Superchargers In Sportscars -- The Sequel

[Tim Northcutt]

I looked for this thread that was running a few weeks ago, and apparently it has been cleared to make room for new topics, etc....

That's OK...I understand....

On this thread about using superchargers in sportscar racing, a number of issues were raised about good sides and bad, especially when compared to using a turbo...

I raised the issue of possibly "Cherry Picking" a few courses in the ALMS Series, such as Sonoma, the Miami street circuit, other possible steet circuits, the Washington DC race (if it comes back next year), and possibly even Trois Rivieres and/or Mosport to run a Whipple Lysholm-type twin-screw supercharger on an engine like the Northstar for these circuits....tracks where top end is not necessarily at a premium, but getting the power & torque out of the corners would be...

Some liked the idea of "Cherry Picking" in this way with a "Blower Caddy" and buying the Team Cadillac cars to do it....

The plan would be to run the turbo at Sebring, Road America, Atlanta, etc., but use the supercharger on these short tracks to get the horsepower without suffering from turbo lag...

I e-mailed Whipple's technical dept. for their input and included many of the downsides expressed by all of you, and this was their response:

"You are right the supercharger will give you the torque for out of the corners , I am not sure it would be the best for max horsepower at places where there were long straights, but the horsepower would still be strong. On a short track I feel it would outperform the turbo cause of no lag. We have not worked with the Northstar motor in any projects . You would definitely want to use an intercooler on it. I do not feel belt slippage would be an issue...we have up to 12 rib pulleys on the shelf that we run on 1400 HP motors with dual superchargers. I know this is an brief answer but I hope it will help you."

Sounds very positive to me....or at least worth experimenting with to see if it would be effective....

Time to buy that Powerball ticket.....I can see that "Blower Caddy" running, and possibly winning, a future ALMS event or two at Sonoma, Miami, DC, or wherever...the MG-Lola showed that the Audis can be beaten on courses where their horsepower and top end speed are negated by the characteristics of the circuit...

After all, the goal under the new system will be season points in either the ALMS or the LMES to get the automatic bids to Le Mans, and the four circuits in the LMES would not lend themselves to this "Cherry Picking" idea.

Your thoughts?????

[gttouring]

As you know I couldn't resist to chime in
Sounds as if this is a proper way to go, and rember that this top end power idea is relative, even if a super charger was used on longer tracks, could not the engine be tuned to reach peak HP at whatever RPM and run with it? thus negating the turbo advantage... so if both are dynoed a turbo Northstar and a SuperNorthstar and they put out 650 hp at 8500rpm would it matter what motivates the power?
and you see that the torque figures at the lower end 1K to about 3K fall to the supercharger's advantage. this i think is an idea overlooked by many and I couldnot convey in "Part 1"- this could keep it cheap as we wouldn't really have to cherry pick-trouble is the fuel mapping for the SuperN- as the fuel load would be big both down low and up high in the Rpm Range, so is the economy issue goona be trouble? and what about weight savings of a SuperNorthStar vs. the TwinTurboNorthstar?
both can be used but even if the engines were tuned for 800 hp we could get it to work the good old boulevard way with a blower- and a hot rod caddy is not a bad idea for GM or a race car.

[gttouring]

well this has been ill recieved hasn't it
another thought-
a 4.0litre twin turbo V8 (VAG)
and the 6.0litre NA (RYR) V8
isn't the power potnetial for the TT just much much greater?
easily 1 turbo on a 6 cylinder can out power the 6litre motor,
I know they use boost control to regulate the power but does it really? Sure the Yates V8's haven't really been far off, but they are distant 2nd to all the turboed VAG plants.
As reliability is an issue over 24 hours the revs being equal, how did the yates motor expect to really out power the VAG turbos? or were they equal and aero effects hampered the panoz and the Amerisuites LMP900? (what is that anyway? a Dallara?)
If 1 3.0litre V10 can rev to 19K ala ferrari and rarely blowup why would the Yate V8 not attempt to raise the bar to about 10k versus the 8k they run now in an effort to out power the turbo?, and if it isn't possible you wonder why evryone doesn't use turbos

[flatlander_48]

Remember the compound supercharged Lancia Stratos rallye car? It used a supercharger for low end torque AND a turbo for high end horsepower for the best of both worlds. The problem (and downfall) was a complex switching mechanism.

