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I did it the old fashioned way. I went with forced induction. All you youngsters, should probably go Nitrous Oxide. It's way cheaper, it fits, and it works.
I have no idea of the cross sectional runner size of either manifold....however, the AM manifold appears to have ample runner cross section, from the pictures.
Draw a diagram of how the air has to flow through Carl's intake, in order to get to the intake valves. Now draw a diagram of how the air has to flow through the AM intake, in order to get to the intake valves. Note that the air through an AM manifold has one less 180 degree bend to make.....that's going to be a significant difference.
Measure the intake runner length of the AM manifold and compare that to the runner length of Carl's intake. 1.5 times as long? Twice as long?
Cross sectional runner size being equal, the AM manifold should make considerably more torque....everywhere. There might be a small loss in horsepower on the very top end compared to Carl's intake, because of the longer runners.
How you are going to get either intake under a hood is beyond me.
I was thinking along those lines too. one of the things that should also be a benefit, is the bell mouthed inlets. those are amazingly more efficient for flow, as you have probably seen on a flow bench. as you say, if it makes more HP all the way up to 6,000rpm and loses from 6-6.5Krpm, then the AM V8 intake would be more effective overall.
As far as fit, forward mount is pictured as i have about 1.5" clearance over the cross bar, (for the hood to close) but that goes to 0 as you go forward unless the intake has a tilt to it. I'm sure i can do that too, but its a little sketchy. i have to mock up something. however, rear mounting is a pretty straight forward fit. BUT, the surface of where the TB will mount is at the firewall. you tell me, is there room rear ward to put the TB, MAF and a 90degree elbow with a filter? I suppose there is room for a TB, and elbow and then mount a MAF and a cone filter going to the side ... that's the configuration that looks to be the easiest fit.
Originally Posted by polecat702
I did it the old fashioned way. I went with forced induction. All you youngsters, should probably go Nitrous Oxide. It's way cheaper, it fits, and it works.
Ive already raced with a NOS system for a couple of years with the 928. it was fun... bought 50hp on the straights with a dead pedal activation button. lasted for almost an entire race, with a 10lb bottle fill.
ask carl to make you one of his intakes with ~1.875" ID or even 1.75" runners instead of whatever was used for the 6.5L.
youll need to get the "R3" cams that were used on the 6.5 dyno engine to make it work.
I was thinking along those lines too. one of the things that should also be a benefit, is the bell mouthed inlets. those are amazingly more efficient for flow, as you have probably seen on a flow bench. as you say, if it makes more HP all the way up to 6,000rpm and loses from 6-6.5Krpm, then the AM V8 intake would be more effective overall.
Yup, I spent almost 20 years racing air cooled 911's, personally. And I made the same mistake for years, before figuring it all out....never trade midrange torque for high rpm horsepower.....even if you have short gear ratios to be able to use the higher rpms. All you end up doing is beating parts to death, while not going any faster on the track. Whoever said "Torque wins races, horsepower sells engines" nailed it.
As far as fit, forward mount is pictured as i have about 1.5" clearance over the cross bar, (for the hood to close) but that goes to 0 as you go forward unless the intake has a tilt to it. I'm sure i can do that too, but its a little sketchy. i have to mock up something. however, rear mounting is a pretty straight forward fit. BUT, the surface of where the TB will mount is at the firewall. you tell me, is there room rear ward to put the TB, MAF and a 90degree elbow with a filter? I suppose there is room for a TB, and elbow and then mount a MAF and a cone filter going to the side ... that's the configuration that looks to be the easiest fit.
I would not fight this.. Mount if forward, cut a hole in the hood. Mount a throttle body and some sort of cone air filter. Use a Alpha N injection upgrade from John Speake to get rid of the MAF and still keep the simple tuneability, reliability, and simple parts of the stock injection system. The coldest air at the track will blow right down the throat of that intake. I'm not sure it can get any better than that!
Ive already raced with a NOS system for a couple of years with the 928. it was fun... bought 50hp on the straights with a dead pedal activation button. lasted for almost an entire race, with a 10lb bottle fill.
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
Whoever said "Torque wins races, horsepower sells engines" nailed it
Is that why the 2007 BMW F1 cars were so slow?
It's about 740bhp, and a pretty tiny 230lb/ft of torque.
So 6lb/ft less than a Golf TDI. And with about 150lb/ft at 6500rpm, it's got about the same torque at that RPM as an EP Civic Type-R, which frankly, isn't a whole lot- People make fun of Type-Rs for being torqueless, but F1 engines are no better.
