couldnt get around him. (290rwhp and 2650with driver). Running R6s and toyos, it didnt matter, he was near the same time. (top 15 world challenge time for Touring)

Hey, if you like short sidewall tires. knock your self out. if you think toyos are "crap", thats interesting, also see what folks are running on them if they know how to drive them. If crap means 1 second, i would certainly buy a set, but i just havent seen that much of a differnce with the money pits and good drivers out here that switch back and forth between them. " crap" might mean you just dont like the style of driving that they command. If I can stay within 1 second of randy pobst on a new set of hoosier R6s, running a $100k e46 M3 built Grand Am GS racer with the same hp and weight as me in a old, beat up S4 928 running the toyos, they cant be THAT bad

I do think you would a fun time in GST3 with 265rwhp. i think you would be better in a 295rwhp 5 liter part euro running in GTS4, but you have to run the larger tires.

Skeen, national champ, and "set up " star? So. Did you watch the show? Ive never see a bigger group of crybabies and driving hacks!

mk

ShawnSmith

Random uninformed suggestion: Why not run within the GTS3 limits using a non-euro ~240 rwhp motor tuned for area-under-the-curve in the 4k to 6k region, combined with a lighter car in the ~2800 lbs ballpark to help with braking and handling? Is 265 rwhp and 2950 lbs a better trade-off?

mark kibort

The reality is that the car with the lightening mods we all know how to do puts you in the pits after a race at 2900 to 2950lbs. you cant realy get much lower than this unless you try. it woult be easier effort to get the 5 liter under the euro top end. PLus, you get into all sorts of other disavantages in aero drag for the long tracks and that lack of HP. I raced the 240rwhp 928. it doesnt work that well. I had a blast with my 5 liter part euro later on. In fact, it didnt do too bad against the Techmark M3 e36 PTG car at sears and laguna at 285rwhp in its first 2 WC GT races. (it ran in the back, but ran podium touring times) If you are going to run in GTS3, you need to get the 265rwhp. if you run in GTS4 you need to be near 300rwhp.

Matt,
By the way, World Challenge touring cars at VIR on toyos run 206-2:08 for the mid to back packers (10-15th) where a 300rwhp 928 at 2900lbs with driver would fall. what are the GTS times for VIR or other tracks in your neighborhood?

mk

IcemanG17

Since the class is pure power-weight based.....why not try to make a super light 928...I mean substantially lighter than most around...say 2500lbs or less using a 16V motor.... then you'd only need 245whp (assuming 200lb driver)...which would be easy to hit your 11-1 ratio

dprantl

In other words, break out the plasma cutter?

Dan
'91 928GT S/C 475hp/460lb.ft

mark kibort

The weight is a big deal. not likely there is any more to cut out of our cars than what I have sacreligously cut away. .

I think its easier to make 305rwhp than it is to weigh 2700lbs with driver.

Remember, you have to think in terms of absolute weight. thats 2/3s of the racing equation. weight is paramount, weight/hp is secondary. But, with big enough tires, you can close the gap to a point. aero is another factor. (aero to hp ratio) There is a sweet spot where the car works best .

In my opinion, he has two choices. 265rwhp and 2900lbs with driver, or 300rwhp and 2900lbs. (ie GTS3 vs GTS4). I think he will do better at 300hp in the next class where the weights and cars are bigger. All i did was race against pretty fast e46s for several years. WCGT, Grand Am cup GS, and BMWCCA cars. I was able to win more of the time against them with the Holbert car, even when it was down on power (ie 305rwhp). knock off some weight, and it could have done even better, but that would have required a plasma cutter!

some video of what 315rwhp buys you in a 928 vs an e46 racer bmw with headers, 275s, and some chip work.
http://www.youtube.com/watch?v=XICOJ...e=channel_page

mk

mark kibort

by the way, those bmw dyno runs, was the 350whp run yours mapped on the supercharger run? Or was it this guys car before the charger. if yours is 440hp, you would think it would dyno at around 375 at the wheels. I think you said once that it was in that range.

mk

dprantl

Stock is 414hp.

Dan
'91 928GT S/C 475hp/460lb.ft

IcemanG17

MK
That dyno wasn't my M3........most stock M3's dyno around 360-370whp on 100 octane gas...about 20 less on our crap 91 octane.....

Here is a link to RRI dyno test of a E92 M3...the 4 door M3 dyno'd basically the same

http://www.rri.se/popup/performanceg...p?ChartsID=768

I dyno'd mine with my new Corsa exhaust on 100 octane...but the dyno or car kept getting stupid....I need to dyno it again....however it made 300whp at only 5800rpm...when it should hit peak HP at 8050 or so..... that was on a mustang dyno too... but with all the computers in that car knowing that the front wheels aren't moving..the ABS-traction control (turned off) and about a million other warnings kept going off....

M3's tend to be underrated...at least the dyno runs I have seen on the M3 forum appear that way...