how much boost should a 68mm pulley on a good charger produce?
1 - 20 of 23 Posts
Joined
·
16,888 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (88mk2g60)
This depends on a few different factors.
Do you have a P&P head?
What crank pulley? (what year is your car?)
Any charger porting?
Cam?
Cam gear?
piston size stock?
If its a stock 1990 Corrado with a stock charger in good shape then you should see 15-16psi at redline (16.5 while bouncing of the revlimiter but this is not good for the charger)
P&P head will decrease the psi
1991&1992 larger crank pulleys will see anywhere from 1-3 psi increase
Porting on the charger "should" increase your psi
a cam will change your psi as will a cam gear's various settings
pistons being larger then stock will cause a drop also
This depends on a few different factors.
Do you have a P&P head?
What crank pulley? (what year is your car?)
Any charger porting?
Cam?
Cam gear?
piston size stock?
If its a stock 1990 Corrado with a stock charger in good shape then you should see 15-16psi at redline (16.5 while bouncing of the revlimiter but this is not good for the charger)
P&P head will decrease the psi
1991&1992 larger crank pulleys will see anywhere from 1-3 psi increase
Porting on the charger "should" increase your psi
a cam will change your psi as will a cam gear's various settings
pistons being larger then stock will cause a drop also
Joined
·
16,888 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (dackar)
-1-2 psi so about 14-15psi
-1-2 psi so about 14-15psi
| Quote, originally posted by dackar » |
| How much boost should the 68 mm pulley produce in a good P&P head ( mfa ) in a stock 90' G60 (stock piston, cams, crank pulley, etc...)? |
Joined
·
2,165 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (88mk2g60)
I have a stock head and cam and see 17-19 PSI on any given day with my 68MM pulley.....just before 6500 RPM and no bouncing off of the rev limeter.
![]()
I have a stock head and cam and see 17-19 PSI on any given day with my 68MM pulley.....just before 6500 RPM and no bouncing off of the rev limeter.
Joined
·
70 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (88mk2g60)
I hit 15 psi with a 68mm before I got a rebuild, afterwards with a RS port I hit 13 psi. I have been trying to find if there is a leak, but I can't find any.
I hit 15 psi with a 68mm before I got a rebuild, afterwards with a RS port I hit 13 psi. I have been trying to find if there is a leak, but I can't find any.
Joined
·
16,888 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (TexasCorradoG60)
crank pulley?
is your boost above 255 on the mfa?
| Quote, originally posted by TexasCorradoG60 » |
| I have a stock head and cam and see 17-19 PSI on any given day with my 68MM pulley.....just before 6500 RPM and no bouncing off of the rev limeter.
|
crank pulley?
is your boost above 255 on the mfa?
Joined
·
16,888 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (RockHarder)
boost leaks are the enemy
| Quote, originally posted by RockHarder » |
| I hit 15 psi with a 68mm before I got a rebuild, afterwards with a RS port I hit 13 psi. I have been trying to find if there is a leak, but I can't find any. |
boost leaks are the enemy
Joined
·
70 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (G60ING)
Tell me about it! I didn't have one before I got the rebuild, but I can't understand why I would get less boost with a port unless there was a leak somewhere. It's very frustrating, I need more boost!
| Quote, originally posted by G60ING » |
boost leaks are the enemy |
Tell me about it! I didn't have one before I got the rebuild, but I can't understand why I would get less boost with a port unless there was a leak somewhere. It's very frustrating, I need more boost!
Re: how much boost should a 68mm pulley on a good charger produce? (G60ING)
this is correct...PSI is a way to measure resistance. porting with increase CFM but lower PSI
| Quote, originally posted by G60ING » |
| some times when you port you loose psi but gain cfm |
this is correct...PSI is a way to measure resistance. porting with increase CFM but lower PSI
Re: how much boost should a 68mm pulley on a good charger produce? (IMNOBUG)
I rebuilt my charger at Christmas and got 1.4 BAR the other day. The charger was ported at Jabbasport 2 years ago when I first had it rebuilt. Got 68mm, red tops and SNS stage 5.
Gavin
I rebuilt my charger at Christmas and got 1.4 BAR the other day. The charger was ported at Jabbasport 2 years ago when I first had it rebuilt. Got 68mm, red tops and SNS stage 5.
