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View Full Version : Slow Spool Up, Why?



Captain Chaos
08-20-2006, 04:07 PM
I have taken the boost control chore away from the computer and installed a manual boost controller on my Horizon. It seems to take forever to spool up. The setup is an 87 T-II with a Garrett, 2pc intake, an MP computer, 2.5 S/V, 3" exhaust no cat or muffler, and a GLHS rad I/C setup. Would it be terribly bad to run a hose from the turbo directly to the TB to see if it spools faster to eliminate any boost leaks in the piping/intercooler? Once it gets to 15 it feels great but then it seems like its time to shift.

turbovanmanČ
08-20-2006, 05:11 PM
Cam timing, sounds like the cam is retarded one tooth. Mine and others act the same way, its soggy down low and goes well up top.

Captain Chaos
08-20-2006, 08:40 PM
Cam timing, sounds like the cam is retarded one tooth. Mine and others act the same way, its soggy down low and goes well up top.
I'll double check that thanks. Standing on the passenger side of the car in front of the timing gears I should move the came to the clockwise one tooth correct?

turbovanmanČ
08-20-2006, 08:52 PM
I'll double check that thanks. Standing on the passenger side of the car in front of the timing gears I should move the came to the clockwise one tooth correct?

Correct, one tooth forward or clockwise. :D

Captain Chaos
08-20-2006, 09:15 PM
I'm going to check it out tomorrow. Always overlooking the obvious. Thanks again.

Garret
08-21-2006, 02:48 AM
How do you have the boost controller routed? where is the pressure signal coming from? and are you sure the boost controller is setup right?

Captain Chaos
08-21-2006, 07:38 AM
How do you have the boost controller routed? where is the pressure signal coming from? and are you sure the boost controller is setup right?
Its routed from a 4 port vacuum source on the intake to the MBC and from there to the WG. Yes, I have the vacuum hose from the intake going to the "IN" on the MBC and to the WG from the "OUT".:thumb:

Dave
08-21-2006, 09:56 AM
Try the signal from the compressor housing if you can. I know some Garretts didn't come with a barb on the compressor housing.

turbovanmanČ
08-21-2006, 12:29 PM
Its routed from a 4 port vacuum source on the intake to the MBC and from there to the WG. Yes, I have the vacuum hose from the intake going to the "IN" on the MBC and to the WG from the "OUT".:thumb:

Well, ahem, if you do it the other way, bad things happen, ask me how I know, :(

Captain Chaos
08-21-2006, 01:19 PM
Well, ahem, if you do it the other way, bad things happen, ask me how I know, :(
Let me guess the pressure from the intake spools the turbo backwards and causes cooler exhaust gases to be recirculated into the intake tract?:D

turbovanmanČ
08-21-2006, 01:30 PM
Let me guess the pressure from the intake spools the turbo backwards and causes cooler exhaust gases to be recirculated into the intake tract?:D

Exactly, :nod:

Captain Chaos
08-21-2006, 10:39 PM
Well timing belt looks right. I put the mark on the flywheel to 0, dist drive"line going left to right, and the cam cap lines splittting the holes in the cam gearwith the small hole at 12 o'clock. Means it should be good correct? I tried using the small vacuum port on the TB which didn't seem to make any difference. First gear only gets about 10 psi before redline, 2nd gets 15 about 4500, and 3rd gets 15-16about 4000. The turbo does have a .63 AR exhaust housing on it, if that matters. Maybe it is what it is. I do have a large can adjustable wastegate on there, could it be set too loose?

contraption22
08-21-2006, 10:50 PM
Try tightening up the wastegate arm. Check to make sure there are no boost leaks. What are all the specs of the turbo?

Captain Chaos
08-21-2006, 11:05 PM
Try tightening up the wastegate arm. Check to make sure there are no boost leaks. What are all the specs of the turbo?
Its one noone seemed to like in another thread. T3/T04B super 46 trim with the .63 ar exhaust housing and std exhaust wheel. It seemed like the closest thing to a super 60 that was my original thought for an upgrade. I felt like a 50 trim would have been too much at this point. And I'm not doubting the turbo, I'm sure there are adjustments that are needed, just looking for ideas to try. It feels like the car is "wanting" to go faster but something is holding it back. plugs 3 and 4 look like they have been sprayed with brown primer and 1 and 2 are pale skin color, so really unsure whether to add fuel or take some out. Unfortunately the wideband isn't installed yet and I don't have an EGT gauge.

