Slow Spool and bad boost recovery

[biglady112]

Compression is not his problem. I live at altitude and mine is 95-100psi across the board and my car runs just fine.

 

[19BLACKGST98]

Springs, retainers and cam degreeing helped spool and boost recovery but somthings still wrong. Will be pulling the head soon.

 

[19BLACKGST98]

The car is taking 2.6 sec to get from 70 - 90 MPH. I am completely lost.

 

[MY1GDSM]

Have you wired in your clutch switch for NLTS yet?

 

[19BLACKGST98]

No I will probably do that tomorrow along with a few other things. I guess Ill just wire it up and tap it since I don't have anyway to solder it at the moment.

I'm going to borrow another 95 eprom ecu and see if that does anything.
I'm going to disconnect ABS and see if that makes a difference and I'm going to check the tranny fluid for metal.

At this point I'm just going to check random things that probably have nothing to do with the problem.

Edit: I'm also thinking about ditching the Maf/MafT and hooking up my SD and boost by gear before I find the problem just in case it does anything.

Here is my last log. We lowered timing way down and try to get as much air into the system as possible on pump gas alone, the boost gauge was reading 27psi.

We are simply trying to find the issue not really worried about fine tuning so much.

***I noticed in all of my logs that during my pulls I am usually around the 2.6 load range...is that normal? Both logs were on pretty flat surfaces?***

 

[MY1GDSM]

Definitely get at least a map sensor hooked if you can, Even if you don't get it running on SD. I'm curios to see a log with the actual boost being logged as I said before...

 

[19BLACKGST98]

I have the omni 4 bar map. Do I still install it just like this?
gm3barinstall [ECMTuning - wiki]

 

[MY1GDSM]

You can wire in the Map sensor to any open ECU input See here... the MDP input will work fine...

But, I seem to remember you saying that you had a ECMLink GM Maf cable in you other thread? if so the Cable has break outs that are run through buffers an that would probably be the easiest route since you could continue to run the GM Maf an since it's already dialed in with it.

An you won't have to worry about doing This<-- click or or getting a Buffer if you don't run the Map to the MDP since they are built in like when running a sensor to the Baro input with out the cable...

 

[19BLACKGST98]

You can wire in the Map sensor to any open ECU input See here... the MDP input will work fine...

But, I seem to remember you saying that you had a ECMLink GM Maf cable in you other thread? if so the Cable has break outs that are run through buffers an that would probably be the easiest route since you could continue to run the GM Maf an since it's already dialed in with it.

An you won't have to worry about doing This<-- click or or getting a Buffer if you don't run the Map to the MDP since they are built in like when running a sensor to the Baro input with out the cable...

I didn't buy the ECMlink GM Maf cable because I bought everything to run SD. So I will look into the other stuff you posted. I am confused with the instructions I posted above. After you tap into the wires leading to the MDP do you not plug it back in to its original spot?

 

[MY1GDSM]

You are going to be using the Ground, power an Signal wires of the MDP to run the MAp sensor an No longer have a MDP (so your not really taping into it) you can of cource disable the ETC check for the MDP in link afterwards...

So, What exactly did you buy from Ecmlink?

 

[19BLACKGST98]

So, What exactly did you buy from Ecmlink?

Full ECMLink V3, SD bundle, SD PNP Cable and the Boost by Gear solenoid.

I just got off the phone with one of the guys helping me with the car. He said if I put the Map sensor in now (instead of when I convert to SD) that I will have to do some wiring that I wouldn't otherwise have to do. He said if I wait then it will just plug in place of the Maf. He also said that NLTS isn't going to change anything on the logs because the lack of acceleration is the problem.

Should I start another thread strictly about acceleration at this point? The spool and boost recover has improved (its tolerable for a 70lb min turbo) and now the car is just really slow accelerating like I have a 1000lbs extra in the car or something.

 

[MY1GDSM]

Are you getting This map sensor from them? I don't see the Omni 4 bar on the site...

I guess if you call 3 wire hooking up 3 wires "doing some wiring that I wouldn't otherwise have to do" that's true but you can also switch over to SD while still running the GM maf... whitch can make building a VE map easier if you haven't Before.
See Here...

