First Dyno run with custom SC-Problem #'s
#16
Burning Brakes
Thread Starter
Join Date: Jan 2005
Location: Phoenix, AZ
Posts: 1,032
Likes: 0
Received 0 Likes
on
0 Posts
Is the BOV adjustable? yes via spring what opens the valve is vacuum. As far as I know it bleeds anytime it is under vaccum or when you let of gas to create the neg vacuum. The pulley I use keeps boost a safe levels 7psi max.
Last edited by Mother; 12-09-2011 at 09:54 PM.
#19
Burning Brakes
Thread Starter
Join Date: Jan 2005
Location: Phoenix, AZ
Posts: 1,032
Likes: 0
Received 0 Likes
on
0 Posts
No growth in boost suggests a leak on the high pressure side of the intake. (Or the SC drive is slipping.) But I suspect a boost leak. If so, this can account for the lower output and the rich AFR since this air has been measured and the DME will fuel accordingly but the boost allows some air to bleed away and the result is the mixture is too rich.
Sincerely,
Macster.
Sincerely,
Macster.
Last edited by Mother; 12-06-2011 at 11:48 PM.
#21
Race Car
Just a thought; what air filter are you using? Is it sufficient to flow the CFM's needed for the Vortech?
Your AFR's seems fairly steady, so I'd think the timing might be getting out of whack possibly due to the knock control making for some of the very weird graphs your car produced?
Lastly, if the BOV is not staying closed, you are dumping boost - one of the biggest suspects I'd think.
Your AFR's seems fairly steady, so I'd think the timing might be getting out of whack possibly due to the knock control making for some of the very weird graphs your car produced?
Lastly, if the BOV is not staying closed, you are dumping boost - one of the biggest suspects I'd think.
#22
Burning Brakes
Thread Starter
Join Date: Jan 2005
Location: Phoenix, AZ
Posts: 1,032
Likes: 0
Received 0 Likes
on
0 Posts
Hey Tippy nice to see you're have not gone over to the dark side yet! The tuners said it looked fine and it does flow as I recall 890 cfm but pulling it off would not hurt and putting a sock over just for test. I will check the BOV, but interesting that past the problem area 5xxx RPM it can get 5.xx psi I would think it would just drop worse if BOV. Personally I do not understand how someone can tune the engine with just AFR/TQ and HP.?
#23
Race Car
Man, you have persistence! I remember you setting this car up years ago.
Anyways, the BOV if adjustable, will maintain/dump at a given PSI no matter what RPM until it's flow limitations are exceeded.
Wait a minute, are you sure you have the vacuum on the right side of the diaphragm? If it is wrong, you will be pushing the BOV open dumping boost.
If you could take the BOV completely off and block off the tubing, then you could rule it out.
Ignition timing still comes to mind with the weird crazy graph readings it produced on several different runs.
And to what others have said, these belts do slip and serpentines will. At your low boost settings, it should not, but anything north of 6 PSI per se can start to cause issues on the 6-rib setups.
How much percentage of the belt is making contact with the drive pulley? You need around 50% give or take.
Anyways, the BOV if adjustable, will maintain/dump at a given PSI no matter what RPM until it's flow limitations are exceeded.
Wait a minute, are you sure you have the vacuum on the right side of the diaphragm? If it is wrong, you will be pushing the BOV open dumping boost.
If you could take the BOV completely off and block off the tubing, then you could rule it out.
Ignition timing still comes to mind with the weird crazy graph readings it produced on several different runs.
And to what others have said, these belts do slip and serpentines will. At your low boost settings, it should not, but anything north of 6 PSI per se can start to cause issues on the 6-rib setups.
How much percentage of the belt is making contact with the drive pulley? You need around 50% give or take.
