Turbo-era F1 -- facts and fictions?

Or, "Pardon me, good gentlemen. Would you kindly share your knowledge of the extreme motors of Formula One's turbo era?"

(Yeah, not grassroots at all. Except that they might have been turbocharging used BMWs, which is so GRM it makes my head hurt.)

So I was watching the 1986 Australian GP last night, and digging the cars. That was the last season before they started limiting the cars to 4 bar boost (~60 psi). In '85-'86, they were apparently using some exotic fuels and 5.5-6 bar.

Racing, the internet, and the passage of time being what they are, there are all kinds of wild claims out there -- BMW's motor made 1450 HP in qualifying trim (and quite a few manufacturers claim to have had at least 1200 HP in qualifying), BMW built the motors on used road-car blocks (60K mile motors worked best?), at some races, telemetry revealed that drivers never used full throttle.

How much of that is fact, and how much fiction? I'm not an engineer, but the HP seems not impossible. Small-displacement NA motors (like bikes) get 125HP/l in street trim... stuff 6X the air in there, and build it to last 2 laps on rocket fuel... well, outlandish HP numbers seem about right. But used blocks?

I found a link to a dyno sheet for a rebuilt BMW M12/13, which shows 802 HP... at 3.3 bar, at 9700 RPM. So what would happen if they cranked up the boost, and ran it to redline (supposedly 11,500+)?

What's the real deal on these motors -- or what are your favorite tall tales about them? Matt

The fuel was nitromethane like drag racers use. The high horsepower was only during qualifying and the engines were changed immediately afterward. So the high HP was attained although I am not sure of the exact output.

I have never heard of the used blocks though.

ive heard of the used blocks. BMW would leave their block to sit outside to be rained on and rust, because rust straightens the metal?? i dunno, but anywho thats what ive heard

I've repeatedly heard over the years that they sourced used blocks because the heat cycling was good for them. who could substantiate that sort of thing by now? idunno.

The British magazine MorotSport had a special issue on turbo era F1 a couple of years ago. It was really cool, articles by most of the people who were there and made it happen. I'm working from memory here (my issue got misplaced somehow, so I can't refer to it), but to the best of my memory:

Grodon Murray, who designed the Brabham-BMW, intentionally designed the car with about 70% of weight on the rear wheels, figuring that since the boost hit so hard, that no driver would be able to modulate the power effectively in corners, so he aimed at absolute maximum traction, intentionally creating a point-and-shoot car - which worked like a charm and won the championship with Piquet, who I consider to be a good, but not special, driver.

BMW engine man (maybe Paul Braque?) reported that the F1 engine was indeed based on the street block,and that they did use carefully selected used blocks (M10? - the 2002 series, anyhow). He couldn't report how much max power they made in qualifying trim, because they were off the scale of their dynos (which I THINK maxed at 1300 hp). The qually engines were good for about 5 laps, including in and out laps, and were then ruined - and so were the gearboxes. He told one story of Piquet coming in after qualifying with a halfshaft twisted 180 degrees! That's some serious power and torque! Remember, these things were 1.5 liters.

There was lots more info there, but that's all I remember with any degree of positiveness. I'm sure others have some more good stories to report. If anyone has that issue of Motor Sport, please feel free to confirm or correct my memory, but I'm pretty sure this is the straight stuff.

Considering the 500ci Top Fuel engines make 8,000HP on 50psi I can see a small-displacement motor making 1000-1500 on Nitromethane.

wasnt the turboed formula BMWs block the precurser to the E30 M3 block?

Yep - and it was also the 2002 block.

Good questions Treb, I've been looking for this information myself. It's fun watching the old turbo cars from the roll-hoop/intake(?) camera... absolutely dead down low and just exploding with power once the boost kicks in. I don't know how those tires held on at all.. wide slicks or not!

Oh -- I guess I forgot the link to the rebuilt BMW M12/13, on low boost...

http://www.gurneyflap.com/bmwturbof1engine.html

If you have access to a really good technical library, find SAE paper 89077, title "Honda formula one turbo-charged V-6 1.5L engine"

I've got a copy of the paper- really interesting read.

BTW, the fuel was not nitromethane, but high on the odd HC's like Tolulene mixed with iso-octane and n-heptante. RON was limited to 102, but MON was not limited at all, so you could play with the fuel to pass a certain test.... Honda experimented with 30%, 60%, and 84% tolulene with appropriate amounts of iso-octane and n-heptane to meet 102 RON. With 84%, they could run much more advanced spark at full boost.

This paper covered Honda's 4bar motor that made 742 kw, almost 700Nm torque.

I found a pdf of that here

I'll have to read through it after class.

Actually, reading the paper again, I see that Tolulene was used since it was very dense, and re-fuelling was banned. 84% Tolulene, 16% n-heptante made the best power for the Honda engine. At least the 2.5 bar motor.

Since nitromethane is very poor power density, I really doubt it was used.

E-

I remember reading that some of the teams and fuel companies teamed up to suspend water in the fuel to have the benefits of water injection w/out having the injection system.

"The engine went from 450 hp to 800 hp in 1000 rpm."

facts? the best era and best F1 cars ever

EvanB wrote: I found a pdf of that here I'll have to read through it after class.

Cool!

The things that jumped out at me: the 4-bar 1987 motor made ~1000hp the 2.5-bar 1988 motor made ~650hp

The fuel, mostly toluene, was heated to 80C to help atomization.

The 2.5-bar motor used a compression ratio of 9.4:1

Interesting stuff -- thanks! Matt

650 HP. Bah. There's a Supra for sale in the paper today that claims that. Lets see that Honduh drive down to the store and bring back dog food with the AC on and the stereo cranked up.

Dr. Hess wrote: 650 HP. Bah. There's a Supra for sale in the paper today that claims that. Lets see that Honduh drive down to the store and bring back dog food with the AC on and the stereo cranked up.

Soon as we see that Supra finish a race at Monza with only 150l of fuel.

With 1/2 the displacement.

I've see a dyno sheet on a 1.3L that made about 740hp. Drove the car too. From idle to 4500rpm was like driving a lawnmower. But when the boost kicked in at 4500 hold the hell on. It would bottom the rear suspension in any gear I was willing to use, and smoke the tires in anything below 4th. I wouldn't want to drive it across town, but it was a hoot for the drive I took it on. The car you ask... a 1993 Mazda RX-7. The motor lasted about 3 months.

That PDF is an insane read. Good stuff.

And I've also heard that BMW's engine made near 1500 hp from 1.5 liters. Never been backed up with a spec sheet or anything, but it's what I've heard.

http://videos.howstuffworks.com/discovery/31678-massive-engines-bmw-m10-turbocharger-video.htm

http://videos.howstuffworks.com/discovery/31679-massive-engines-bmw-turbo-power-video.htm

I heard the fuel was super thick like soupy???

I have heard that circle track boys like to use old, rusty "seasoned" blocks when building max performance engines. Something about no further core shift, more stable blocks to build up. Made me feel better about some of the ratty engines I built up.