Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

79 Performance

Thread Tools
 
Search this Thread
 
Old 05-19-2006, 06:44 PM
  #16  
Jim bailey - 928 International
Addict
Rennlist Member

Rennlist
Site Sponsor

 
Jim bailey - 928 International's Avatar
 
Join Date: Jul 2001
Location: Anaheim California
Posts: 11,542
Likes: 0
Received 3 Likes on 3 Posts
Default

Based on Hacker's post the exhaust makes 30 HP difference so the 4 speed upgrade with much lower first gear it would be quicker !
Old 05-19-2006, 06:49 PM
  #17  
TAREK
Three Wheelin'
 
TAREK's Avatar
 
Join Date: Oct 2002
Location: Clearwater Beach, Florida
Posts: 1,579
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Jim bailey - 928 International
Based on Hacker's post the exhaust makes 30 HP difference so the 4 speed upgrade with much lower first gear it would be quicker !
I'm in the middle of this job as we speak.

Yes the 3spd is a dog off the line, but once the revs are beyond 3200 rpm or so, I found little difference from later cars (staying in 2 of course)
Old 05-19-2006, 06:55 PM
  #18  
Dave Howerdel
Three Wheelin'
 
Dave Howerdel's Avatar
 
Join Date: Apr 2004
Location: Central NJ
Posts: 1,990
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Jim bailey - 928 International
Based on Hacker's post the exhaust makes 30 HP difference so the 4 speed upgrade with much lower first gear it would be quicker !
Wait, Your saying that different gearing will make it quicker? What elese does gearing affect? Perhaps we should discuss this Gearing thing a bit further?
Old 05-19-2006, 06:56 PM
  #19  
FlyingDog
Nordschleife Master
 
FlyingDog's Avatar
 
Join Date: Sep 2004
Location: Not close enough to VIR.
Posts: 9,429
Likes: 0
Received 2 Likes on 2 Posts
Default

Can you put 3.09 r+p in a 3 speed?
Old 05-19-2006, 06:57 PM
  #20  
hacker-pschorr
Administrator - "Tyson"
Lifetime Rennlist
Member
 
hacker-pschorr's Avatar
 
Join Date: Aug 2001
Location: Up Nort
Posts: 1,604
Received 2,225 Likes on 1,254 Posts
Default

My 79 should have the 2:75 & does have LSD.
Old 05-19-2006, 06:58 PM
  #21  
neilh
Rennlist Member
 
neilh's Avatar
 
Join Date: Mar 2004
Location: Southport, NC
Posts: 1,602
Received 7 Likes on 3 Posts
Default

Originally Posted by BrendanC
By no means a disrespect Neil. I put headers, cams, and a dual 2.5 on my wife's 81 when I did a 4spd conversion, and I think was basically as quick as the 4.7L 4spd autos. Basically.
No problem, after driving it for 25 years I know how it runs and what to expect!
Reaction time sometimes makes up for slow launch and foot on brake, gas until it hits 3k, foot off brake gives it a little extra jump...

Are you going to be around this sunday afternoon, would love to stop by...

Neil
Old 05-19-2006, 07:08 PM
  #22  
BC
Rennlist Member
 
BC's Avatar
 
Join Date: Dec 2001
Posts: 25,152
Received 87 Likes on 56 Posts
Default

Originally Posted by neil30076
No problem, after driving it for 25 years I know how it runs and what to expect!
Reaction time sometimes makes up for slow launch and foot on brake, gas until it hits 3k, foot off brake gives it a little extra jump...

Are you going to be around this sunday afternoon, would love to stop by...

Neil


Yes, Sunday hopefully will see some gains from today, when the fun starts with trying to switch suspension pieces and exhausts among THREE 928s to get them where they need to be for thier next stages in life. I wouldn't at all mind some extra eyes and hands either Saturday OR sunday.
Old 05-19-2006, 07:28 PM
  #23  
laneskelton
Pro
 
laneskelton's Avatar
 
Join Date: Nov 2005
Location: Santa Cruz, CA.
Posts: 539
Likes: 0
Received 0 Likes on 0 Posts
Default

Your distributer could be a little off too, if its sluggish off the line. I have never driven an auto 928, but on my 5 speed the distributer was retarded a little too much and a simple twist woke the car up off the line, made it rev faster.
Old 05-19-2006, 07:30 PM
  #24  
neilh
Rennlist Member
 
neilh's Avatar
 
Join Date: Mar 2004
Location: Southport, NC
Posts: 1,602
Received 7 Likes on 3 Posts
Default