#24
Burning Brakes
Thread Starter
Join Date: Jan 2005
Location: Phoenix, AZ
Posts: 1,032
Likes: 0
Received 0 Likes
on
0 Posts
My understanding of the BOV is that it it does not matter which way it is mounted it just uses vacuum to open the valve and is closed by spring pressure which is adjusted by changing springs. Timing is on my mind 2 also took off dyno yesterday since it wanted to try it driving around on the last fuel map and still has a small drop in the 5000 rpm area the just takes off when I got home had a oil leak which is from the AOS/crankcase breather supply line to the Throttle body or in my case back just downstream of the MAF...I just put it back on before dyno testing but seems to have popped off again. I am going to take it to have put on a lift to have a new o-ring installed and make sure it is fastened properly. At this point the tuner has not requested any Durametric readouts on timing etc.?
The belt has at least 50% wrap and is tight.
The belt has at least 50% wrap and is tight.
#25
Banned
Join Date: Oct 2011
Location: Holy City, South Carolina
Posts: 2,391
Likes: 0
Received 1 Like
on
1 Post
You should be using a pop off valve for a supercharger. Not a dv. When using a dv on a MAF metered car the vent side needs to be routed back into the intake after the MAF sensor.
I take it this isn't your setup as I seemed to have over looked your added description on the picture of the outlet of that dv being hooked up to the inlet.
I take it this isn't your setup as I seemed to have over looked your added description on the picture of the outlet of that dv being hooked up to the inlet.
#26
Three Wheelin'
5k rpm is around the area original variocam returns cam timing back to normal from the advanced state. I can feel it on my car if I'm really concentrating. Wondering if you are just feeling this change "more" dramatically because of the FI. What does your cam deviation read out for both banks from durametric? And can you monitor the actual angles value through the rpm range to validate variocam is working right?
#27
Burning Brakes
Thread Starter
Join Date: Jan 2005
Location: Phoenix, AZ
Posts: 1,032
Likes: 0
Received 0 Likes
on
0 Posts
You should be using a pop off valve for a supercharger. Not a dv. When using a dv on a MAF metered car the vent side needs to be routed back into the intake after the MAF sensor.
I take it this isn't your setup as I seemed to have over looked your added description on the picture of the outlet of that dv being hooked up to the inlet.
I take it this isn't your setup as I seemed to have over looked your added description on the picture of the outlet of that dv being hooked up to the inlet.
#28
Burning Brakes
Thread Starter
Join Date: Jan 2005
Location: Phoenix, AZ
Posts: 1,032
Likes: 0
Received 0 Likes
on
0 Posts
5k rpm is around the area original variocam returns cam timing back to normal from the advanced state. I can feel it on my car if I'm really concentrating. Wondering if you are just feeling this change "more" dramatically because of the FI. What does your cam deviation read out for both banks from durametric? And can you monitor the actual angles value through the rpm range to validate variocam is working right?
I understand the kick you feel however some of the dyno runs of vf setups show a smooth torq/hp and afr despite the variocam which not familiar with what is supposed to do however mine simply wants to backfire like it's to rich then shoots straight up to WOT and hunts and dies after idling to much. I am hoping to get some SC durametric data for comparison.
I went to another dyno shop today to have a leak fixed and spoke with there programmer said that the AFR looked pretty good but of course ended up in a guessing game after we sat and watched it hunt and dye. We did agree that these newer cars cannot be tuned like they did back in the old days with more and more sensors.
#29
Drifting
Sorry I can't be more help ;-)
It's just been too long since I supercharged and tuned anything. My last was when I put a Judson blower on my '59 VW bug in the late '60s. It had a single throat Solex carb with a single mixture screw to turn and I could loosen the clamp on the '009 Bosch distributor to tweek the timing. It was fun, ran great and I'll bet it boosted that 36HP motor to about 50!
It's just been too long since I supercharged and tuned anything. My last was when I put a Judson blower on my '59 VW bug in the late '60s. It had a single throat Solex carb with a single mixture screw to turn and I could loosen the clamp on the '009 Bosch distributor to tweek the timing. It was fun, ran great and I'll bet it boosted that 36HP motor to about 50!