Imagine you had a car with BIG bhp, but a tiny peaky powerband, and a gearbox without close ratios. So every time you changed up a gear, you dropped out the powerband, killing your acceleration. So despite the big peak power number, a lesser tuned car, which was less peaky so didn't drop out the powerband, and no doubt had more low/mid torque, would actually be faster; especially on tighter tracks.
In the old days, where this quote seems to originate from, this would be even more of an issue, especially with heavy "muscle" cars running 4, 3, or even 2 speed gearboxes, which means powerful but peaky cars would easily drop out the powerband and be **** slow compared to torquey but low power cars.
But these days, where you tend to have to either totally f*ck up the spec to make it mega peaky, and even peaky engines have closely spaced 5/6/7/8 speed gearboxes, the likely hood of even a road car being driven properly falling out the powerband is slim, and literally no chance on a well built race car.
That's my theory anyhow- This quote is out-dated and taken out of context.
Anyhow, this quote, almost always used by butthurt turbo diesel owners, low power V6 and V8 owners, and anyone arguing with a Honda owners, just makes people who are trying to be clever just sound clueless, like they've never had a proper race or even driven a performance car in their lives. I mean seriously? One tear up with a lower torque but higher power car would tell them their argument is pretty retarded.
When most people talk about torque, what they really mean is low/midrange grunt, and while it's great (I LOVE torque, it makes cars much more fun to drive, in fact it's why I love big boost turbo engines), and it's certainly something any performance engine, road or race, should aim for the maximum of, providing they've got the traction to make use of it, it's not what wins races, power is.
BHP is just Torque and Revs combined. It's a tricky one to explain in words, it's far easier to experience in reality by driving various cars, but torque is the "Strength" of your engine at a set rpm, but the faster your engine is spinning the bigger effect torque has on performance, so torque+rpm = POWER, which is key to how fast your engine can accelerate (providing it can stay in the powerband though the gears, that is!).
Next up, a standard BMW 335D, 3ltr twin turbo diesel engine...
The above dyno is at the wheels, so I'm going to add about 30bhp/30lbft to these numbers, which about tallies up with the official 282bhp and 428lb/ft figures.
Either way, say peak torque is 428lb/ft, that's 200lb/ft more than a Formula f*cking One engine. And a remapped one is something upwards of 500lb/ft if I remember right, over DOUBLE what one of the modern V8 era F1 engines were.
Does that mean Formula 1 teams are stupid and they should've just used a 335D engine with a £150 plug in remap and be ****loads faster? **** no, as only retards think that.
Even comparing like for like cars, 335i vs 335d, and the 335i is plenty faster, despite "Only" having 20bhp more than the diesel, and about 130lb/ft LESS. Basically, it's not true.
Every "Torque wins races" person says next... "But, but, but, WRC cars only have 300bhp but like 700lbt/ft, and they're mega fast, they win races" YES, but they've not got '300bhp' by choice- That's all they can manage because the rules dictated an inlet restrictor to prevent power going higher.
With no option of more power, no issues with traction due to 4wd and sticky tyres, AND a style of motorsport that involves a lot of very slow corners where instant momentary punch of acceleration is a big advantage, you'd be out of your mind not to go for maximum torque to go with the limited bhp you're stuck with.
But for next year the rules in WRC are changing once again, inlet restrictors bigger than ever, allowing more than 400bhp if I remember right. So will they still go for maximum possible power, if it's "Torque that wins races"? Yes they will, as it's power that's the no1 performance enhancer.
Another argument by these people are "So, if torque isn't important, why do drag cars run big V8s?". Err, mostly as they're the easiest to get POWER from you clowns. The above car is Larry Larson's S10 10ltr twin turbo V8 pickup truck. Yeah it's got ****ing ****loads of torque, but the reason it runs 5sec quarters at over 240mph is because the bloody thing has upwards of 3000bhp!
Torque is a BAD thing for him, and because of this he deliberately launches at just 8psi of boost, as at full boost it'd make so much torque it'd just smoke the tyres. In fact it's only ramped up to full boost (50psi!) by most the way down the track and he's already doing over 180mph! "Low RPM V8 Grunt" is literally no issue on fast drag cars either- Larry's car never sees under 8000rpm for the whole run after 1st gear!
