Cost of mods per hp- need your #s

[carnut169]

Thought this would be interesting...


SSI's- $1100 20hp $55.00 per hp

Autothority's Mass Flow Kit- $1800 38hp $47.37 per hp

Chip- $300 16hp $18.75 per hp

Supercharger:

Whipple (low) $7400 126hp $58.73 per hp

Whipple (high)$ $12,500 206hp $60.68 per hp

Paxton $4900 126hp $38.89 per hp




Looking into cams, turbo kits, V8 kits, other exhaust options.... I'll do a spread-sheet if you guys help w/ some of the numbers. I am also doing this for a 3.2- might be interesting to do a sheet w/ info for 3.0's, 2.7's etc.





------------------
87 Carrera Cabriolet

[island911]

Good idea. This is something that gets done and redone. . .may as well pool the knowlege.
The tough part is knowing the the total cost of an add-on. When you start talking supercharging, there is the additional cost of replacing the weakest loaded links . . . the 915 comes to mind.
The implementation costs/hp are good to know though. I especially like add-ons that lower entropy, such as SSI's, higher compression and such.

---

'81 Platinum Metalic SC COUPE

[RarlyL8]

Better keep this list strictly 911 engine related. Small block Chevys run around $8/hp, proper installation and kit would probably only double or tripple that figure at best.

Here's one:

Used stock 930 - $6500 @ 265hp = $24.5/hp
SS Exhaust and Muffler - $3500 @ 300hp (-265) = 35hp = $100/hp
K27, intercooler, 1bar spring - $2650 @ 350hp (-300) = 50hp = $53/hp

TOTAL - $12650 @ 350hp = $36/hp


[This message has been edited by RarlyL8 (edited 08-15-2001).]

[RarlyL8]

Here's a good one:

K&N PowerCharger for 930 - $400, hp - maybe 1 = $400/hp

HAHAHAHAHAHAHAHAHAHAHA!!!

[Early_S_Man]

How are you going to figure the snakeoil category that actually 'cost' hp?

The K&N filters for CIS, and the Zucker air boxes for Carrera 3.2 & 964 come to mind, where Bruce Anderson has reported power losses on the dyno, typically 1-3 hp!

------------------
Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[carnut169]

The other interesting thing is the whole weight-hp ratio. I was watching "Junkyard Wars" (show on TLC where two teams are assigned an item to build- rockets, race-cars, demo machines, whatever- but it has to be built out of stuff they find in the junkyard) and the assignment was dragsters. One of the teams used a v8, and a heavy set-up, the other used a very light frame and it was powered w/ a motorcycle engine. I don't know who won- (I fell asleep) but the interesting thing was something they said about weight and hp....


Again, I was sleepy, but they said something like for every 4lbs added, the engine needed another hp to maintain the same 0-60 times. If you use the formula for computing hp (The formula is: hp = weight * (speed / 234)3 ) This method uses the weight of the car and the speed at which the car completed the quarter-mile run. If you don't want to do the math this link will do it for you!

http://www.dsm.org/tools/calchp.htm


So anyway, the least expensive way to add hp would be to eliminate weight... 1 hp for every 4 lbs. Take out the spare tire and add a can of fix a flat, etc.


Also, if all that is true, then a gallon of gas is 5.8 to 6.5 lbs per gallon. Our tanks are aprox 20 gallons which translates to a 30hp difference between a full and empty tank!


------------------
87 Carrera Cabriolet

[Clark Griswald]

Need to be carefull about vendor claimed hp and real world.

MAF for example gives nowhere near 38 hp. According to B. Anderson, it's good for about 7 hp.

And I would like to see the elusive 16 hp chip.

[wckrause]

I think I'm going on to go on a 10hp diet.

Is my beer gut considered sprung or unsprung weight????

------------------
Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

[Bill Verburg]

IF it bounces its sprung, if not unsprung.

------------------
Bill Verburg
My Home Page My Pelican Gallery page My Porsche Owners Gallery Page

[Doug Zielke]

Bill and Bill are right on the mark. Weight costs HP big time! My SC holds around 80 litres of fuel. If I run her down to the last quarter or so, I can definitely feel the improvement in acceleration.

But as for giving up beer....Nah.
It would be far less painful to buy a 930.

------------------
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
The Blue Bomber's Website

[Doug Zielke]

What about NOx?
Anybody here have a "Bottle Baby"??

------------------
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
The Blue Bomber's Website

[roGERK]

wckrause - you may well be onto something there...

Colin Chapman (enginer and founder of Lotus) claimed that racing drivers should be like jockies - as light as possible.

