Question for those with aftermarket boost gauges

[z284pwr]

I'm curious, those of you TGP/LG5 setup guys that have aftermarket boost gauges, what kind of boost do you actually get?

 

I finally got my gauges in and actually got on it today, I was suprised, the poor little turbo can only get to 7.5 PSI? I'm sure it wasn't even that high at top end, it definitely doesn't like high RPMs

 

Oh yeah, and does anyone else have an EGT gauge other than Davis? I'm curious to see how much higher EGTs I have that a stock engine.

[TGPilot]

I see 14.0 - 14.3 PSI constantly at WOT on a T-25 with about 170,000 miles on it.

 

Are you running an aftermarket boost controller or the stock WasteGate Actuator circuit?

 

If stock WGA are you running a stock chip? Stock chip = 7 - 8psi

 

If you are aftermarket boost controller or raised boost chip and you do not see more than 7 - 8psi then most likely the wastegate diaphram spring is week and allowing the wastegate to open due to backpressure.

[z284pwr]

I see 14.0 - 14.3 PSI constantly at WOT on a T-25 with about 170,000 miles on it.

 

Are you running an aftermarket boost controller or the stock WasteGate Actuator circuit?

 

If stock WGA are you running a stock chip? Stock chip = 7 - 8psi

 

If you are aftermarket boost controller or raised boost chip and you do not see more than 7 - 8psi then most likely the wastegate diaphram spring is week and allowing the wastegate to open due to backpressure.

 

Stock boost controller, new wastegate diaphgram, aftermarket chip.

[Nick1234]

i cant get more than 8. I will have to look into the wastegate diaphram. I think skalor programmed the chip to run at 11.

[Guest TurboSedan]

about 12-13psi, that is using a grainger valve MBC. that was with the junk Autometer mechanical boost gauge though. key on/engine off it read 2psi so i don't know if that was actually 10-11psi or what.

 

http://www.turbosedan.com/lebaron/DSC01553.JPG

[Nick1234]

mine reads like 1 on the vaccuum side.

[futuretgper]

whats was the temp like when you were looking?? is it possible that the t25 might not make full boost when its hot out?

[mfewtrail]

I briefly installed a VDO boost gauge in my TGP a while back, it was reading right at 10-11psi max. This was in 70* temps for what it's worth. I'm using the stock boost controller & a Topgun 160 chip.

[z284pwr]

It wasn't very hot at all, the car was barely running at 160, it was at 3 in the morning so it was in the 70s I'm sure.

 

I may have to break out a wire tie or actually wire or something and tie the wastegate closed to verify this, as I'm at 4400+ feet this is okay...

 

Could a built engine really have that much to do with it too?

[intern8tion9l]

12psi. nordskog boost gauge, joe p boost controller, aftermarket chip

[z284pwr]

I used wire and closed the wastegate completely and it still is less than 7....

 

Does anyone have a datamaster datalog and can look up the HG reading of full boost from it, so I can verify this gauge isn't out to lunch.

 

[mfewtrail]

I used wire and closed the wastegate completely and it still is less than 7....

 

Does anyone have a datamaster datalog and can look up the HG reading of full boost from it, so I can verify this gauge isn't out to lunch.

 

 

Brian, I copied this list from another site(MAP voltage & corresponding kpa & psi reading). For what it's worth, the numbers are rounded up.

 

Map V kPa

 

0.0 v 8.8

0.25 v 18

0.50 v 28

0.75 v 38

1.00 v 48

1.25 v 58

1.50 v 68

1.75 v 78

2.00 v 88

2.25 v 98

2.50 v 108 (0.96 Psi)

2.75 v 118 (2.41 Psi)

3.00 v 128 (3.86 Psi)

3.25 v 138 (5.32 Psi)

3.50 v 148 (6.77 Psi)

3.75 v 158 (8.22 Psi)

4.00 v 168 (9.67 Psi)

4.25 v 178 (11.12 Psi)

4.50 v 188 (12.57 Psi)

4.75 v 198 (14.01 Psi)

5.00 v 208 (15.47 Psi)

[z284pwr]

I used wire and closed the wastegate completely and it still is less than 7....