So once again, power wins races, and in fact, torque can slow you down if you've got more than your tyres can handle...
Why do so many really, really, fast drag cars run centrifugal superchargers, despite turbos giving far more power, and positive displacement superchargers give far more torque? Because turbos and positive displacement superchargers give TOO MUCH torque for the grip, meaning too much wheelspin for any given power level, making them slower overall. Centrifugal chargers increase boost linearly with rpm, giving LOTS of power, almost as much as turbos, but adding only a little extra torque, especially at low and midrange rpm, so they are FAST due to the big power, but still don't wheelspin due to the lower torque.
It's the same reason a lot of the fastest FWD track cars run centrifugal chargers too- FWD is grip limited, and they need big power to "win races", but don't want too much torque or it overpowers the tyres, and thanks to the power delivery of the centrifugal charger they can use more throttle more of the time without it being wasted in wheelspin.
It's the same reason many production turbo cars, and most the fastest turbo race cars, run lower boost in lower gears and lower rpm, compared to in higher revs and rpm- To limit torque so they've got more traction, making them far faster overall.
It's also why naturally aspirated 2wd rally cars are often as fast, or faster, than the 4wd turbo rally cars, on grippy dry tarmac surfaces (where 4wd was no advantage), despite having the same power and often well over 400lb/ft LESS torque- Because its POWER that's the number one performance enhancer, not torque. This happened a lot in the late 90s, with the 4wd turbo WRC cars vs the N/A FWD F2 Maxi Kit cars..."So, is torque totally pointless then or what???"**** no! Torque is awesome! Generally, I ****ing hate cars with no torque! Surely, if you've any experience of driving at all, you know torque is great, but despite all this, it's not the key need for pure performance.
Low/midrange torque makes for a nicer, easier, car to drive, especially in slow/fast/slow/fast/slow driving, saving you constantly rowing the gearbox to stay at high rpm where the power is. It's why things like Type-R Hondas need driving hard and dropping gears constantly to be fast, and a Golf TDI just needs the throttle planting in almost any gear to go fast- But ultimately, the Honda, with more power, despite loads less torque, is the fastest if both are driven on the limit.
I drive like a dick and love drifting, so LOTS of torque to smoke the tyres is great for me too. I actually find a lot of drift car setups bizarre, as they ideally want torque but the engine isn't tuned/specced for it.
And regardless of drifting, I like BIG boost, as boost = torque, and torque = fun to drive, BUT if I wanted to go as fast as possible, while I'd want the MOST torque my tyres could handle- I'd not want more than that, as it'd be pointless.
So overall..
TORQUE = GOOD.
TORQUE IF YOU GOT THE GRIP FOR IT = FAST
BUT FAST? = POWERRRRRRRR
About 10 years ago I was helping organize the Corvette Racing Reunion party at Elkhart Lake. In attendance were people like Dick Thompson and John Fitch (was quite the honor to meet and speak with him).
Anyway.....some other driver who's name escapes me, multiple SCCA champion in various Corvette's in the 60's. He made quit a name for himself when he stuck with small blocks when everyone else went big displacement. He said at least 10 times during this speech / story telling: "Torque breaks parts - I won so much because I finished".
I think it looks surprisingly complete. just now question the plumbing rearward, Are there costs available yet for the Carl 654 intake?
as far as the AM intake goes, im pretty confident based on measurements, it will fit . the only mods i need to make are to the oil filler. (not that difficult but carls doesnt need to make that mod). and, with the location of the TB in the near stock location, refitting the stock throttle linkage would be easier as well.
oil filler...i fill mine through the cam covers! minor issue...just have a small funnel handy
what about a "bulge" to the hood to accommodate it?
It's about 740bhp, and a pretty tiny 230lb/ft of torque.
...
So max torque around 16,000 rpm... Put it in a black box with a 3:1 gear reduction and you've got 690 lb/ft at around 5000 and 740 bhp at 6000, right?
More RPM's is never a bad thing...
It's about 740bhp, and a pretty tiny 230lb/ft of torque.
So 6lb/ft less than a Golf TDI. And with about 150lb/ft at 6500rpm, it's got about the same torque at that RPM as an EP Civic Type-R, which frankly, isn't a whole lot- People make fun of Type-Rs for being torqueless, but F1 engines are no better.
About 10 years ago I was helping organize the Corvette Racing Reunion party at Elkhart Lake. In attendance were people like Dick Thompson and John Fitch (was quite the honor to meet and speak with him).
