How much power vs. displacement, 1.7-2.0 4s Options

[Gearhead1432]

How much power have people been able to get out of a stock displacment motor? Torqure and Hp?

I can recall reading about people getting 120hp from 1.7L type one motors years ago. That is on pump fuel.

With the technology available today I would think that volumetric efficiency could be pushed further than before while maintaining reliability on the street.

So is 130-160hp out of a 2.0 totaly (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

I know Porsche did it years ago with a couple diferant 2.0L motors like the 901/911 or 587 (street motors not track). However, they were radicaly diferant compared to the simple type 4. ....

-Rob

[Dave_Darling]

You could probably get about 300 HP out of a 2.0 displacement motor.

For about thirty seconds. At a cost rivalling that of your average house. On some exotic type of fuel. With huge amounts of boost. After five years of development. (At many times the cost of the average house.)

Constraints are what give you an idea of where to go. You mention pump gas--that's one good thing to know. (Regular-grade? CA-super 91 octane? The 94 you can get some places? Something else?)

Forced induction or naturally aspirated?

How long is it supposed to last?

Is cost an object? What kind of budget is available?

Is a peaky powerband OK, or do you want a fat mid-range for easy driving?

....And on and on and on. Answer these types of questions (and many others!) and you can start figuring out reasonable limits.

--DD

[alpha434]

QUOTE (Dave_Darling @ Jan 3 2006, 07:26 PM)

You could probably get about 300 HP out of a 2.0 displacement motor. For about thirty seconds. At a cost rivalling that of your average house. On some exotic type of fuel. With huge amounts of boost. After five years of development. (At many times the cost of the average house.) Constraints are what give you an idea of where to go. You mention pump gas--that's one good thing to know. (Regular-grade? CA-super 91 octane? The 94 you can get some places? Something else?) Forced induction or naturally aspirated? How long is it supposed to last? Is cost an object? What kind of budget is available? Is a peaky powerband OK, or do you want a fat mid-range for easy driving? ....And on and on and on. Answer these types of questions (and many others!) and you can start figuring out reasonable limits. --DD

Water cool the heads and add bi turbo. Maybe not three hundred, but an easy two.

[Bleyseng]

a Jake Raby kit 2270 would be in the ballpark of what you are talking about. With Nikkies and FI its already here (140-160hp) but costs $$$$$.

[alpha434]

oh yeah- and weld the heads to the cylinders and forget about pump gas. Run the compression at 18:1.

Hehe. If anything goes wrong, you can take out a whole city block.

[Gearhead1432]

Fuel; 91/92 you can get any where

Induction; FI or carbs? I hapen to be partial to the later, but modern FI is impressive

Endurance; 100K miles sound good?

Cost; less than the equivilant 901/911 (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

peaky power bands are fun... that's why I like smaller motors.

I figure that I would just spend more $$$$ on heads and none on upping the dissplacement. Piston upgrade is nessesary however. Probably JE or something like that.

Other wise the same performance could probably be had at a larger displacement with less tuning. But that would take all the fun away.

I like motors like the 302 Z-28 with two 4bbls (IMG:http://www.914world.com/bbs2/html/emoticons/drooley.gif) or old 283 MFI 'vette motor

[Gearhead1432]

QUOTE

If anything goes wrong, you can take out a whole city block.

I like your thinking. The neighbors would feek out when it started up!

[Jake Raby]

Man, it never ceases to amaze me how hard you guys make this....

Want 155 ponies??Shell out about 4500 bucks for the 2270 kit and be done with it...

[Brett W]

To hell with pump gas, drop the compression to 6.5, throw some nitro methane at it and run 45lbs of boost.

Oh sorry you wanted this engine to last more than one trip to the gas pump. Sure would be fun though.

[dmenche914]

Sure wish us folk in the San Fransisco bay area could easliy find 92 Octane. several years ago it dissappeared from near all the service stations (at least all the station i have gone too)
We recently had a big price drop in gas, we now pay closer to the national average. Had to do with the katrina thing, and the EPA waiving the special california only gas mix (with ethonal and /or MTBE), beause of gas shortages. Seems the special gas not only reduced milage, power and rotted rubber parts in older cars, it also costs more!

Hoping for more hurricanes!

[Jake Raby]

we have 93 octane at every pump, sometimes 94 and the Citgo station sells 100 octane...

Just move out of California and you can experience it too....

[Gearhead1432]

QUOTE (Jake Raby @ Jan 3 2006, 11:08 PM)

Man, it never ceases to amaze me how hard you guys make this.... Want 155 ponies??Shell out about 4500 bucks for the 2270 kit and be done with it...