 

Does anyone have a datamaster datalog and can look up the HG reading of full boost from it, so I can verify this gauge isn't out to lunch.

 

 

Brian, I copied this list from another site(MAP voltage & corresponding kpa & psi reading). For what it's worth, the numbers are rounded up.

 

Map V kPa

 

0.0 v 8.8

0.25 v 18

0.50 v 28

0.75 v 38

1.00 v 48

1.25 v 58

1.50 v 68

1.75 v 78

2.00 v 88

2.25 v 98

2.50 v 108 (0.96 Psi)

2.75 v 118 (2.41 Psi)

3.00 v 128 (3.86 Psi)

3.25 v 138 (5.32 Psi)

3.50 v 148 (6.77 Psi)

3.75 v 158 (8.22 Psi)

4.00 v 168 (9.67 Psi)

4.25 v 178 (11.12 Psi)

4.50 v 188 (12.57 Psi)

4.75 v 198 (14.01 Psi)

5.00 v 208 (15.47 Psi)

 

Thanks Matt

 

From what I'm going off now, either the gauge is out to lunch or the engine just pulls in/puts out enough air that the turbo can't keep up. I know on top end thats definitely how it is. If its not and it is actually only getting 7.5 psi something is wrong, because the COLDER is gets, the LESS boost it makes, that and the fact that if its only putting out 7.5 PSI I don't want to know what 12-14 is like, this little shit head of a car is fast. With the new stall it smokes the tires instally, hooks and hits 60 in no time, I also PEGGED the EGT gauge tonight, which is a 1600*+ EGT by 70 MPH when I let off :eek:

 

I have the wastegate wired closed, with no vacuum line on it and the gauge only showed like 6 PSI at the time, no datalog to verify though

[Nick1234]

i think i have the same problem as you.

[Jeff M]

Now, just let me get after you guys a little and don't freak or take it personal, just something as with everything I post, its also for all people to read since its a public forum and a lot of people read here/duh and may find themselves with the same problem later and when doing a "Search" !

 

When the car is not running right, DO NOT keep beating on it If you know something is wrong well then.....something is wrong!!!! Anyone can and will do way more damage than the "something wrong" if you pushing it hard over and over.

 

Ok, enough trying to save ass If not a blown off or leaking intake/boost hose/coupling, then a good chance a plugged cat, and with those EGT readings, sounds real likely! So, get this checked and no more wanging on that poor turbo/engine till you find a problem and need to test if the condition is gone !

 

Best of luck!!!

 

ps, for those that try chip tuning, the kPa scale on your tuning tables might not fully agree with the chart on your scanner, it can be off more so on one end and closer on the other, need to consider that when tuning or looking at the scanner to compare boost levels.

 

Jeff M

[Nick1234]

i don't have a cat. And i have double checked all of the couplings to make sure they are tight. i have not been driving the car either.

 

Current problems:

 

Loss of braking power

needs new starter

will not idle. always dies. chugs while idles if it does stay running. checking the crossover shortly

possible alternator

 

 

[z284pwr]

Now, just let me get after you guys a little and don't freak or take it personal, just something as with everything I post, its also for all people to read since its a public forum and a lot of people read here/duh and may find themselves with the same problem later and when doing a "Search" !

 

When the car is not running right, DO NOT keep beating on it If you know something is wrong well then.....something is wrong!!!! Anyone can and will do way more damage than the "something wrong" if you pushing it hard over and over.

 

Ok, enough trying to save ass If not a blown off or leaking intake/boost hose/coupling, then a good chance a plugged cat, and with those EGT readings, sounds real likely! So, get this checked and no more wanging on that poor turbo/engine till you find a problem and need to test if the condition is gone !

 

Best of luck!!!

 

ps, for those that try chip tuning, the kPa scale on your tuning tables might not fully agree with the chart on your scanner, it can be off more so on one end and closer on the other, need to consider that when tuning or looking at the scanner to compare boost levels.

 

Jeff M

 

Lets see here...

 

Brand new exhaust...

