The Twin Screw Thread
12-27-2005, 11:58 PM
#526
Three Wheelin'
Join Date: Nov 2003
Location: Los Angeles, CA
Posts: 1,577
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by all4woody
Mike,
I saw the boost guage change from 7.5 to 8.5 with the pulley change. I think I have the 63mm pulley on at the moment. Marc says the headers should give 25-30 hp, but I think that is for a NA car. Since I did not see a boost with the additional psi, I would think the headers would give me a bit more. 500rwhp is the goal (for now) as long as it keeps running good.
Thanks, Woody
I saw the boost guage change from 7.5 to 8.5 with the pulley change. I think I have the 63mm pulley on at the moment. Marc says the headers should give 25-30 hp, but I think that is for a NA car. Since I did not see a boost with the additional psi, I would think the headers would give me a bit more. 500rwhp is the goal (for now) as long as it keeps running good.
Thanks, Woody
12-28-2005, 12:48 AM
#528
Nordschleife Master
Join Date: Sep 2004
Location: Not close enough to VIR.
Posts: 9,429
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by mspiegle
My first thought was that you had a small intercooler.... but the boost measurements comes after the IC so the intake ports themselves are seeing 8.5PSI. I *think* if the intercooler were a restriction, something strange would happen like only seeing a 0.5 raise in boost as oppose to the full 1.0 that a smaller pulley would offer.
I think Jim is right about the Devek Level II deal being dead, but Mark Anderson posted an alternative deal a month or so ago.
12-28-2005, 01:18 AM
#531
Addict
Rennlist Member
Rennlist Member
Join Date: Jul 2003
Location: Saskatoon Sask. Can.
Posts: 182
Likes: 0
Received 0 Likes
on
0 Posts
Woody,
What did you decide to do with the fresh air intake? There may be a restriction there. I tested the 3 1/2" intake pipe with no restriction at 8lbs boost but if the intake pipe is smaller or you are running more boost that may be a problem area as well. Another thought which I am sure you checked is belt slippage. John was eluding to belt slippage in an earlier post that was not easily detected.
What did you decide to do with the fresh air intake? There may be a restriction there. I tested the 3 1/2" intake pipe with no restriction at 8lbs boost but if the intake pipe is smaller or you are running more boost that may be a problem area as well. Another thought which I am sure you checked is belt slippage. John was eluding to belt slippage in an earlier post that was not easily detected.
12-28-2005, 08:23 AM
#533
Banned
Thread Starter
Join Date: May 2001
Location: The Great Northwest
Posts: 12,264
Likes: 0
Received 3 Likes
on
3 Posts
Ditto with belt slippage.
This is an odd one. I am sure the Murph kit has made over 500 without exhaust mods... maybe not?
This is an odd one. I am sure the Murph kit has made over 500 without exhaust mods... maybe not?
Originally Posted by Daryl
On second thought if you had a restriction at the intake you wouldn't see an increase in boost pressure
12-28-2005, 11:59 AM
#534
Range Master
Pepsie Lite
Lifetime Rennlist
Member
Pepsie Lite
Lifetime Rennlist
Member
According to Jim R, it does.....he said yesterday that he has the original cats and the RMB....(unless you consider the RMB to be an exhaust mod.....) Dynoed at 550, IIRC....
12-28-2005, 02:02 PM
#536
Three Wheelin'
Join Date: Nov 2003
Location: Los Angeles, CA
Posts: 1,577
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Daryl
Woody,
If possible try a run after disconnecting the exhaust pipes from the manifolds. Watch those A/F ratios.
If possible try a run after disconnecting the exhaust pipes from the manifolds. Watch those A/F ratios.
12-28-2005, 02:02 PM
#537
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Originally Posted by Daryl
Woody,
....try a run after disconnecting the exhaust pipes from the manifolds...
....try a run after disconnecting the exhaust pipes from the manifolds...
12-28-2005, 02:24 PM
#538
Addict
Rennlist Member
Rennlist Member
Join Date: Jul 2003
Location: Saskatoon Sask. Can.
Posts: 182
Likes: 0
Received 0 Likes
on
0 Posts
I was thinking on a dyno.
Reminds me of the drag race days. We would drive to the track with mufflers connected then unbolt the pipes from the headers. Can’t remember the time differences but were substantial. We would bolt a short length of exhaust pipe to the header flange to fine tune.
Mike, what makes a 928 run any different than any other high performance engine?
Reminds me of the drag race days. We would drive to the track with mufflers connected then unbolt the pipes from the headers. Can’t remember the time differences but were substantial. We would bolt a short length of exhaust pipe to the header flange to fine tune.
Mike, what makes a 928 run any different than any other high performance engine?
12-28-2005, 07:45 PM
#539
On the dyno I ran a 4" flex pipe from the MAF to the front of the car, this kept the air a little fresher. I would like to know for sure about Jim R's results, it seems at some point someone stated that it would be hard to get over 460 without headers. I am getting the exhaust upgrade either way, but if I can squeeze more out without it I would like to try. I have a local shop that will do mandral bent 3" dual, X-pipe and 2 Borla's for a good price, I have to see it to know how good a job it is.
As far as running on the dyno with open pipes, a PITA to remove while there, so that probably won't happen. Thanks again for the input. Later, Woody.
As far as running on the dyno with open pipes, a PITA to remove while there, so that probably won't happen. Thanks again for the input. Later, Woody.
12-28-2005, 07:58 PM
#540
Sharkaholic
Lifetime Rennlist
Member
Lifetime Rennlist
Member
I think you are more likely to run into fueling problems then exhaust, unless you have a clogged cat. Seem to remember Tim say in a past thread that the stock rails were insuficient for the job some where around the 500rwhp mark. But if you were going lean at 460 you should be seeing that. Curious?!