HELP, tuning my turbo setup

[97m34]

OK guys here it is. The last couple of weeks or so my buddy and I have been trying to tune up the 1995 M3 custom turbo I bought to replace my 1997 M3/4. I got the car from my father, felt bad about my M and really doesn't drive it. He bought it a few years ago due to his '85 euro M6 turbo kept blowing HG's but has fixed that problem. Then he blow the HG in the '95 due to over boosting. So that's how I acquired this 1995 M. Over the winter the HG was replace and a Dr. Vanos was also installed, ARP 2000 HS.

Here is the specs.

custom turbo header
T67 Precision with .81 exhaust hsing
spearco 5' core front mount
83lb injetors
twin in tank holley
custo grind webb cams
DTA stand alone pro 8 comp.
tial blowoff/ tial F40 wastegate
weisco pistons
pauter connecting rods
custom front mount oil cooler
ZF sachs racing twin disc clutch
3.5" custom exhaust w/racing dynamics muff

Ok, supposedly this car was tuned for 16psi also had 16lb WG spring. Last year my father and took it out for a rip and saw 27psi!!! BOOM. Now this year I tryed to knock down the boost (for tuning) by useing an 8lb spring in the wastegate, also the tial(40) wastegate has been put into the snail of the turbo. Also the DTA has a electric boost presure switch(E-boost)

So we after getting my old ass IBM think pad to open the DTA zip file we started tuning friday. The AFRs were way off!!! I think the PO ran some kind off RACE fuel in it since he owned a offshore boat racing motor shop but just speculation. We dialed the afr in 5 psi at a time, is was going GREAT!!! Now gave it a good 4th gear rip and couldn't take to7k because I was getting so serious Boost creep. I saw 19-20psi at 5800-6000 on this 8lb WG spring. After 3hours of tuning we stop due to this issue..... I was thinking of putting the 16lb WG spring back in and starting over, but would I get even more boost creep is the question?????? Also I disconected the smart valve and went from the compresser to the WG just to see it the WG is working and it is, bleeding off at 8psi and still I see 19-20psi around 6k....

So is this turbo too BIG!!!! or do I need a bigger WG or maybe two???? Also after looing into the PO files it look the they just got it to run........

Please help me out I know there are alot of SMART people here, not a squid here.... I have been building my cars since 16yrs old, just this is the biggest HP motor I have delt with and my first time with the DTA..... My buddy has built alot of MS setups and my father run the TEC R on his M6. So we do know are way around the stand alones. Just don't want to blow it up again......

Thanks guys
Wesley

[black bnr32]

Tell us more about your exhaust manifold and your wastegate plumbing. Pics help too.

[97m34]

Tell us more about your exhaust manifold and your wastegate plumbing. Pics help too.

I wish I took pics when is was out but I didn't...... Anyhow it's is a custom tubular mani. with the turbo down low. it has a scavenger pump on it and the WG is right on the exhaust housing, pipe comes off the exhaust housing about 3" to the WG and WG dumps to atmosphere from a pipe about 4" with a 90 pointing to the ground.........

This turbo pulls like a freight train...... doesn't stop boosting.......

[black bnr32]

Oh well.

Its very possible the design of the exaust manifold is contributing some creep, along with a large turbo.

How are the lines plumbed for the wastegate and BOV?

The size of your wastegate & turbo should be fine and putting in the 16lb spring will make creep better (I think).

You can check 5mall5nail5's build thread for recent boost creep discussions.

I'm certainly no expert BTW!

[97m34]

Oh well.

Its very possible the design of the exaust manifold is contributing some creep, along with a large turbo.

How are the lines plumbed for the wastegate and BOV?

The size of your wastegate & turbo should be fine and putting in the 16lb spring will make creep better (I think).



I'm certainly no expert BTW!

Thanks

BOV is right on the charge tube about 4-5" away from the TB. The WG has a total of 7-8" of pipe 3" off the turbo and 5" off the WG which dump the atmosphere.......





"You can check 5mall5nail5's build thread for recent boost creep discussions."

Honestly I don't even no where to start in that tread, I tried looking for some of his DTA info.............

[Ted B]

tial(40) wastegate has been put into the snail of the turbo.
...
So is this turbo too BIG!!!! or do I need a bigger WG or maybe two????

It isn't clear to me specifically which wastegate you have. It would be a good idea to correctly identify it.

Maintaining a paltry 8psi indicated boost with an engine of that displacement and a 750+hp turbo requires a substantial amount of exhaust gas to be bypassed through the WG. If the WG valve is too small, creep will be unavoidable.

I haven't seen your WG arrangement, but it sounds to me like your WG may be too small and your turbo too large for what you want.

[97m34]

It isn't clear to me specifically which wastegate you have. It would be a good idea to correctly identify it.

