Custom Cal Vacuum Lines?

[stealthydave]

Hey everyone, my Daytona is almost ready and I'm stuck on getting the vacuum lines right.
Heres the set-up.
88 Daytona Shelby Z
2.5 (.040 over) 91 common block
+40 injectors
G-head
Acufab adj FPR
3 Bar MAP
K&N air filter
2.5" side exit exhaust (Catco cat, dynomax bullet)
Custom cal SMEC (set for 18 lbs)

I've tried a few variations on the setup and I can't seem to get more than 8 lbs. ??

Does anyone have any suggestions?
I'm really hoping to run the car at the Spring Fling next weekend.

Thanks in advance!
D

[ShelGame]

What custom cal are you using? How are you plumbing the vac lines?

I'm going to assume you have a 2.5 T1 based cal (is it based on one of mine?). If so, you need to plumb the WG lines exactly like the '89 T1 diagram. The T1 boost control works a little differently from the T2 WG control.

It needs to be plumbed like this:

Manifold/turbo ---- WG Can ----- Solenoid

NOT like this:

Manifold ---- Solenoid ---- WG Can

Also, if you are using the T2 style solenoids (2 ports with a "L" shape on the top, single port on the bottom), you need to cap the top port; the WG line should go to the middle port; and the bottom port should be vented to atmosphere. Stock had a restrictor in between the manifold and the WG can, but I think it should work even without it.

[stealthydave]

Matt Wright set up the cal for me.

First I set up the lines following the stock T2 diagram.
That didn't work.
Then I tried to follow the stock 2.5 T1, that didn't work either. (But I can only assume that I did something wrong.)

I will apply your suggestions when I get the chance, probably this weekend.
Thanks!
D

[stealthydave]

Oh, heres something that had me stumped also...
(forgive my ignorance)
According to the 89 T1 diagram, (which I assume is a Mitsu), the turbo has 2 lines running out of it, where-as the (88 T2) Garrett only has 1.

How is this addressed?

[ShelGame]

Oh, heres something that had me stumped also...
(forgive my ignorance)
According to the 89 T1 diagram, (which I assume is a Mitsu), the turbo has 2 lines running out of it, where-as the (88 T2) Garrett only has 1.

How is this addressed?

You can try to go direct to the manifold with the WG line. But, the plumbing gets a little cumbersome then. And, the boost signal isn't exactly the same due to the throttle body. in boost it should be close, but with the throttle closed, it's different. I'm not sure how this would affect the WG control.

It might be better to simply make a "T" of the single Garret fitting - 1 for the WG the other to the cruise(?).

I think I know how to convert the T1 code to T2 style WG control. But, I haven't been able to test it yet. And, I don't know that there'd be any advantage...

[stealthydave]

cool.
thanks.
I'll do some testing this weekend.
take care

[stealthydave]

Okay, I just getting deeper and deeper.
First of all the custum cal issue appears to be on it's way to be taken care of. In the mean time I have re-installed the stock smec just for the sake of driving the car. but oddly enough I'm only getting 7 lbs. ??? (I had set the lines back to the stock 88 T2 setup.) The 3 bar map is still installed, would that have any affect on it?
Thanks!

[GLHSKEN]

Dave,
Don't mix maps and cals... bad idea for the pistons. Just drive over this weekend and I'll take a look at it.

[stealthydave]

well it's only been like that for a couple days, and I certainly haven't pushed it by any stretch of the imagination (too paranoid). As it turns out I, have the new cal chip ready to install.

This new chip requires the stock vacuum set-up, therefore I put it back that way and dropped in the stock smec for the time being, just to see what would happen.

I was just curious as to why I was only getting 7 lbs when everything was stock, except for the map. ??


I just might give you a call this weekend. Got a few things to do, but it would be good to drop by and visit.
Thanks!

[GLHNSLHT2]

Rob it would be awesome if you could put the T2 control routines into your cal. I'll test it! I can't get less than 16-18psi no matter what the scanner is calling for. I've gone as far as putting an 88 T1 wastegate solenoid in place of the 87 T2 solenoid. My next step is to wire up 89+ solenoids. It's driving me batty. I'd like lower boost some times

[ShelGame]

well it's only been like that for a couple days, and I certainly haven't pushed it by any stretch of the imagination (too paranoid). As it turns out I, have the new cal chip ready to install.

This new chip requires the stock vacuum set-up, therefore I put it back that way and dropped in the stock smec for the time being, just to see what would happen.

I was just curious as to why I was only getting 7 lbs when everything was stock, except for the map. ??