He felt it was pointless spending thousands of bucks and hours on shaving a few pounds off a racing car only for some big heavy driver to settle into the driver's seat.

Certainly, all of the competition versions of the 911 featured obsessive weight pairing - even to the extent of deleting the passenger sun-visor and leaving off the underseal.

- roGER

[wckrause]

Tell that to AJ Foyt. He had to have a special made tub to fit around his fat ass. Still, he won a few races.

------------------
Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

[carnut169]

Originally posted by Clark Griswald:
Need to be carefull about vendor claimed hp and real world.

MAF for example gives nowhere near 38 hp. According to B. Anderson, it's good for about 7 hp.

And I would like to see the elusive 16 hp chip.

Clark- that is exactly why I would like to get real #'s from this BBS....


Things like engine size, type of mod, cost, and hp improvement.


If we get enough answers (real answers) I can put a list together that would help members prioritize the mods they want to do based on actual results and actual costs.


How many posts have you read about "What should I expect to gain from....?"


Or, "How can I add hp to my 2.7....?" Etc etc etc.


I think if we put our experience and resources together we can have a meaningful list.


------------------
87 Carrera Cabriolet

[Jack Olsen]

It's a good idea, but it should have an appendix in the back devoted to the other costs of power (imrpoved cooling, brakes, suspension). Smog can be an issue, too. For people starting from scratch, buying a pre-74 tub (no smog inspections, at least in California) can save you a lot of headaches down the road.

Engine swaps can be hard to quantify, too. I gained 140 hp with an $8,000 swap ($57 per horse gained), but that's because the engine I was replacing only had 125 to start with. If I was upgrading a 3.2, the cost per horse would be higher.

------------------
Jack Olsen
My Rennlist page • My Pelican Gallery page • My Porsche Owners Gallery page

[This message has been edited by JackOlsen (edited 08-15-2001).]

[POVI]

How about my current v8 911 project ..

complete hi-performance v8 engine 383 ci
480 hp , 515 tq , completely tuned and dynoed + checked and adjusted $8400

v8 adapter kit and alum radiator $2800
misc, mods elec fuel pump, etc .. $1000

930 brake and suspension upgrades $00
(dont count for engine swap )
beefed 930 shortend trans + cv axles $1200

minus sold 911 engine and trans for $4200

totals:
engine $8400
trans $1200
adapter$2800
misc. $1000

total $13,400
sold parts - $4200 ( 911 engine + trans )

net cost $9,200

hp gain .. 180 stock hp. 911
vs 480 hp. v8 = 300hp gain
+ 340 ft lbs. torque

net cost for 300hp/340 tq. gain = $30.60 per hp

weight 2600lbs + 480hp /515tq = Violent acceleration

- Joe -
webmaster@sqlwarehouse.com

[rscupper]

Very interesting. I'm doing my first racer project - started in February and should be done in about 8 weeks, HAH! I don't know how many of us on the board are in SoCal, but if someone seriously wants to compile data my car 'should' be available by end of August for dyno testing (publisher-paid needed). Don't laugh - I'm taking a slightly tweeked 2.7 CIS to carbs, 906 cams, about 10.5:1, etc., etc.... The weight savings idea has not been lost on me, either. I'm going from factory 2,450 lbs to est. <2,000. Club class? WHO CARES!

[pwd72s]

" posted 08-15-2001 09:06 AM
--------------------------------------------------------------------------------
The other interesting thing is the whole weight-hp ratio. I was watching "Junkyard Wars" (show on TLC where two teams are assigned an item to build- rockets, race-cars, demo machines, whatever- but it has to be built out of stuff they find in the junkyard) and the assignment was dragsters. One of the teams used a v8, and a heavy set-up, the other used a very light frame and it was powered w/ a motorcycle engine. I don't know who won- (I fell asleep) but the interesting thing was something they said about weight and hp....

Again, I was sleepy, but they said something like for every 4lbs added, the engine needed another hp to maintain the same 0-60 times. If you use the formula for computing hp (The formula is: hp = weight * (speed / 234)3 ) This method uses the weight of the car and the speed at which the car completed the quarter-mile run. If you don't want to do the math this link will do it for you!

http://www.dsm.org/tools/calchp.htm


So anyway, the least expensive way to add hp would be to eliminate weight..."

Carnut, WHY did you write that? Now my wife says I need to visit Jenny Craig, whoever she is, instead of spending money on the 911.


[This message has been edited by pwd72s (edited 08-15-2001).]

[rscupper]

LITE BEER! FASTER CAR!

[Jack Olsen]

Oops.

[This message has been edited by JackOlsen (edited 08-15-2001).]