[NSMG]

Originally posted by flatlander_48
Remember the compound supercharged Lancia Stratos rallye car? It used a supercharger for low end torque AND a turbo for high end horsepower for the best of both worlds. The problem (and downfall) was a complex switching mechanism.

The lancia that featured the turbo + volumex supercharger wasn't the stratos, it was the fabulous Gr.B Lancia Delta S4.This engine had unlimited potential...in the words of Ing.Lombardi (who designed it) :''it is basically an F1 engine!''.

Best Regards.
NSMG

[flatlander_48]

Thanks for the correction. As far as I know, no one else has put together a similar arrangement. Given subsequent advances in electronics and materials science, I wonder if the idea would fare better today?

[Andy Zarse]

Originally posted by flatlander_48
Thanks for the correction. As far as I know, no one else has put together a similar arrangement. Given subsequent advances in electronics and materials science, I wonder if the idea would fare better today?

I watched this Lancia thing on it's international debut on the Lombard RAC rally in 1984 or 85, I can't remember which year, as it's too long ago! But it was an amazing bit of kit. I was working as a start marshall on a stage in North Wales and when I sent it away, I remember it was visibly quicker than the Quattros, Peugeots etc. That was the benefit of the supercharger I guess, grunt and torque. Oh, and it came first and second, Tony Pond was third in the MG Metro. Not bad for a debut. The fact it was so fast ultimately must be down to turbocharging.

Markku Alen put it round Estoril in a test for the Portugese Rally with the boost wound right up. His time would have put him on the second to back row of the grid for the previous years F1 Grand Prix!

Superchargers are great for road cars, especially the twin screw type, and better than turbos for this purpose. IMO the Roots type blower should have been dropped at the end of WW2! But if you want to win a race, turbo is by far the better bet, for reasons most eloquently made in this and other posts. Witness the MG Lola the other day!

[flatlander_48]

F-1 started coming to Detroit during the turbo era. It was amazing to hear the difference in exhaust note between the turbos and non-turbos. What it says to me is that there is a tremendous amount of unused energy that goes out the exhaust of a non-turbo engine. It's not "free" of course, but what there is can certainly be put to good use.

In terms of weight, I would guess that blower and turbo systems are fairly close. A blower casing and rotors would likely be heavier than a turbo, but my guess is that the disadvantage would be offset by extra exhaust plumbing and waste gates for the turbo. What I am getting is that the weight of the system probably doesn't have a lot to do with the choice. Thoughts?

[cybersdorf]

Originally posted by NSMG
The lancia that featured the turbo + volumex supercharger wasn't the stratos, it was the fabulous Gr.B Lancia Delta S4.

Let's not forget its predecessor, the supercharged 037.

[cybersdorf]

Some tech bumph on the 037 supercharger here:
http://digilander.libero.it/lanciara...aletecnica.htm

The engine for the 037 was tested at Le Mans in the Abarth 035:

[noise boy 2]

Originally posted by flatlander_48
F-1 started coming to Detroit during the turbo era. It was amazing to hear the difference in exhaust note between the turbos and non-turbos. What it says to me is that there is a tremendous amount of unused energy that goes out the exhaust of a non-turbo engine. It's not "free" of course, but what there is can certainly be put to good use.

In terms of weight, I would guess that blower and turbo systems are fairly close. A blower casing and rotors would likely be heavier than a turbo, but my guess is that the disadvantage would be offset by extra exhaust plumbing and waste gates for the turbo. What I am getting is that the weight of the system probably doesn't have a lot to do with the choice. Thoughts?

I would have to agree that weight would not be the big issue with either system. The combined weight of the turbo hardware (including the extra piping for the exhaust) would probably equal out to the weight of the typical twin screw supercharger. I think that what hurts the twin screw supercharger, is that it requires a manifold with fairly short intake runners as it sits on top of the engine in a V type engine configuration. The other issue is the parasitic loss of having to drive the supercharger off the crank. The turbo allows for a much better opportunity to tune the runner length to projected powerband of the engine.