I guess it really depends what parts you have laying around an if your getting a GM style map sensor you can pick up from a million cars in junk yards the harness to hardwire it into the MDP...


As far as the NLTS not doing anything WTF really?

 

[19BLACKGST98]

Are you getting This map sensor from them? I don't see the Omni 4 bar on the site... It must be that one...I could have swore it use to say something like Omni before it when I bought it?
EDIT: Omnipower 4-bar MAP-MITS-4BR or MAP-GM-4BR (4 bar)

I guess if you call 3 wire hooking up 3 wires "doing some wiring that I wouldn't otherwise have to do" that's true but you can also switch over to SD while still running the GM maf... whitch can make building a VE map easier if you haven't Before.
See Here...
I guess ill still hook it up. So earlier you were saying to tap into those wire with the MDP connector on the end of it but not to plug it back into its original spot? So do I just zip tie it to something (the connector I mean so its not just flopping around)? Also Ive never heard of Vampire taps...are those just the little claps that cut into the wire cover to make a connection and are they available at any auto parts store?

I guess it really depends what parts you have laying around an if your getting a GM style map sensor you can pick up from a million cars in junk yards the harness to hardwire it into the MDP... I have the map sensor you linked above from ecmlink already


As far as the NLTS not doing anything WTF really?
I know it would improve track time, he was referring to actual acceleration...even after the other things improved the car still always took around 2.6 sec to get from 70 to 90 MPH

What all would affect the acceleration at those speeds?
What I can think of right now is a lot of extra weight, something draging, something not going smoothly in the tranny, maybe something in the ECU isn't working right or ABS coming on from reading a faulty signal or somthing?

 

[MY1GDSM]

I'll try to help with you other questions later.
But I'm logging off an walking out the door right now...

I guess ill still hook it up. So earlier you were saying to tap into those wire with the MDP connector on the end of it but not to plug it back into its original spot? Yes

So do I just zip tie it to something (the connector I mean so its not just flopping around)? If you feel it's necessary I guess

Also Ive never heard of Vampire taps...are those just the little claps that cut into the wire cover to make a connection and are they available at any auto parts store? Yes

You just can cut the harness off an wire(solder) it directly that would be the most Ideal method an what I would do... if you looking for something more temp. since you have the plug in play harness(waste of money in my eyes(unless you plan on going back to a Maf) the way you described would work as a temporary solution though no Ideal.

 

[19BLACKGST98]

I'll try to help with you other questions later.
But I'm logging off an walking out the door right now...



You just can cut the harness off an wire(solder) it directly that would be the most Ideal method an what I would do... if you looking for something more temp. since you have the plug in play harness(waste of money in my eyes(unless you plan on going back to a Maf) the way you described would work as a temporary solution though no Ideal.

Ok thanks for the help.

 

[keltalon]

Sounds like a pre-turbo exhaust leak. Check to make sure your exhaust manifold gasket is good, and your manifold to turbo gasket is good. I'm having the same problem with my 16g and i doesn't hit full boost til about 4100 rpm. So I started up the car and ran my hand around the mating surface of the manifold and turbo, and sure enough I could feel a huge leak in the back. Hope this helps.

I have been following this tread because I was having the exact same issue. And had tried everything the OP put in post #1. Today I decided to breakdown and pull my whole turbo off base on the post ^^^ and I am glad I did because I solved my slow spool and low boost and bad boost recovery issue here are some pics of what I found. The car is fast but not making the numbers that others are making with similar size turbo even the honda guys had me by a couple hundred horsepower I was reading a tread yesterday of a fellow dsmer putting down 671 awhp with a 6262 ball bearing unit I knew that something was wrong. I have a 6465 billet series ball bearing unit rated at 81lbs/min I should be putting down similar numbers. So I decided to rip the turbo manifold off the car. I had a bad leak where the turbo and manifold met as well as a leak on runners 3 and 4 I could not hear the leak because my car is so loud. I disconnected my wastgate and still could not make over 29lbs of boost. My turbo was seeing 1lbs of boost around 4000 rpm and 29lbs around 6500 rpm. I ordered new gaskets today. I also am having a machine shop surface the manifold the turbo housing and the turbo flange on the manifold to ensure everything is straight when she goes back together. Hope this help OP!