Plus a cam that has little overlap and has ALWAYS had high EGT readings, even cruising

 

If this thing isn't running right, I don't want to know what "right" is...

 

I don't think anything is wrong at all with the way the car runs. It runs pretty damn good for being at 4500 ft. elevation.

 

Oh and I don't see what using a search is going to do with questioning guys what they have as a boost gauge reading.

The gauge is probably just screwed up as it used to always get close to 12psi according to datalogs.

 

 

[Jeff M]

This posted edited for excess content

 

Jeff M

[Jeff M]

After digesting that long ass post from Jeff M and thinking more about the parts you said during this topic, trying to narrow this down:

 

You had datalogged 12 psi with your aftermarket chip?

Stuck on a boost gauge and only read 7psi?

Wondered if the datalogger was wrong or the boost gauge?

Wired wastegate shut (bit of a no-no) and boost gauge still showed 7psi and datalogger said?_________?

 

Do I have that right?

 

Jeff M

[z284pwr]

Thanks for editing your long post with all the info I was going to reply to Jeff......not

 

Anyways,

 

Here is what I have just discovered...

 

You had datalogged 12 psi with your aftermarket chip?

Stuck on a boost gauge and only read 7psi?

Wondered if the datalogger was wrong or the boost gauge?

Wired wastegate shut (bit of a no-no) and boost gauge still showed 7psi and datalogger said?_________?

 

I have only ever datalogged ONE time it actually running at 12 PSI, with 3 different chips I have....

Boost gauge and datalog are pretty much the same after the datalog I just ran

Wastegate wired closed, still only 7.5 PSI

 

I went back and look at every datalog I have ever taken, and even one of the ones with the TopGun160 chip the highest MAP reading I had was 165.

 

Maybe that is why I doesn't feel like it has ever slowed down, because its always had that same MAP reading with all the chips, hell, even the STOCK chip, WITH the wastegate hooked up was 160 KPA.

 

Oh yeah, there was no spark retard being showed either.

 

All of the datalogs except for the one that did actually have ~12PSI all have similar style of Wastegate readings, its the only one that has a different style of reading....Plus its about the only time the Duty Cycle has pasted 80%

 

So, wiring the wastegate closed hasn't changed anything and over the winter I have managed to misplace the TopGun chip so I have to search around for it....

 

[Jeff M]

Yea after that last long post I was a man and admitted it was overboard, so on to the details now that it at least set some concepts and actions into the right direction.

 

So it sounds as though one time you got 12 psi, but something changed and now no matter what chip or efforts to the wastegate you only get 160-165 kPa or about 7.5 to 8.5 psi.

 

First is the wastegate duty cycle should show as much value as it takes to achieve the chip’s boost setpoint so if the chip says 10-12 psi then the wastegate duty cycle should be maxing out up near if not at 100% or until the setpoints of 10-12 psi are achieved where it will back down to around 80% or so. Not absolutely sure you are getting a wastegate DC showing this? Please confirm before I get into that.

 

Aside from that, do you remember back when the boost was no longer 12 psi and was a slow ass running 7.5 psi car!!!, like you had just done some work such as removed the intercooler to clean out the oil or the intake pipe to clean out the throttle body or something like that, where you might be lucky and just have an intake hose leaking off all your boost, meaning the turbo is spooling insane speeds ( ouch) but not getting that boost into the engine because of a loose intake hose somewhere. The most common is the one at the throttle body, underneath where you cannot see and it’s hard to get fitted properly! Check there first as well as a rip in the hose/common after all these years and people working in those areas, then onto the rest looking for loose or ripped intake hose couplers. Will this find your problem?, maybe not but a systematic approach of one thing at a time has to be done, worse to just jump all over the place, must first nail down the easy and most likely candidates.

 

Another chance is a bad coil pack or ignition module or plug/wire, heard of this a number of times when someone complaining about a hard starting and/or engine miss resulting in one of these ignition parts being bad and once replaced, owner then found all this new power that was not there before.

 

Your air filter is large engine, clean and fitted to the turbo or has some hoses running elsewhere?

