Notices
911 Turbo (930) Forum 1975-1989

Dyno results!

Thread Tools
 
Search this Thread
 
Old 12-21-2005, 01:53 PM
  #46  
ChristianR
Three Wheelin'
 
ChristianR's Avatar
 
Join Date: Oct 2005
Location: Memphis/Chicago
Posts: 1,611
Received 140 Likes on 71 Posts
Default

700hp/tq at the wheels is not easy to achieve. It is if you spend a ton of money and re-do practically everything in the engine. I have done this and at the moment we estimate my car to be in the mid 500's at the wheels, I will have it dyno'd after the new year.

It's very very quick, but very expensive to get it there as well.

Christian
Old 12-21-2005, 01:54 PM
  #47  
special tool
Banned
 
special tool's Avatar
 
Join Date: Apr 2002
Location: limbo....
Posts: 8,599
Likes: 0
Received 1 Like on 1 Post
Default

Oh God no!!! I am NOOOOOT saying it is easy!!!!!!!
When I said "easy'< I meant that the engine could easily withstand the power.

I am saying that EFI is a much better way to get there.

I am the last person on the planet who would say that getting power out of ANY 2 valve, low-rev Porsche is easy.
Old 12-21-2005, 01:55 PM
  #48  
jhunt@huntinter
Pro
 
jhunt@huntinter's Avatar
 
Join Date: Jul 2003
Posts: 605
Likes: 0
Received 0 Likes on 0 Posts
Default

Over 450 hp and these cars start to get unmanageable by all but the best drivers (in fact the number is probably far lower). A

You also have to consider the entire drivetrain if you are going high hp. Consider what the factory had to do to support the 700/800hp 935's hp. There was a lot of titanium used.

And not a few drivers hated the 935 car because it was dangerous. But then again, the drivers on this board are much better then the silly LeMans drivers.
Old 12-21-2005, 02:02 PM
  #49  
special tool
Banned
 
special tool's Avatar
 
Join Date: Apr 2002
Location: limbo....
Posts: 8,599
Likes: 0
Received 1 Like on 1 Post
Default

Also - consider guys that 2 valve Porsches have a RIDICULOUS torque rise. Like a 2 stroke. Very vicious. There are ways of moving the curve to the right, but do you want to?
This and wider tires can tame the 2 valve turbo Porsche.

My point is that these things are much easier to vary (even track by track ) with EFI.

My friend has a T67 Supra (real one) Nothing like the torque hit of the Porsche, but very strong on the top end. (I helped him tune the AEM.... )
Old 12-22-2005, 12:11 AM
  #50  
My87Targa
Racer
 
My87Targa's Avatar
 
Join Date: Jul 2005
Location: Maryland
Posts: 489
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by BrianKeithSmith
Man, there's an echo in this thread....
hello..HELLO...HELLO!!!!!



hmm what echo??
Old 12-22-2005, 12:19 PM
  #51  
srf506
Three Wheelin'
 
srf506's Avatar
 
Join Date: Aug 2005
Posts: 1,980
Likes: 0
Received 0 Likes on 0 Posts
Default

Gee, unless you're a drag racer why do you want to make more than about 500 - 650 hp anyway? Fuel consumption goes to h _ _ _ - in - a - handbasket. You better be bringing tons of gear sets with you to get the motor dialed - in to use that horsepower, and the wear and tear on everything is exponential. For the street its even less practical. Here in the U.S. its getting really tough to have any fun in a car at speed anymore unless you're going to DE events. If you're doing that why not just go ITS or Spec - something racing in the SCCA? But to each his/her own. I'm perfectly happy with my ~ 400 HP in my 99% stock 930. I can almost own another Carrera or even a 930 with the cost to boost the horsepower up significantly. I'm thinking fleet ownership, a different model and color to drive everyday of the week! ;-)
Old 12-22-2005, 03:51 PM
  #52  
WERK-I
Pro
 
WERK-I's Avatar
 
Join Date: Jan 2002
Location: Wisconsin, formerly of Boston
Posts: 571
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Sameer
I increased the CO today to abt 5% and Brian you are correct it made only a small difference. If I fatten the CO anymore, the idle gets really lumpy so I've basically maxed it out. I guess the K29 turbo is too much for the CIS not forgetting I got 3.4 P&C's. Anyway the only way to solve this problem is to go EFI.

When they did the dyno run, the a/f ratio was between 11-12 all the way upto 5000rpm than went all the way upto 13.504 at 6178rpm. So for now till I go EFI I shall keep it below 5000revs. No choice.
Sameer,
You are not listening to the advice that has been given on this thread. You have fallen into the common trap of throwing parts on an engine platform that are not complementing each other. You have added a K-29 turbo, wilder cams, increased displacement, added headers and hi-flow muffler and now you are wondering why it's leaning out on the top-end? You have done everything to deliver more air to the combustion chamber, but have done nothing to insure the fuel delivery curve matches(complements) the increased VE of your mods.