As a side note the car always felt laggy, even with the stock garrett on it from a roll. From a stop it would spool relatively quick, but to downshift and floor it it would take awhile to build boost. 15 psi definately feels better now than before, but would like to feel it sooner.:thumb:

turbovanmanČ
08-22-2006, 12:03 AM
Is the .63 housing for a standard wheel and not a stage 2 or stage 3 wheel. Advance the cam one tooth forward and see what happens.

Captain Chaos
08-22-2006, 08:03 AM
Is the .63 housing for a standard wheel and not a stage 2 or stage 3 wheel. Advance the cam one tooth forward and see what happens.
Yes its a standard wheel. I'll try one, what happens with two teeth advanced?

turbovanmanČ
08-22-2006, 12:18 PM
Yes its a standard wheel. I'll try one, what happens with two teeth advanced?


Two teeth is too much!

Captain Chaos
08-23-2006, 09:43 PM
I guess low compression would cause it as well huh? All the cylinders are the same but all are equally low. Guess I'll try a re-ring see if compression comes up. The motor was a fresh motor with roughly 2000 miles on it.:banghead: :faint:

Oh yeah tried the cam tooth theory and there was no change.

turbovanmanČ
08-24-2006, 12:24 AM
I guess low compression would cause it as well huh? All the cylinders are the same but all are equally low. Guess I'll try a re-ring see if compression comes up. The motor was a fresh motor with roughly 2000 miles on it.:banghead: :faint:

Oh yeah tried the cam tooth theory and there was no change.


Whats the compression? what cam are you running?

Captain Chaos
08-24-2006, 07:23 AM
Whats the compression? what cam are you running?
Compression was an even 110 across the 4 cylinders. Its a 91 turbo roller cam I had from another car.

iniviate
08-24-2006, 09:39 AM
heh... i wouldn't rebuild that. :)

what timing pullies are you using?

a round tooth cam installed with a square tooth pulley will be something like 4 degress off. i forget which way.

Captain Chaos
08-24-2006, 09:44 AM
heh... i wouldn't rebuild that. :)

what timing pullies are you using?

a round tooth cam installed with a square tooth pulley will be something like 4 degress off. i forget which way.
Its a square tooth pulley. I've never heard that. HMMM You don't think 110 psi is too low?

iniviate
08-24-2006, 09:52 AM
HMMM You don't think 110 psi is too low?

i seem to remember most of my motors coming in around 120psi. if they're all even, i wouldnt worry about it.

i'll look around and see if i can find some info on the cams.

iniviate
08-24-2006, 09:59 AM
here's one where they talk about it a little on page 2.

http://www.turbo-mopar.com/forums/showthread.php?t=1740&page=2&highlight=roller+square+tooth

that's all i feel like looking for though, you have a search button too. :)

Captain Chaos
08-24-2006, 10:12 AM
I'll search into it more. But the car had been running strong with the stock T-II turbo until a month or so ago. It would pull strong from a stop. From a roll seemed to take a second to get going even when down shifting. Now has no low end but after about 4000 seems to pull fairly strong at 18psi. Still not impressed though.

Thanks for the help.

Captain Chaos
08-24-2006, 10:23 AM
Based on this thread if what you say is correct about the 4 degrees then its only a half tooth either way.
http://www.turbo-mopar.com/forums/showthread.php?t=4880&highlight=square+tooth

Keito
08-24-2006, 11:47 AM
Installing a round tooth cam using a square tooth gear will retard the timing
4 degrees.
Don't ask me why I know that, I learned the hard way.