Maintaining a paltry 8psi indicated boost with an engine of that displacement and a 750+hp turbo requires a substantial amount of exhaust gas to be bypassed through the WG. If the WG valve is too small, creep will be unavoidable.

I haven't seen your WG arrangement, but it sounds to me like your WG may be too small and your turbo too large for what you want.

Ted

(edit)Sorry the WG is a Tial F 40 which they no longer have. So would you say I put the 16lb spring back in a start over with my tuning? This is also not my build, just trying to get it to run right or as best i can with what I have.......

Thanks
Wesley

[Ted B]

I remember the F40 with it's finned housing.

The fact that plumbing the WG signal directly to the compressor results in tremendous boost creep implies either the WG is too small, and/or its mounting location is such that the WG isn't very effective.

In this case, I suspect mostly the former. IF this proves to be the case, it would seem to leave you with two logical choices:

(1) Go to a larger WG (e.g. Tial V60).

(2) If you have confidence in the build quality of the shortblock and the sealing point between head and block, leave all as-is, and make full use of that large turbo and IC by accepting what it gives at 19-20psi boost.

If it were me, I would be tempted to go with the latter option. IMO, asking small power from a large turbo doesn't really justify the slower spool characteristics and transient response .

I would be tempted to (carefully) tune my way to accepting a full 20 psi from that turbo. I don't know what you are using specifically for boost control, but I would use it to begin tuning in the lower rpm ranges, and get my indicated AFR to ~11.5:1 from the point the turbo starts spooling, and use conservative ignition values (e.g. <10 deg), while gradually tweaking the ignition map to find the threshold of detonation.

And where the detonation threshold is concerned, I hope that standalone ECU has effective knock control capability, or things will become trickier...

[black bnr32]

Tell us about the lines controlling your gate and BOV.

[97m34]

I remember the F40 with it's finned housing.

The fact that plumbing the WG signal directly to the compressor results in tremendous boost creep implies either the WG is too small, and/or its mounting location is such that the WG isn't very effective.

In this case, I suspect mostly the former. IF this proves to be the case, it would seem to leave you with two logical choices:

(1) Go to a larger WG (e.g. Tial V60).

(2) If you have confidence in the build quality of the shortblock and the sealing point between head and block, leave all as-is, and make full use of that large turbo and IC by accepting what it gives at 19-20psi boost.

If it were me, I would be tempted to go with the latter option. IMO, asking small power from a large turbo doesn't really justify the slower spool characteristics and transient response .

I would be tempted to (carefully) tune my way to accepting a full 20 psi from that turbo. I don't know what you are using specifically for boost control, but I would use it to begin tuning in the lower rpm ranges, and get my indicated AFR to ~11.5:1 from the point the turbo starts spooling, and use conservative ignition values (e.g. <10 deg), while gradually tweaking the ignition map to find the threshold of detonation.

And where the detonation threshold is concerned, I hope that standalone ECU has effective knock control capability, or things will become trickier...

Ted

I guess I will put the 16lb spring back in, and tune AFR's to 20psi or so. I also have installed meth, had it from my SC'er might as well use it. The DTA has a smart boost control which was not setup at all with the PO. He had it set at 280kpa. So I guess I'll start 100-120kpa value or so, set the boost control at 16psi or lower psi or high psi to start????


thanks

Tell us about the lines controlling your gate and BOV.

Control of the BOV is coming from the intake directly. The WG is plumb like this, off the compressor with T to side port of the WG and up the the electric Pressure switch then out of the PS to the top port of the WG.

Make sence, wish i could draw it for you.

[Ted B]

Your description of WG signal routing appears to be correct.

I would create my base tune without methanol injection. Once you have that worked out, then you can tinker with that.

Tuning with the 16psi spring shouldn't be a problem - assuming you are skilled at tuning and the ECU has effective knock control. If not, that will spawn a different topic of discussion: Tuning without the Benefit of Knock Control.

[97m34]

Your description of WG signal routing appears to be correct.

I would create my base tune without methanol injection. Once you have that worked out, then you can tinker with that.

Tuning with the 16psi spring shouldn't be a problem - assuming you are skilled at tuning and the ECU has effective knock control. If not, that will spawn a different topic of discussion: Tuning without the Benefit of Knock Control.

Ted

Just went through the 36pg manual and didn't see any thing about a knock sensor......... also I have heard that DTA doesn't use one, I'll try to get a hold my buddy who's assisting with the tuning he does know a whole lot more than me when it comes to stand alone systems. I'll ask him, and yes he is very skilled with these systems. So now what kind of animal I'm I dealing with????

Thanks

[Ted B]

Not having knock control for any street driven engine is disadvantageous. Why? Because the only means of getting the most out of tuning is finding the detonation threshold. The problem with a turbo engine is that given the high torque output, if you actually hear the engine start knocking with your naked ears, it may already be too late.