 

Those are the most common suggestions, if you have done all this then don’t freak me asking, just need to make sure before going on to other suggestions .

 

Jeff M

[z284pwr]

Hey no big deal, some of us are okay with overboard and won't freak out.

 

The engine was recently just put back into the car with a new trans and what not but it still didn't change the boost before then.

The wastegate now usually starts out at 0 and slowly throught the RPMs steps up and by ~4900 RPM its at 100% which is what all the datalogs show with how its currently running as where the 12psi one it climbed FAST up to ~55% and actually DROPPED from there.

 

And honestly I really never noticed when it stopped boosting as much? With as much as we have modified I just drove the thing and never really worried about it or noticed.

 

I have a boost leak checker that we made and it doesn't show any boost leaks at all, just the air escaping through the open exhaust valves is all, no other leaks other than that.

 

All 3 coil packs are new so I dunno about that one. It starts just fine and doesn't miss. The air filter isn't dirty and was recently oiled as well. Its directly on the turbo.

 

Oh driving home just down the freeway a few times after I had driven the car, the SES light came on with a Code 43 error. Which I would have no ideas on what this would be. It doesn't affect how the car is running or anything and it never did it before the engine was out. I doubled checked the wires on the ignition module to ensure they were on.

 

I haven't had time to check further on that one....joy for issues

[Jeff M]

Owww, I had a reply but board went down for some work. So here it was.

 

Ahh, we cool on talking thats good

 

Umm, I don't typically do this but I am going to jump right off and say your knock sensor wire is unplugged :exclaim:

 

A SES Code 43 is in regards to the knock sensor, if it is not working like the wire off then the timing will be retarded, though my scan tool will show the standard 7 degree of knock retard with a Code 43, not sure if your will but since we DO GOT something like this to go on, I am hoping its an easy fix

 

Other than that, thanks for the reply to all my questions and all the details , they will come in handy if the knock sensor/wire is not the problem .

 

Till then.

 

Jeff M

 

[z284pwr]

Owww, I had a reply but board went down for some work. So here it was.

 

Ahh, we cool on talking thats good

 

Umm, I don't typically do this but I am going to jump right off and say your knock sensor wire is unplugged :exclaim:

 

A SES Code 43 is in regards to the knock sensor, if it is not working like the wire off then the timing will be retarded, though my scan tool will show the standard 7 degree of knock retard with a Code 43, not sure if your will but since we DO GOT something like this to go on, I am hoping its an easy fix

 

Other than that, thanks for the reply to all my questions and all the details , they will come in handy if the knock sensor/wire is not the problem .

 

Till then.

 

Jeff M

 

 

No luck on easy fix, I jacked the car up and pushed on the wire connector and it was definitely plugged in

 

However, it definitely pulling out 7 degrees of advance when I got the SES light to show when I was datalogging.

[Jeff M]

No luck on easy fix, I jacked the car up and pushed on the wire connector and it was definitely plugged in

 

However, it definitely pulling out 7 degrees of advance when I got the SES light to show when I was datalogging.

 

Welllll, you are not going to stop now . That's still not right so fix it Something in that area is whack so, need to address it till its right! Is your boost lame when the SES/Code 43 happens? Even if not lets get that issue resolved. I have a local TGP owner who had this problem and it was the worst I had every dealt with, after checking the connections at the knock sensor (this is a list yet for you to do ) and ECM and no problem there (on his), then replaced the knock sensor and after all that, still had the problem decided to trace the knock wire, it ran through a lot of areas so yours could be chafed somewhere, but his wire was fine and did not run near anything that would cause interference either, but not wanting to assume too much, and not wanting to give up on it I found some wire I had that was a shielded type to see if that made things happy. With the new wire I made new connections at both ends; knock sensor/ECM, then on only one ( ) end I grounded the braided shielding to a good ground and damn, got that stupid thing fixed It ran with no more problems now for 5 years

 

So since I remember how poor his gas mileage and performance was with 7 less degrees of timing all the time lets get that issue gone then see how the boost is not saying for sure this will fix the boost, just better to start with everything else right first!

 

Jeff M