Do you have the restrictor in place between the WG can and the pressure source? I found out this weekend that's it is indeed needed. I have the computer setup for 14psi, but was only getting 5psi boost, creeping up to maybe 9-10, on a mitsu turbo (they usually spool to 14psi instantly). I didn't put the restrictor in when I re-built the vacuum lines...

It's in there now.

[ShelGame]

Rob it would be awesome if you could put the T2 control routines into your cal. I'll test it! I can't get less than 16-18psi no matter what the scanner is calling for. I've gone as far as putting an 88 T1 wastegate solenoid in place of the 87 T2 solenoid. My next step is to wire up 89+ solenoids. It's driving me batty. I'd like lower boost some times

I've looked at it, and I just don't see the advantage for the amount of work it would be.

[stealthydave]

Do you have the restrictor in place between the WG can and the pressure source? I found out this weekend that's it is indeed needed. I have the computer setup for 14psi, but was only getting 5psi boost, creeping up to maybe 9-10, on a mitsu turbo (they usually spool to 14psi instantly). I didn't put the restrictor in when I re-built the vacuum lines...

It's in there now.

I've made some progress but I'm still only hitting 7 pounds. (Apparently my speed sensor was going bad and that was causing lots of issues.)
anyway...
Yes I do have a restrictor, this is how it is set up right now...
I have a line running from the manifold/source to the solenoid, with a line from the wastegate can 'T'd in. The restrictor is between the wastegate can and the T.

[ShelGame]

I've made some progress but I'm still only hitting 7 pounds. (Apparently my speed sensor was going bad and that was causing lots of issues.)
anyway...
Yes I do have a restrictor, this is how it is set up right now...
I have a line running from the manifold/source to the solenoid, with a line from the wastegate can 'T'd in. The restrictor is between the wastegate can and the T.

The routing sounds right.

How big is the hole in the restrictor? The first one I tried was ~0.04". It let me get up to 12psi, but no higher. So, I put in a 0.02" restrictor, and I can get 18psi, no problem.

If yours is 0.04" or bigger, maybe try a smaller one.

[stealthydave]

I'll have to double check tonight. I don't recall off hand. Thanks, I'll let you know.

[ShelGame]

Alternately, if the restrictor seems OK, it could be a bad WG can...

[stealthydave]

the kicker is, during a couple of the set ups I tried last week, I was hitting boost as high as 19 lbs, but I was experiencing a constant annoying cutout. (which turned out to be my speed sensor) so I know that the system is capable of reaching the desired boost, I just don't have the experience and/or knowledge to tackle this easily.
By the way if I hadn't mentioned it...
Thanks for your help!!

Anytime I work on my cars I always learn something new.

[stealthydave]

The routing sounds right.

How big is the hole in the restrictor? The first one I tried was ~0.04". It let me get up to 12psi, but no higher. So, I put in a 0.02" restrictor, and I can get 18psi, no problem.

If yours is 0.04" or bigger, maybe try a smaller one.

Okay good news.
I went back to an earlier post of yours where you told me to cap off the top barb of the solenoid. (The cap was removed during all of the different tests) I put the cap back on, I put in a second restrictor in the line, and then I double checked all of the IC hose clamps and made sure everything was tight. (A couple needed to be a tightened up a little)
Took it for a spin...
And I got 14 lbs! it felt goooood!
It's getting there.

Oh, and I checked the size of the restrictor, the package reads 3/16" (4.76 mm). Its the only one that Pep Boys had. So, I guess I should try NAPA to see if they have anything smaller. ???

Thanks!!

[ShelGame]

Okay good news.
I went back to an earlier post of yours where you told me to cap off the top barb of the solenoid. (The cap was removed during all of the different tests) I put the cap back on, I put in a second restrictor in the line, and then I double checked all of the IC hose clamps and made sure everything was tight. (A couple needed to be a tightened up a little)
Took it for a spin...
And I got 14 lbs! it felt goooood!
It's getting there.

Good news, for sure.

Oh, and I checked the size of the restrictor, the package reads 3/16" (4.76 mm). Its the only one that Pep Boys had. So, I guess I should try NAPA to see if they have anything smaller. ???

Thanks!!

3/16" is the size of the barb, not the orifice. My package said the same thing. I guestimated the size at ~0.04". That one came from Murray's (local MI chain). I bought another one from CarQuest, the package also said 3/16", but the hole was smaller - I guestimated about 0.02". Another way to compare them is to blow through them. Use the one that flows the least...

[stealthydave]

Good news everyone!
Between the help here, the guys at the OVC Spring Fling and a ton of input from Matt Wright, I'm hitting 19 lbs now!

It was a combination of using smaller lines, 2 restrictors, as well as an IC connection that was venting off pressure. oops.

Thanks for all of the help!!