As far as the sound part goes. It is correct that the turbo engine will be quieter than the N/A or supercharged motor, but the reason is not so much that the power is being lost out the tailpipe as that the turbo acts as a restriction in the exhaust system (much like a muffler) which causes the exhaust pulses to be evened out thus lowering the sound output of the motor. Robert

[noise boy 2]

Originally posted by gttouring
well this has been ill recieved hasn't it
another thought-
a 4.0litre twin turbo V8 (VAG)
and the 6.0litre NA (RYR) V8
isn't the power potnetial for the TT just much much greater?
easily 1 turbo on a 6 cylinder can out power the 6litre motor,
I know they use boost control to regulate the power but does it really? Sure the Yates V8's haven't really been far off, but they are distant 2nd to all the turboed VAG plants.
As reliability is an issue over 24 hours the revs being equal, how did the yates motor expect to really out power the VAG turbos? or were they equal and aero effects hampered the panoz and the Amerisuites LMP900? (what is that anyway? a Dallara?)
If 1 3.0litre V10 can rev to 19K ala ferrari and rarely blowup why would the Yate V8 not attempt to raise the bar to about 10k versus the 8k they run now in an effort to out power the turbo?, and if it isn't possible you wonder why evryone doesn't use turbos

There is a second regulatory action in the rules for the ACO. The engine is required to breathe trough a restrictor which also helps to equalize the outputs of the various powerplants. This is also why none of the engines in sportscars rev to the moon ala f-1 or cart, as at a certain point the engine cannot get enough air in to sustain the rpm. A 6 liter motor requires 6 liters of air for every revolution (plus a relatively small amount of gas) to operate. At a certain rpm the two 33.1 mm holes that the engine has to breath through will not allow enough air to pass to continue revving witout going hyper rich and killing the power anyhow. Robert

[flatlander_48]

Without a restrictor plate, Winston Cup engines will run up to 9,000 to 9,500rpm depending on track configuration and race length. The problem is the pushrod valve train. It won't live for 3 to 4 hours at higher speeds. When restrictor plates are added, the engines only rev to about 7,500. As noise boy said, you just can't pass enough air.

Also, remember that F-1 engines use pneumatic valve springs. That is why they can buzz up to 19,000 and run for 2 hours. That and much smaller and lighter pistons, rods, crank, etc. than you would have for a 5.7L V-8.

[Kurt Maxwell]

Are superchargers legal in the FIA GT?

[KA]

Haven't bothered to look it up, but I'd guess yes, so long as your basic production car is supercharged- Turbocharged cars are still allowed AFAIK (there have certainly been one or two Porsches out in GT this year, including Proton's old 911GT2), so I can't see how they'd take a different position on supercharging-

Is anyone (other than Jaguar- now there's a thought... ) currently building supercharged production cars that would be eligible for GT?

[Tim Northcutt]

Isn't Mercedes building production cars with superchargers?

The MG X-Power SV (a great-looking sports roadster) also has a supercharged version of a V-8 that they not only build, but also will configure for racing straight from the factory, according to the mg-rover website (I haven't looked up this car in a few months, but it was on the "Development Zone" portion of the mg-rover site....

[Tim Northcutt]

A Few Notes:

The Lancia combined turbo & blower is interesting, but the more complicated systems are made, the more likely they are to develop problems or to fail....even with electronics & computerized mapping, I would prefer to go a simpler route....
To Noise Boy 2:
I agree with a lot of what you have written, but....
The twin screw Lysholm type system suffers very little parasitic drag...it was origianlly created as an industrial air compressor, and Whipple has mapped them to produce plenty of power to overcome this in the lower rpm ranges.....at least that is what they have told me when I've asked them that very question in the past....

On GTtouring's original comment: I understand where you're coming from and I agree except for one point point... the twin screw system has a strong, but fairly consistent power delivery throughout the rpm range, but if you look at the charts on Whipple's site, their power flat-lines in the highest rpm range, and that is where the turbo would have a slight advantage on the top end....and thus on the courses with longer straights where horsepower is at a premium....