Take the advice of others and get your fuel head modified....EFI is not going to solve your problem inexpensively. It's your money and my $0.02.

Dave
'85 Factory Slantnose 930
Old 12-22-2005, 04:26 PM
  #53  
DonE
Burning Brakes
 
DonE's Avatar
 
Join Date: May 2005
Location: St Johns, FL
Posts: 794
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by WERK-I
Sameer,
You are not listening to the advice that has been given on this thread. You have fallen into the common trap of throwing parts on an engine platform that are not complementing each other. You have added a K-29 turbo, wilder cams, increased displacement, added headers and hi-flow muffler and now you are wondering why it's leaning out on the top-end? You have done everything to deliver more air to the combustion chamber, but have done nothing to insure the fuel delivery curve matches(complements) the increased VE of your mods.

Take the advice of others and get your fuel head modified....EFI is not going to solve your problem inexpensively. It's your money and my $0.02.

Dave
'85 Factory Slantnose 930

Well put....

How many owners have we seen throw all those (bolt-on) mods on their cars and be disappointed at the dyno? Ahhh, excuse me - allow me to step to the front of the line....
Old 12-22-2005, 05:29 PM
  #54  
Geoffrey
Nordschleife Master
 
Geoffrey's Avatar
 
Join Date: Dec 2001
Location: Kingston, NY
Posts: 8,305
Likes: 0
Received 12 Likes on 10 Posts
Default

I have to say that that with the proper gearing, my 89 with 550hp and MoTeC was a joy to drive at the track and had over 8 years of track abuse on it with very few issues. I did strip all the teeth off of 3rd gear last year, but it really should have been replaced when the gearbox was serviced the prior year as preventative maintenance. I will say that when turned up to 700hp it wasn't any faster around the track but it was more difficult to drive. In 550hp configuration, it was far easier than a stock turbo with less lag and it had a T66 turbo (much bigger than a k29). On the street the car just became too much and wasn't really any fun any longer since it put you into ticket territory too fast. Oh, 400mi to a tank on the highway too.

I'll agree with Special Tool that there is no comparison to EFI. It is far better and more reliable in every sense...properly tuned of course.
Old 12-22-2005, 10:37 PM
  #55  
Sameer
Race Car
Thread Starter
 
Sameer's Avatar
 
Join Date: Aug 2002
Location: Singapore
Posts: 3,811
Likes: 0
Received 2 Likes on 2 Posts
Default

I get the hint guys..
Old 12-23-2005, 08:18 AM
  #56  
Bill935K3
Racer
 
Bill935K3's Avatar
 
Join Date: Mar 2004
Location: Swansea MA
Posts: 286
Likes: 0
Received 0 Likes on 0 Posts
Default

My old 3.4 CIS race motor. With 2 PMS K-24's mucho head work 7.5-1 and two GM electronicly controlled injectors mounted on the intake plenum and runnitn VP C12, These are Rear Wheel from when we were tuning the injectors for to enhance fuel IE lifting out when it got too lean
Call it 475 HP and 500 ft lbs. Once we got this motor right I ran it for a lot of hours. New pistions and valve guides every year and complete with cams rockers and jugs every other year
Attached Images   
Old 12-23-2005, 09:54 AM
  #57  
slownrusty
Rennlist Member
 
slownrusty's Avatar
 
Join Date: Apr 2005
Location: Houston, TX
Posts: 2,875
Received 337 Likes on 156 Posts
Default

Impressive set-up Bill!
Old 12-23-2005, 12:41 PM
  #58  
DonE
Burning Brakes
 
DonE's Avatar
 
Join Date: May 2005
Location: St Johns, FL
Posts: 794
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Geoffrey
[snip]

I'll agree with Special Tool that there is no comparison to EFI. It is far better and more reliable in every sense...properly tuned of course.
G - you knew I couldn't walk away from this one.

Your comment is completely correct on its own. We differ in opinion when you take a properly tuned CIS car and convert to EFI. A well tuned CIS car is reliable, drivable and delivers good power/torque, so EFI conversions make much less sense when you factor the cost vs benefit.

No doubt my EFI conversion gives me control over timing, fuel delivery, accel, decel and so on, but for the typical turbo driver, the CIS is pretty competent and it delivers consistently.

I like my EFI conversion (now) because I can start playing with different configs. For example, I am going to play with a custom cam grind to see how I can tune it better (for what I want) than the current grind. Can't do that with CIS - you basically install and go.

Anyway, CIS is extremely competent, reliable and drivable in the hands of a competent tuner. Same can be said for EFI.

Happy Holidays



Quick Reply: Dyno results!



All times are GMT -3. The time now is 11:57 PM.