Question on DIS-2

[Mike 99GSX]

I have been having timing problems during spoolup. At this point, I think I may be at my VPC's brain power as far as being able to fool my ECU on airflow signal. I'm looking for a way to retard my ignition timing during to spoolup to improve lag. Is it true that I can do this with a DIS-2? I'm not quite ready to switch to an EMS yet so I'm looking for another alternative to fixing this problem.

 

[brads]

With a standard DIS-2, you can't really do what you are asking for. Maybe if you get some of their add on modules you could. Or if you went with one of the programmable DIS-2 setups, you could. But now you are starting to talk about a lot of money to try to fix a problem thats basically the result of your other choice of electronics(VPC).
It might be worth it to consider an alternative to the VPC/GCC combo instead. If you have your heart set on the VPC but want to be able to tune your timing as your boost comes on, using something like an emanage would give you the ability to adjust the timing(and fuel) in the range you want a little more selectively than the GCC does. It's still not a great solution, since it screws with the airflow signal to fool the ECU, just like the VPC/GCC combo. But you might find that the 3D adjustments on it give you the range you need to do your tuning. Switching to DSMLink would definitely do the trick for you, and would give you the ability to adjust fuel and timing independently(among the many other pluses it has) so that you can dial your AF ratio in, then adjust the timing however you want, and not have to worry about the fuel tuning getting messed up.

If you sold off the GCC, these other options wouldnt be too expensive either. They would probably be cheaper than the MSD option.

What makes you certain that your spool issue is a problem with timing? I don't see your exhaust listed on your mod list, what do you have?

Brad

 

[Mike 99GSX]

I have a full Buschur 3" exhaust. I don't have any leeks. This was never a problem until I switched turbos. I have had the turbo off 2 or 3 times since so I know everything is and was tight each time before I took it off. I checked the SFP manifold for cracks and don't see any. I also swapped back 550 injectors because someone said it could be too low duty cycle with the 660s but I still had the crazy high timing. I really don't know at this point what it could be. If I abandon the VPC, I would just go to the EMS but I was hoping to make this work first. Any thoughts?

 

[brads]

When you say it was never a problem until you switched turbos, do you mean that your timing was lower during spoolup with your previous turbo? Or do you mean it didn't take as long to spool up? Were you running the HKS EVC-EZ with the previous turbo set up? FWIW, I noticed my 50 trim internally gated hybrid spooled slowly between shifts with a Profec B. Playing around with a manual controller, got it spooling MUCH quicker. I think the EVC-EZ is supposed to be pretty slow in terms of boost response.

Brad

 

[Mike 99GSX]

Originally posted by brads
When you say it was never a problem until you switched turbos, do you mean that your timing was lower during spoolup with your previous turbo? Or do you mean it didn't take as long to spool up? Were you running the HKS EVC-EZ with the previous turbo set up? FWIW, I noticed my 50 trim internally gated hybrid spooled slowly between shifts with a Profec B. Playing around with a manual controller, got it spooling MUCH quicker. I think the EVC-EZ is supposed to be pretty slow in terms of boost response.

Brad

Yes my timing used to immediately drop down to like 9 and work its way up when I had the 16g. I've already switched from the EVC-EZ to a manual but it didn't make a difference.(I forgot to update the profile). The other changes were the SFP manifold, Tial Wastegate, 660s, and the Dejon intake pipe for the turbo. I thought it might have been the pipe tonight because it never really seated perfect with the turbo so there would be a little pocket between the coupler. I recut the pipe today and it snugs up perfect metal on metal now but it didn't fix the problem. I'm wondering now if maybe the SFP manifold has a crack in it and I just can't see it with the ceramic coating. I'm not exactly sure if it did it from day one because I originally had a .48 housing and it spooled a good bit quicker. I should probably take the manifold off and look at it real closely.

 

[brads]

With the VPC setup, the intake pipe leak shouldnt make much of a difference. Now if you have a leak in the intercooler piping or intake manifold that is allowing the air to escape after the turbo, that would cause more lag.

The big timing difference that you are seeing is a symptom of the slow spool, not the cause. There has to be some other reason for it. Have you double checked the wastegate setup? How much quicker spooling was the .48 housing? Are you sure the one you got was .63?

Brad

 

[Mike 99GSX]

Originally posted by brads
With the VPC setup, the intake pipe leak shouldnt make much of a difference. Now if you have a leak in the intercooler piping or intake manifold that is allowing the air to escape after the turbo, that would cause more lag.

The big timing difference that you are seeing is a symptom of the slow spool, not the cause. There has to be some other reason for it. Have you double checked the wastegate setup? How much quicker spooling was the .48 housing? Are you sure the one you got was .63?

Brad

I would guess the .48 was about 800 RPM faster than the .63. It is definately a .63. I don't have any significant boost leeks. The 1g BOV is leeking after about 22PSI but I don't think that would have anything to do with the slow spool right because the spool up isn't happening at that high of PSI yet. It holds boost fine during a boost leek test until I turn the compressor up past 20 PSI. I was thinking of hooking up a hose from the compressor outlet directly to the wastegate and bypassing the boost controller. I should only see the spring rate of the wastegate as far as boost goes but that might tell me something.

 

[44pirate]

Where did the .48 ar begin to spool as opposed to the .63ar.
My 50trim starts to spool at 2400 and at 3400 is at 21psi.

 

[Mike 99GSX]

Originally posted by 44pirate
Where did the .48 ar begin to spool as opposed to the .63ar.
My 50trim starts to spool at 2400 and at 3400 is at 21psi.

I don't exactly remember because I took it off fairly soon after putting it on. I'm guessing you have a .48 with those numbers right? I think the test of bypassing the boost controller and going directly from the compressor housing to the wastegate might tell me something. I'm going to try that tomorrow. If that works, then I'll rehook up the manual and turn down the boost and work my way back up. I was also going to try taking my pressure source for the boost controller from my compressor housing insteaad of the BOV line and see if that helps.

 

[44pirate]

No I have a .63 ar. When I ran the stock mas it would start to spool at 3000 and hit full boost at 4000 which was 21psi. Since I installed the MAF translator it starts spool at 2400 and by 3400 I get 21psi.

 

[Mike 99GSX]

Originally posted by 44pirate
No I have a .63 ar. When I ran the stock mas it would start to spool at 3000 and hit full boost at 4000 which was 21psi. Since I installed the MAF translator it starts spool at 2400 and by 3400 I get 21psi.

Well I guess I'm jealous then. Believe me if I could just get full boost at 4000, I'd be happy

 

[Mike 99GSX]

Well I tried a few more things today. I ran my pressure source to my manual boost controller from my compressor housing instead of the BOV line. It seems like spool is about 200 RPM better this way. It seems like there's mixed opinions on which way is better when I searched so I'm just going to leave it this way for now. I'm getting full boost now at about 4600RPM which still isn't good. My only guess at this point is an exhaust leek. I don't have the energy to take the manifold off right now but I think I'm going to have a hard time seeing cracks anyway with the black ceramic coating on there. I don't want to bad mouthh an SFP manifold because I have no idea if this is the problem. Put it this way, I can't see anything visibly wrong on the top of the manifold. Maybe there's a crack on the underside where I can't see? I don't here anything. I'm really stretching at this point.