Captain Chaos
08-24-2006, 01:43 PM
Installing a round tooth cam using a square tooth gear will retard the timing
4 degrees.
Don't ask me why I know that, I learned the hard way.
Then I can advance 2 teeth.:eyebrows:

turbovanmanČ
08-24-2006, 04:29 PM
Then I can advance 2 teeth.:eyebrows:

Each tooth is 9 deg's.

110 is fine, but a fresh engine should be around 140-150 psi.

Captain Chaos
08-24-2006, 04:41 PM
Each tooth is 9 deg's.

a fresh engine should be around 140-150 psi.
Well thats the problem, this motor *might* have 2000 miles on it with the first 700 never seeing boost over 7 psi. I found out my knock sensor is broken, but that only affects timing correct?

ssheen
08-24-2006, 07:07 PM
did you have the throttle open and all plugs out when you did the compression test?

Captain Chaos
08-24-2006, 08:47 PM
did you have the throttle open and all plugs out when you did the compression test?
Um no and no.:o Should I have?

cordes
08-24-2006, 08:50 PM
Um no and no.:o Should I have?

Most certainly. Glad you did not pull the thing apart yet.

Could your knock sensor be pulling timing since it is broken? I don't have any experience driving one with a broken one so I would not know. If it is pulling timing it will be really slow for sure.

Captain Chaos
08-24-2006, 08:57 PM
Most certainly. Glad you did not pull the thing apart yet.

Could your knock sensor be pulling timing since it is broken? I don't have any experience driving one with a broken one so I would not know. If it is pulling timing it will be really slow for sure.
Well I'll run out there and pull the plugs and check it. I drove it when I first got it running originally w/o the knock sensor plugged up because it was broken.

contraption22
08-24-2006, 09:08 PM
The knock sensor will not pull timing. The computer will pull timing out if it gets input from the knock sensor.

Captain Chaos
08-24-2006, 09:20 PM
New cylinder readings:
#1 #2 #3 #4
145 145 140 139
:clap2: You guys are awesome. Something I never knew. Makes me even more nervous about the fact that I assembled this motor by myself.:o

Captain Chaos
08-24-2006, 09:21 PM
The knock sensor will not pull timing. The computer will pull timing out if it gets input from the knock sensor.
Gotcha thanks for clearing that up for me.:thumb:

contraption22
08-24-2006, 10:55 PM
Sean, check your ignition timing.

Captain Chaos
08-25-2006, 07:49 AM
Sean, check your ignition timing.
Mike its set at 14* right now.

contraption22
08-25-2006, 10:46 AM
Mike its set at 14* right now.


Just for experiment's sake... try retarding it to about 10*.

Captain Chaos
08-25-2006, 10:58 AM
Just for experiment's sake... try retarding it to about 10*.
I'll try it. Can't hurt. When it rains it pours. I have charging issues now. So I'm replacing the alternator and PM today when the rain slacks up.

contraption22
08-25-2006, 11:40 AM
I have a funny feeling it will work for you.

Captain Chaos
08-25-2006, 08:06 PM
I have a funny feeling it will work for you.
First off thanks for everyones help. Mike it definately feels a bit smoother/crisper. The car just doesn't feel like its pulling very hard at any boost pressure until like 15-19. But by that time it feels like its out of breath. I just don't think its entirely the new turbos fault because the stocker the same thing from a stop. From a roll at about 3500 RPM's it seems to "try" to move out. Cars all out of breath about 5000.It used to pull until like 5500. Could a weak coil(stock), or bad plugs(RN12YC's gapped @.035) be the culprit. And don't know if this has any bearing on the problem but when downshifting I get a good deal of blue smoke. Thought it might be from oil puddled in the exhaust but it should smoke constantly.

iniviate
08-25-2006, 10:52 PM
my 8 valve stuff really liked an MSD past about 18psi....

Captain Chaos
08-25-2006, 11:00 PM
my 8 valve stuff really liked an MSD past about 18psi....
Well I don't know about an MSD box, but I just pulled the MSD coil off of my old Plymouth and stuck it on the "new" Plymouth and dropped the fuel pressure down a little, from 52 to 48 psi. Thats using the CSX stg II computer and +20's. It feels about 50% better but thats as far as I want to go with the fp until I have a wideband on the car.