Anyway.....some other driver who's name escapes me, multiple SCCA champion in various Corvette's in the 60's. He made quit a name for himself when he stuck with small blocks when everyone else went big displacement. He said at least 10 times during this speech / story telling: "Torque breaks parts - I won so much because I finished".
Dead nuts correct right there! Ill explain why greg makes the mistake below, as many do. On one hand he is half right, but talking two different languages in a way. (and so is anyone that talks about HP and torque in the same breath) it boils down to HP , at any speed , determining acceleration potential. low RPM or high RPM, if you have more power, you will out accelerate any competitor. another great example...... the viper vs the GT3RS. both with the same HP, they accelerate the same, EVERYWHERE. why, even with the peaky hp curve , it stays at or near max Hp as much as the viper with wider gears, (and all that torque...which just broadens the HP curve) because of its close ratio gears. in the end, its just HP.
Originally Posted by GregBBRD
Notes above, in blue.
Greg, you are part right. explaining it without misinterpretation is the key here. when you or someone says, broad torque curve, anyone in-the- know will just tune out. it's average HP you look to maximize over a lap. The gears are just HP optimizers. the more peaky the HP curve, the closer the gears need to be. There are many big "torque" engines that still have a 'peaky" hp curve. BUT, to your point, with a lot of torque, traditionally, this will mean that the hp curve will be broader. meaning.... You have more hp than a competitor with the same peak hp , down at the lower RPM.
however, this doest mean you are allowed to short shift or spend more time at the lower RPM range. when racing, you need to always be in the peak HP range. with our cars, this means 4500rpm to 6500rpm. when I got 100 more lb-ft of torque with the stroker, i thought i could run as fast by short shifting.... i was a second slower! i had to drive the engine the same to get the gains. the torque peak was irrelevant, but the 50hp gain from 4500 to 6500rpm was what made the car faster.
so, no , torque does not win races. its power and more specifically, its average power available. BUT, to your point yes, its better to make more HP in the lower RPM range than it is to have less HP down at the lower RPM range. is it better to have more Hp down low than up top? sometimes.. ONLY when the average is better.
example: I raced a S2000 at Infinion when i got the stroker installed (first race) he had 420rwhp and i had 370rwhp. The S2000 was a turbo and was VERY peaky. his average was 320rwhp over any two gears... where i was 350rwhp average between any two gears. this was the difference. I know you know this intuitively, but its all about Average HP through the gears.
So max torque around 16,000 rpm... Put it in a black box with a 3:1 gear reduction and you've got 690 lb/ft at around 5000 and 740 bhp at 6000, right?
More RPM's is never a bad thing...
It think the point is, peak torque is meaningless, especially in high RPM engines. if you see the HP of this Ferrari below, this car would never be driven anywhere its torque peak.
I don't get it either, I covered many miles in my fathers 355GTS, one of the most torque-less V8 cars in history. Time to pass someone in a hurry, drop it into 2nd if between 55-60mph, shift at 8,500 and enjoy the noise.
If memory serves, they do not put down much more than 200ft-lbs at the rear wheels and usually close to 300rwhp. Based on the torque numbers alone, as that article discusses, a TDI VW would keep up with one.
Friend of mine has over 50k miles on his 355, tracks it multiple times a year. I don't think he's ever below 6,000rpm.
People who complain the 355 is slow due to lack of torque must have broken transmissions and are stuck in 5th.
To shorten the runners in the A-M manifold (to shorten them/ raise peak torque RPM, and to shorten them/fit the whole ting under the hood... Um, just shorten the lower ends of the runners. You planned to cut them and match them with the Hans mating flange and nozzles, right? Cut them short enough to raise the peak torque RPM and get the while thing under the hood.
Don't be afraid to go with a modern engine management system. That lets you do a lot of adjusting and datalogging, light-years beyond watching the AFR lights. At least put in the correct wiring harness for the later Porsche controllers so you can Sharktune. You've only managed to see a fraction of the available power with the engine hardware you have as you rely on changing fuel pressure to control everything. Buy the wiring harnesses from Mark during the half-price sale...
It think the point is, peak torque is meaningless, especially in high RPM engines. if you see the HP of this Ferrari below, this car would never be driven anywhere its torque peak.
Nonsense. Plot wheel torque against wheel RPM in each gear, that will tell the story.
11-28-2017, 09:28 PM
- Ok, not really.....