I would recommend one of three options:

(1) Replace the standalone with something more capable.

(2) Construct a set of inexpensive 'det cans' and learn how to use them:
http://turbod16.com/viewtopic.php?f=...&hilit=det+can

(3) Buy a standalone knock control setup, such as the proven J&S units:
http://www.jandssafeguard.com/


Either of these is much cheaper than addressing a blown engine.

[97m34]

Not having knock control for any street driven engine is disadvantageous. Why? Because the only means of getting the most out of tuning is finding the detonation threshold. The problem with a turbo engine is that given the high torque output, if you actually hear the engine start knocking with your naked ears, it may already be too late.

I would recommend one of three options:

(1) Replace the standalone with something more capable.

(2) Construct a set of inexpensive 'det cans' and learn how to use them:
http://turbod16.com/viewtopic.php?f=...&hilit=det+can

(3) Buy a standalone knock control setup, such as the proven J&S units:
http://www.jandssafeguard.com/


Either of these is much cheaper than addressing a blown engine.

Thanks Ted

for now I'm going to have to go with the option (2) for now. I just can't go for another S.A. right now.... Just looking to get this M running good, had a good amount of $$$ into my sedan before it got wrecked and barely going to get out of what I had in.

So some time this week will do another tune up with the 16lb WG spring and setup the correct kpa for the smart gate, and go from there. So with the 16lb WG will I get even more boost creep? will it go say 30psi????

Thanks
Wesely

[Ted B]

So with the 16lb WG will I get even more boost creep? will it go say 30psi????

I wouldn't expect that to happen. Although, I'm not sure you should deal with anything other than the 8lb spring at the present.

[97m34]

I wouldn't expect that to happen. Although, I'm not sure you should deal with anything other than the 8lb spring at the present.

Ok, so leave the 8lb in for now?????

[Colby Colbs]

take pics bro

[SiGmA]

Post some pictures. I'm still confused as to where the wg is tied in period.

Also, you might consider running it with out a Wastegate period and seeing what it makes.

[///36M]

Wes I didn't know you wrecked your sedan, that sucks.

Do you have a 413 or 503 DME laying around?

Did you figure out how to watch knock on the Tec3? Did you try contacting Vick Sias?

You have a pretty stout build there. I wouldn't be too worried about blowing a rod through the block. Did you try the 16psi spring?

[97m34]

Post some pictures. I'm still confused as to where the wg is tied in period.

Wes I didn't know you wrecked your sedan, that sucks.

Do you have a 413 or 503 DME laying around?

Did you figure out how to watch knock on the Tec3? Did you try contacting Vick Sias?

You have a pretty stout build there. I wouldn't be too worried about blowing a rod through the block. Did you try the 16psi spring?

Thanks, I didn't wreck the sedan some woman ran a red light!!!! No i don't have any 413 or 503 here.......... How you been????



.

Here's some better pics of the WG placement, what do you guys think????..... Anyhow I'm going to put the 16lb spring back in and go test the water and tune.......

[cameltow]

Well look at that....... wish I could help. hmmmm

[zak]

Uhhhh....most people who tap the exhaust manifold for the wastegate do it at the inlet, not on the other side of the turbo. A lot of the air has already traveled around the turbine at that point. I would suggest you either tap a pipe into the manifold and run the wastegate there or do it at the inlet of the turbo. The first suggestion would by far be the best.

[calvino]

Agreed, your problem is that with your wastegate placed AFTER the exhaust gases have ENTERED the turbo, its too late for the wastegate to funtionally bypass any gases. The wastegate MUST be relocated before the turbine housing. I get the feeling that someone got internal and external wastegate operations confused...

Uhhhh....most people who tap the exhaust manifold for the wastegate do it at the inlet, not on the other side of the turbo. A lot of the air has already traveled around the turbine at that point. I would suggest you either tap a pipe into the manifold and run the wastegate there or do it at the inlet of the turbo. The first suggestion would by far be the best.

[bluejeansonfire]

if you plan to keep this setup, i recommend using a popoff valve to limit boost

if you want to do it right, read the previous posts

I wouldn't put a 16lb spring in there and try anything... not without a popoff valve

[Perfection Auto]

The wastegate is mounted wrong i wouldnt run a waste gate so close into the turbine housing as it would not vent the gases for such low boost an application like that is more for hi boost as the flow of gases rely on such hi boost to go out that path of the waste gate were as low boost would not work well big turbo small gate bad mounting hmm just a theory.

im all with you on that!!

Agreed, your problem is that with your wastegate placed AFTER the exhaust gases have ENTERED the turbo, its too late for the wastegate to funtionally bypass any gases. The wastegate MUST be relocated before the turbine housing. I get the feeling that someone got internal and external wastegate operations confused...