|09-12-2004 08:47 PM|
Ok I thought that there was no difference in the two heads except for cam size but Iím not even sure about that? Can someone clarify this? What is the difference between the two heads? The cam size? And is there a difference between the exhaust cam and the intake cam? Because Iím in the middle of rebuilding a head for my car and the head that I got had bent valves from a timing chain failure and I noticed that the only valves that where bent where the exhaust valves. So that leads me to believe that there is a higher lift on the exhaust side than the intake side is this true? Overall do you guys know would be better to go with 2.3L cams or 2.0L cams on a turbocharged application?
|09-12-2004 03:33 PM|
I definately need to figure out whats up with this as well, because recently i found a problem.
Unfortunately, I had an exhaust manifold bolt break of inside the head, and its causin an exhaust leak. Since I have to remove my head to fix this problem... Im planning to replace my head with a 2.3L, and get my manifold coated.
So please clarify what needs to be done if i'm to do this as well as the gains if any.
|09-11-2004 09:32 PM|
|BurnsSide42||well I am going with 1985 Turbo Cams from a 2.0L for my 1989 SPG Project - Apparently these are the best cams for MY purpose - HOWEVER - a N/A 2.3 is the next best if it's like a 92/93 9000 they are coming from. - as for you newer folks - not 100% sure there.|
|09-11-2004 09:28 PM|
So your saying that you will get a longer lift with 2.3L cam on a 2.0L? and intern about a 15 hp increase on a T5 turbo? Am I getting this or is there less of a lift on a 2.3L? Just to clarify this for me.
Thanks A lot
|07-28-2004 09:25 AM|
|mike saunders||How difficult is a cam switch? (I have a 2.0 B204 head that will be taking up space soon...would the cams swap out into a B205R?...and would it even be worth the effort?)|
|07-28-2004 09:09 AM|
|BurnsSide42||ok - so for a 1986 Turbo block having a 2.1 head put onto it - what would be my ideal cam shaft combo? I have a set of each 2.0 2.1 and 2.3 - Which one goes where (intake/exhaust) ? Anyone know which would be best for performance and sound? Thanks!|
|07-28-2004 07:47 AM|
Hey thanks Nick and Adrian for you help. I'm understanding about it better now. I'm still going to be reading about it.
Just ordered a JT3" from you nick, i'm the one that kept calling about it being stainless. Cant wait to get it thanks.
|07-28-2004 07:10 AM|
ty Nick! Always good to have you around.
To be pedantic the most aggressive factory Saab cams are on C900T's. The only reason those cars don't get moster power in stock form is due to the poorly flowing cyllinder heads the 2.0's had.
I'm unsure if those longblock cams are compatible with the shortblock heads though. I know the heads and blocks have to have significant machining done to match.
|07-28-2004 07:10 AM|
You may find that the specs have changed if the cams are worn. But these are the specs Saab listed. Also I believe the Saab specs are seat to seat, some people may list the specs as .050 - .050 lift ... which is slightly different. In order to compare to the Saab specs I think they'd have to be seat to seat.
There is a page here with all of the Saab cams specs and the combustion spaces of some of the earlier Saab cyllinder heads. None of the new heads, but has some of the newer cams.
The reason for putting "less aggressive" cams on the newer Saabs is that the Trionic 7 cyllinder head flows better than it's previous counterpart used on T5. I believe this is mainly due to smaller valves which have smaller stems and allow the air to flow more easily into the cyllinder.
Because the head itself flowed better, the cams didn't need to be as aggressive to get the desired power output. It also improves spool up to have a fairly non-aggressive exhaust cam because reducing the duration and lift increases exhaust gas velocity.
Never hurts to get a head port and polished, if you're looking to have this done see if you can get them to recess the valve guides. (See attached photo courtesy of ylee coyote of SaabScene and his monester Aero.)
Anyhow, using desktop dyno and entering the Saab specs as best I could (which should be pretty accurate as I now have exact valve sizes) I was able to acertain that it should be good for about 15 hp on older T5 cars (it depends on knock sensitivity) and would be good for 30 hp on T7 cars except that T7 will just pull back boost if the head flows better (same airmass) so you only see an increase in power from the reduction in pumping losses created by lower intake and exhaust pressure. Probably a bit less. Also note that the cams will change the powerband towards the high end slightly.
The DeskTop dyno is a wonderful program. It can be run on nearly any computer, and it's been designed from the ground up by some SAE engineers who got together with some software writers. It actually calculates frictional losses and has programmed engines of a number of different kinds. You can input valve diameter, ported or stock head, bore, stroke, compression ratio, exhaust design.
The cams should pretty obviously increase the power some as they have an extra 6 degrees of intake and exhaust duration. Unless you want a 7K+ redline and almost no low end they're about as aggressive as you can go. IMHO
|07-28-2004 07:01 AM|
I posted the specs when I tried them in my Viggen. (t7 afm)
Saab "less aggressive" profiles = Higher torque with the compromise being top end power.
Since we have not tried this on t5, I would recommend after changing cams having a wideband o2 connected to monitor fueling. I do not know how the change in Volumetric Efficiency will affect the fuel system.
|07-28-2004 05:47 AM|
Thanks Adrian for your input. I wonder why Saab would use less aggressive cams on their so called high-performance cars, such as the Aero and the Viggen.
Also do you have a site that you reference to, or some kind of book? I would like to read about some more info on the engines and all the specs.
|07-28-2004 05:44 AM|
|Tweek's Turbos||I have yet to get my specs back, but Saabtuner has answered.|
|07-28-2004 12:08 AM|
The cams from the 9-5 Aero are the same as the Viggen.
Cam specs for B235R are in bold (and 2.3 naturally aspirated in italics) are as follows:
.327" .341" of lift
Intake Duration: 231 246
Exhaust Duration: 231 246
Even the stock cams for the 2.0 are more agressive than the ones on the Viggen/Aero. So unless MapTun was de-engineering the camshafts?
The stock 2.0 turbo (B204L) has .341" lift, and 240 degrees duration intake and exhaust.
The Saabs with really un-aggressive cams are the B205R, and B235E.
|07-27-2004 08:49 PM|
2.3 cams on a 2.0
Hey tweek, you said that your shop was running tests on the cams. I have a feeling that for Stage 6 on maptuns site for the NG900, this is what they use for upgraded cams.
Let me know how the results come out. I have been talking to cedric about this, and some other people. I'm pretty sure that they use the cams from a 9-5 Aero. I could be wrong, but keep me posted.