Originally Posted by BrendanC
Yes, Sunday hopefully will see some gains from today, when the fun starts with trying to switch suspension pieces and exhausts among THREE 928s to get them where they need to be for thier next stages in life. I wouldn't at all mind some extra eyes and hands either Saturday OR sunday.
Brendan, just sent you a PM
Neil
Old 05-19-2006, 09:05 PM
  #25  
pewter82
Drifting
 
pewter82's Avatar
 
Join Date: May 2004
Location: Middle Missouri
Posts: 2,350
Likes: 0
Received 2 Likes on 2 Posts
Default

Remember this is 1979 performance and it was probably pretty decent in its day, just feels slow by todays standard. My 82 auto was very slow off the line, but top end was very nice and seemed very controlable at speed.

jason
Old 05-19-2006, 09:14 PM
  #26  
Jim bailey - 928 International
Addict
Rennlist Member

Rennlist
Site Sponsor

 
Jim bailey - 928 International's Avatar
 
Join Date: Jul 2001
Location: Anaheim California
Posts: 11,542
Likes: 0
Received 3 Likes on 3 Posts
Default

The Corvette of that time base 350 L48 was 180 HP the "performance" L82 max was 230 HP ....Horsepower was simply NOT IN FAVOR in that era !
Old 05-19-2006, 09:23 PM
  #27  
SMTCapeCod
Race Car
 
SMTCapeCod's Avatar
 
Join Date: Jul 2005
Location: Mechanochondriacism
Posts: 4,700
Received 22 Likes on 15 Posts
Default

That torque number isn't half-bad, IMHO. And its at a nice place on the curve. That oughta lend a little pep off the line, shouldn't it?
More on-topic, my 83 Euro 5 spd is a different animal, but shares the CIS. It is noticeably happier down low with a fatter (richer) AFR.

Originally Posted by Hacker-Pschorr
Start with headers, recent dyno with my 79 5-speed. Stock engine with MSDS headers:

1979 US - 928 5-speed. 100% stock except for MSDS headers and custom Y-into a single exhaust - no muffler:
228.1rwhp @ 5,023rpm
282.6rwtq @ 3,848rpm
Old 05-19-2006, 11:06 PM
  #28  
PorKen
Inventor
Rennlist Member

 
PorKen's Avatar
 
Join Date: Sep 2002
Posts: 10,174
Received 412 Likes on 228 Posts
Default

Advancing the valve timing will give you more grunt off the line with the three speed automatic. (3 cam degrees works well for me.)

On a '79, it is easy to do, with Mercedes offset cam keys:

clic pic for thread
Old 05-20-2006, 02:15 AM
  #29  
SharkSkin
Rennlist Member
 
SharkSkin's Avatar
 
Join Date: Jan 2004
Location: Boulder Creek, CA
Posts: 12,620
Likes: 0
Received 6 Likes on 6 Posts
Default

Frank, easiest way to get that car to leave the line faster would be a healthy dose of wheelspin to get the RPMs up. 40psi or so in the rears ought to do it...
Old 05-20-2006, 02:56 AM
  #30  
hacker-pschorr
Administrator - "Tyson"
Lifetime Rennlist
Member
 
hacker-pschorr's Avatar
 
Join Date: Aug 2001
Location: Up Nort
Posts: 1,604
Received 2,225 Likes on 1,254 Posts
Default

Originally Posted by SMTCapeCod
That torque number isn't half-bad, IMHO. And its at a nice place on the curve. That oughta lend a little pep off the line, shouldn't it?
More on-topic, my 83 Euro 5 spd is a different animal, but shares the CIS. It is noticeably happier down low with a fatter (richer) AFR.
1st gear is all tire spin (even with my new 10x18) if I'm not careful. I can usually spin the tires in 2nd gear just by flooring it while moving (no clutch slipping tricks). My 79 is very healthy - proof these cars must be driven and driven hard. It only has 67,000 miles on it, but at least half of those were on the track or getting the **** beaten out of it on the street (I know or know of every owner this car has ever had, very colorful history).


Quick Reply: 79 Performance



All times are GMT -3. The time now is 06:16 AM.