Gavin
Re: how much boost should a 68mm pulley on a good charger produce? (IMNOBUG)
I've been wondering the past few days, after reading a few topics involving airflow, is pressure the true measure of how much "boost" you get, or should CFM (amount of air flowing, correct?) be taken into account? I figure that both would matter, because if you have bigger ports (anywhere) more air will be able to flow, and the whole point is to get more air into the compression chamber to burn at once. At least that's my understanding of it
![]()
Someone want to clarify this a bit?
Dave
| Quote, originally posted by IMNOBUG » |
| this is correct...PSI is a way to measure resistance. porting with increase CFM but lower PSI |
I've been wondering the past few days, after reading a few topics involving airflow, is pressure the true measure of how much "boost" you get, or should CFM (amount of air flowing, correct?) be taken into account? I figure that both would matter, because if you have bigger ports (anywhere) more air will be able to flow, and the whole point is to get more air into the compression chamber to burn at once. At least that's my understanding of it
Someone want to clarify this a bit?
Dave
Joined
·
13,009 Posts
Re: how much boost should a 68mm pulley on a good charger produce? (blakeyez)
I'm still a bit confused by the whole psi/cfm/port thing, but you're right, the goal is to get more air into the system. To paraphrase what someone else said in a different thread, when dealing in psi you have to be sure you're talking apples to apples. A ported charger (or head) pushing 15 psi vs a stock charger pushing 15 psi are two way different things.
Brian
I'm still a bit confused by the whole psi/cfm/port thing, but you're right, the goal is to get more air into the system. To paraphrase what someone else said in a different thread, when dealing in psi you have to be sure you're talking apples to apples. A ported charger (or head) pushing 15 psi vs a stock charger pushing 15 psi are two way different things.
Brian
Re: how much boost should a 68mm pulley on a good charger produce? (ButchHusky)
My motor had 80k and was running top notch with all the basics replaced. The charger was rebuilt to stock specs not too long before I put a 68 on it, 3.5 bar fpr, stage 4 chip and I only saw 11 psi max at redline. I searched and searched for any contributors but everything looked fine. A buddy of mine has the exact setup on his rado but his charger was just built be jabbasport and ported and he only sees 13 max...what gives???
![]()
My motor had 80k and was running top notch with all the basics replaced. The charger was rebuilt to stock specs not too long before I put a 68 on it, 3.5 bar fpr, stage 4 chip and I only saw 11 psi max at redline. I searched and searched for any contributors but everything looked fine. A buddy of mine has the exact setup on his rado but his charger was just built be jabbasport and ported and he only sees 13 max...what gives???
Re: how much boost should a 68mm pulley on a good charger produce? (GTiG6O)
well if you kept the silecer box you probabley didn't get a good seal and they normally leak when taken apart and reassembled. ditch it and get a rallye outlet 3 or 6 fin it doesn't matter, with a dremel and half an hour you can make a 6 fin a 3 fin and there is really no difference in them they just eliminate a leaky silencer box. http://****************.com/smile/emthup.gif
well if you kept the silecer box you probabley didn't get a good seal and they normally leak when taken apart and reassembled. ditch it and get a rallye outlet 3 or 6 fin it doesn't matter, with a dremel and half an hour you can make a 6 fin a 3 fin and there is really no difference in them they just eliminate a leaky silencer box. http://****************.com/smile/emthup.gif
Re: how much boost should a 68mm pulley on a good charger produce? (IMNOBUG)
I have a BBM rebuilt charger (stock spec) and a Neuspeed 68 mm. Correct size belt and the tensioner seems strong, I get 10 psi at 3200 rpm, but only like 10.5 psi at 6000 rpm. I've retightened all connections except the un-reachable ones by the intercooler. I'm hoping to find a boost leak down there.
I have a BBM rebuilt charger (stock spec) and a Neuspeed 68 mm. Correct size belt and the tensioner seems strong, I get 10 psi at 3200 rpm, but only like 10.5 psi at 6000 rpm. I've retightened all connections except the un-reachable ones by the intercooler. I'm hoping to find a boost leak down there.
1 - 20 of 23 Posts
Join the discussion