Come on Jake, that would be too easy. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) (however your kit is "plan B")

I'm sure you can appreciate people who have the desire to do something a little different. "Thinking out of the box." Some people want to put Subs in their 914, others small block chevys.

So, if joe blow down the street can build a reliable 400hp 350 for his Camaro, why can't I build a 140hp 2.0 type 4? Or is my logic missplaced? (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

As for pump gas around here, you can find 91-92 at most places. There are a few places you can get 100+ race fuel.

-Rob

[lapuwali]

The key here is specific power: hp/liter.

In a two-valve engine, getting more than 70hp/liter is getting into race engine territory. The cam required to do better than this usually produces poor low-speed drivability. Four-valve engines do better, usually 80hp/liter before it gets too cammy for street use. Variable valve timing changes the picture completely, but we'll ignore that, for now.

A 70hp/liter 2.0 would indeed make 140hp. There are several street engines in this neighborhood. The Euro-tuned Alfa twincam makes 140-150hp in 2.0 street form. Even the smog-choked, low compression, very mild cammed US version did 115hp (58hp/liter). The '72-'73 911E made 165hp from a 2.4 Six, or 68hp/liter. The 911S of that year did 190hp (77hp/liter), but it's generally considered to be pretty wild for day to day street use.

The stock 2.0 Type 4 only does 48hp/liter, so there should be a lot of room for improvement here. The number Jake just threw out 155 from 2.27L is 68hp/liter, so you should (theoretically) be able to get 135hp or thereabouts from 2.0L. I suspect that since building a 155hp 2270 costs about the same as building a 135hp 2.0, that there's little point in doing the latter, unless you're operating under racing rules that limit you to 2.0 liters.

[Jake Raby]

The difference is the RPM range needed to make the power.. A 135HP 2 liter HAS to turn and make power to 7,000 RPM to make the numbers- The 2270 only needs 5,000 RPM to make 135 HP.

Tell me which one is the easiest to drive with the best torque and usable power.....

Tell me which one will last the longest.... (remember that RPM = wear)

HP is worthless unless you intend to operate at 5,252 RPM + ALL THE TIME, thats because Tq and HP cross at 5,252 RPM.

It's all about torque, once you realize HP sucks and torque rules, you'll start enjoyiong the car a lot more...

[Gearhead1432]

Hmm, maybe I'll have to re-evaluate this. I think a 6.5K red line is in order. It must be able to go on long *spirited* drives in exccess of 1000miles.

New example. It maybe a poor one considering it is a member of the 547 family, but none the less, here it is... 1966cc (2.0) 2000GS motor. 130hpDIN @ 6.2k rpm, and 131 Lbs/ft.

[Jake Raby]

It's a 4 cam with twin ignition and a full hemi chamber...

It's not even on the same planet as the engine's we are discussing here and it was designed for a 1200 pound aluminum bodied car.

I have driven one in a 59 Carrera GT and the powerband was worthless, slow as dirt..
here she is, this car raced at Leman in 1960 piloted by Bill Romig- yes those are aluminum brake drums...

This engine made 138HP as a 1600, Abarth tuned..
(IMG:http://www.aircooledtechnology.com/pics/carrera/DSCN0022.JPG)

[Gearhead1432]

That's a great looking speedster. (IMG:http://www.914world.com/bbs2/html/emoticons/drooley.gif)

But you said it's a 1600, that must be a 547 or other earlier motor, I was refering to the 587 2000GS motor found in the Carrera2. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

It looks like 110 hp at 3.5Krpm is easy to make. And that is with out a real header and with 40mm carbs.

So add better heads with cam... maybe 44IDFs or some kind of FI... tangerine header....

It looks like another 25hp can be found in there.

[Brew]

QUOTE (Jake Raby @ Jan 4 2006, 05:06 PM)

HP is worthless unless you intend to operate at 5,252 RPM + ALL THE TIME, thats because Tq and HP cross at 5,252 RPM.

Jake, I understand and agree with your post, except for this quote. Obviously, just because Hp and TQ cross at 5252 doesnt mean that's where either of them necessarily peak.

Or am I reading it wrong?

[Jake Raby]

Nope, the peak is dictated by the overall engine combo.

The fact is that below 5,252 RPM Torque is always higher than HP.

Above 5,252 RPM HP is always higher than torque..

So HP is not huge unless your engine is very much still revving and making power past 6K.

Dyno graphs that don't cross HP and torque at 5,252 RPM are not accurate- the formula is incorrect.

Here is an example of a correct dyno graph
(IMG:http://www.aircooledtechnology.com/type4/914/2270_performer.jpg)

[Brew]

Ok, I get ya now. Thanks!