 

[19BLACKGST98]

I plugged up my exhaust from the back to check for leaks and I couldn't find any. I will go ahead and pull it all apart again just in case. Thanks for the post.

Did you just order OEM gaskets? If not what kind of gaskets did you order and where did you order them from?

 

[keltalon]

I plugged up my exhaust from the back to check for leaks and I couldn't find any. I will go ahead and pull it all apart again just in case. Thanks for the post.

Did you just order OEM gaskets? If not what kind of gaskets did you order and where did you order them from?

FFWD Connection - Race Injuns That Will Freeze Your Brain

 

[19BLACKGST98]

FFWD Connection - Race Injuns That Will Freeze Your Brain

I was wondering if that is what you went with. I used the copper exhaust manifold gasket from them before (a long long time ago) and it worked out fine. I dont think they sold all of these back then though. I will go ahead and change them all out just in case. Thanks again.

 

[keltalon]

I was wondering if that is what you went with. I used the copper exhaust manifold gasket from them before (a long long time ago) and it worked out fine. I dont think they sold all of these back then though. I will go ahead and change them all out just in case. Thanks again.

I also picked up a tube of this stuff just for the insurance read here.

Extra thick turbo/manifold gasket?

 

[keltalon]

Okay I will be in business as soon as my other stuff come in. I picked up manifold from maching shop today.

 

[19BLACKGST98]

For some reason I decided not to sell this never running correctly money pit. Anyone have any new Ideas this year?

 

[turboglenn]

If your spool has improved but it's still feeling like a dog i would say it's the timing i'mseeing in those logs. I know that to run high boost timing has to be backed off on pump gas but there's a point where you need to be flowing a LOT of air to make that low timing not be killing your power. PUt it this way, in the 450 - 500hp range where iroughly sit now, if my timing is locked at 10* BTDC (feature used in my ECU to set the base timing) and if itake off driving on that the car feels dead slow in comparison tothe normal timing map with only 6-8* more timing in it.

IN this HP range i'm still dependant on timing to make good power from the airflow, and in my experiences (meaning i can't say it's a scientific fact) you need to be moving enough air for about 650-700hp to get awy with running timing that's maxed out at 7* BTDC.. the only way i can explain it is that atthis range i'mstill compressing and using the air and fuel for the max available power ican extract from what i'mgiven, but when you get to the levels where timing starts to have less of an effect it's more like you are just trying to blow the air in one side and out the other notreally too concerned with trapping and compressing it, but just getting it in and out as fast as possible.. Like i said this seemsto be from myexperience about the 600+ mark that timing can be dialed back that low and not be notably slower compared to a curve that starts at 12* and maxes out at 17* or so BTDC (It's a huge loss that i can feel going from the 12-17* curve to having just a flat 10* across the WOT board, I could notimagine only running 7* for airflow supporting less than 700whp)

just my thoughts on the power part of the equation, glad you got the spool figured out though

I would be willing to bet that you'd make more power or at least go faster with less boost and a timing curve that never is less than 14* from 4500 RPM and up, and advancing it to at least 16* or so and running about 21-22psi on pump gas (but these are just thoughts based on what i've seen,tuned and dealt with)

 

[19BLACKGST98]

We have tried so many diffrent variations of boost and timing....we have also adjusted the cam gears all over the place and all of the adjustments still have the car running very slow acceleration times between 70-90 and 80-100mph. Before i gave up on the car last time we changed the cams and went to behive Springs. Then the rest of the day and till about 2am the next day we were adjusting the tune to try to speed up the acceleration. We ended up just leaving it at 7* timing and 27 psi (on pump only) because we couldnt figure it Out.

Thanks for the reply glen...all suggestions are welcomed.

 

[fosforito95]

Okay I will be in business as soon as my other stuff come in. I picked up manifold from maching shop today.

Ketalon did this solve your particular problem with spool and recovery??