Thus I would still look at "Cherry-Picking" my tracks where I ran the "BlowerCaddy" and my list would include Sonoma, Laguna Seca, street circuits like Miami, Trois-Rivieres, D.C. (if it ever comes back) and also Mid-OHIO when it returns to ALMS for the 2004-2006 seasons....the back straight at Mid-Ohio might be a potential problem against a turbo for top end, but in the tighter sections that make up virtually 2/3 or the circuit, the "BlowerCaddy" would have a distinct advantage....

[Tim Northcutt]

BTW..the AmeriSuites car is an R&S chassis with the Lincoln engine, not the Yates...their power is built by the Lozano Bros. (I believe that is the spelling of their name)

[flatlander_48]

Originally posted by Tim Northcutt
Isn't Mercedes building production cars with superchargers?

Yes, the ones that say "KOMPRESSOR"

Cybersdorf:
Sure wish my 131 (r.i.p.) had looked like that!!

Yes, the Lozano Bros. is correct. They also used to build the Fords that Dyson ran in his R&S's.

[gttouring]

they did a much better job for dyson
hmm

[avsfan733]

Garett had a technology a few years ago which was basically a turbocharger run off of hydraulic pumps on the engine as opposed to exhaus tgas, I wonder what ever happened to the technology after they tossed it on the scrap heap and the patent reverted to the designer?

[Tim Northcutt]

A few months back, I started a thread about the "Lincoln Engine" based on some basic info I got from AmeriSuites that said the Lincoln engine is basically the same ford 6.0 L engine that can, and has been, badged as a Lincoln...

When I questioned why the builder (Lozano Bros.) wasn't getting the same results as Elan or Yates for power, etc., someone from the team who reads this forum said (and I paraphrase) that they started their operation shortly after the first of the year, and that the Lozano Bros. were a little behind the curve in adjusting the engine to the 2003 restrictors for Sebring, but power is a secondary issue...the builder is a good one, and that will be sorted out...

he first order of business for the team is to get better acquainted with the R&S chassis, because both drivers are from Trans-Am and running a high-downforce prototype is a whole new challenge for them (hence the spin at Atlanta early in the race)....

They are getting a better feel for what the car will do and how to tweak it before dealing with the power issue....

[gttouring]

a supercharger racer in todays races (GA and speed gt) is the Steeda Q400, a 4.6 litre sohc Vortech type supercharged Mustang-er Q400.
It pump out 450+ HP and it races, haven't seen it too much though, and of course as mentioned the roots type blower on the Acura NSX of real time racing. which won on a few occaisions and got Ballasted to be equal and then blower pulley (boost) reduced.
So blowers work on many types of races, perhaps you can tune it to a NA type perfection. which i see as a chance to over come restrictor sizes. If a 4.0 can be turboed, a natural 4.0 would have of course bigger restrictors building the motor as the natural 4.0 and making it produce power to compete, then placing the restrictor on and then applying the supercharger might make it a very potent powerplant, we can expect it to have better power and results than the Elan or the Zytek for sure, and if a lowboost mustang(the article in 5.0 magazine said it was at 8psi boost with stock crank) can make 450+hp a 4.0 litre V8 with proper racey parts can easily reach the 6.0 litre panoz level and possibly wrangle with the VAG plants.
high RPMs be damned, if it revs to 7K and pushes out 700HP who cares?

[Tim Northcutt]

Unless someone tries it, we'll never know until I hit the Powerball jackpot...but it sure does make sense to me...

It would take a decent amont of testing to sort it out...so for now, I'll stick with my original tighter tracks with shorter straights...

Another one to possibly add, since the race will have so much at stake would be the LM 1000 km. this November on the Bugatti Circuit...

I watched the 24heures Moto GP on Speed Channel, and most of that circuit is tight and winding...a definite possibility for the "BlowerCaddy" or any other supercharged engine..

[gttouring]

you are correct Sir!
that just gave me an Idea for tuning my car in a game for the bugatti circuit, i got kinda xcited- when all else in life is failing at least a game has a reset button.