Trying to dial in my 99 twin turbo-questions?

[paulb]

Your ECT problem is most likely because the rad is caked with oil and dirt. The VP44 trucks will draw the oil vapors from the crankcase vent, and plug up the rad. To clarify, it the outside of the rad that gets dirty, not the inside. Some people have luck with using a car wash from the fan side of the rad and cleaning it. I prefer to just remove the rad and carefully use a pressure washer to throughly clean it. If it is good and clean you should not have an overheating problem.

Paul

 

[skav]

I just talked to II and got some info on the turbos.

S300: 62/65/.14 T3 said to set the WG at 20psi
K31: 71/84/.16 said to keep the WG as tight as I could.

Do these numbers help?


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[skav]

Your ECT problem is most likely because the rad is caked with oil and dirt. The VP44 trucks will draw the oil vapors from the crankcase vent, and plug up the rad. To clarify, it the outside of the rad that gets dirty, not the inside. Some people have luck with using a car wash from the fan side of the rad and cleaning it. I prefer to just remove the rad and carefully use a pressure washer to throughly clean it. If it is good and clean you should not have an overheating problem.

Paul

Thanks for the info Paul. I'll try that today. I've thought about rerouting the vent to the back of the cab


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[skav]

I ran an S300/K31 set up for several years. Going small on the secondary(s300) was a headache with mine. Bumping up to a 62/71/.8 really helped when i was at the 500 hp level. It spooled slightly slower, but ran cooler and made good power with less boost. A set of Mach 4's might be a better match for the power level you are looking for. 6 x .024's are just plain silly. Contact Smokem or SDX on this site and see about a better set of injectors.

What size was your S300 before you went to the 62/71/.8? That seems like a super tight exhaust housing. How does that compare to the 62/65/.16 that I have? My ex wheel is smaller, but the ex housing is bigger.


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[RonA]

What size was your S300 before you went to the 62/71/.8? That seems like a super tight exhaust housing. How does that compare to the 62/65/.16 that I have? My ex wheel is smaller, but the ex housing is bigger.


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I tried a 57/65/.7, and 62/65/.8 before going to the 62/71/.8.

.7 a.r. = 12 cm.
.8 a.r. = 14 cm.
If you have a k31 for the Detroit 60 series application as a primary charger it will have a T6 wastegated exhaust housing that's around 1.24ar or 1.28ar or so.

 

[skav]

I tried to check the secondary WG today, but my regulator wouldn't go low enough, so I ordered one that will.

I did get a boost gauge on the primary turbo, and took notes of primary and secondary pressures. Also, while I was installing the primary boost gauge, I had to remove the compressor discharge pipe from the primary to the secondary. There was no o-ring, so I found a 3 1/4" o-ring to seal the discharge. That must have helped, just not sure how much yet. I will say that cruising at 10psi is right at 700* and 20psi is 900*.

Here are my quick observations. I'm going to install a drive pressure gauge, so I'll get more info on that later.

Primary Secondary
1-2psi 10psi
5psi 15psi
10psi 25psi
20psi 40psi (I didn't have much time to run it at 40psi, but I had the pedal buried w zero smoke. I feel like I could definitely use bigger sticks.)

How do these numbers look? I'm still on level 2 in the Smarty. I'll start testing different levels tomorrow. What else should I be looking at?

 

[inline6power]

I tried to check the secondary WG today, but my regulator wouldn't go low enough, so I ordered one that will.

I did get a boost gauge on the primary turbo, and took notes of primary and secondary pressures. Also, while I was installing the primary boost gauge, I had to remove the compressor discharge pipe from the primary to the secondary. There was no o-ring, so I found a 3 1/4" o-ring to seal the discharge. That must have helped, just not sure how much yet. I will say that cruising at 10psi is right at 700* and 20psi is 900*.

Here are my quick observations. I'm going to install a drive pressure gauge, so I'll get more info on that later.

Primary Secondary
1-2psi 10psi
5psi 15psi
10psi 25psi
20psi 40psi (I didn't have much time to run it at 40psi, but I had the pedal buried w zero smoke. I feel like I could definitely use bigger sticks.)

How do these numbers look? I'm still on level 2 in the Smarty. I'll start testing different levels tomorrow. What else should I be looking at?

please read the tuning twins thread. Tuning Twins - Competition Diesel.Com - Bringing The BEST Together
your secondary is not making 10psi, 15psi, 25psi, 40psi, that is your overall manifold boost if your taking that boost reading after your secondary piping.

 

[skav]

please read the tuning twins thread. Tuning Twins - Competition Diesel.Com - Bringing The BEST Together
your secondary is not making 10psi, 15psi, 25psi, 40psi, that is your overall manifold boost if your taking that boost reading after your secondary piping.

I meant to make a manifold boost column, but got side tracked while posting. I know that you subtract the primary from the manifold to get the secondary pressure. I'll correct it when I get back to my computer.

What do you think about the numbers?


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[skav]

Here are the correct primary, secondary and manifold pressures.

Primary Secondary Manifold
2-2.5psi 7.5-8psi 10psi
5psi 10psi 15psi
10psi 15psi 25psi
20psi 20psi 40psi

How do these ratios look? Again, there was zero smoke.

 

[inline6power]

I meant to make a manifold boost column, but got side tracked while posting. I know that you subtract the primary from the manifold to get the secondary pressure. I'll correct it when I get back to my computer.

What do you think about the numbers?


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Here are the correct primary, secondary and manifold pressures.

Primary Secondary Manifold
2-2.5psi 7.5-8psi 10psi
5psi 10psi 15psi
10psi 15psi 25psi
20psi 20psi 40psi

How do these ratios look? Again, there was zero smoke.

again please read that thread i linked you. you have it all wrong. if your making 40psi overall at the manifold and your primary is making 20psi, your secondary is only making 8.3 psi of boost.

40psi gauge overall boost is = (14.7+40psi)/14.7 = ~3.72
20psi gauge primary boost is = (14.7+20psi)/14.7 = ~2.36

so then you divide your overall pr by your primary pr to get your secondary pr
so 3.72 divided by 2.36 equals 1.57 pressure ratio for your secondary turbo.
now reverse formula to get secondary boost. 1.57*14.7-14.7= 8.37 psi of boost. so this means your small turbo is only making 8 psi of boost on top of compounding the larger turbo. again please re read the thread i linked and you will start to understand the logic of compounds.

 

[skav]

again please read that thread i linked you. you have it all wrong. if your making 40psi overall at the manifold and your primary is making 20psi, your secondary is only making 8.3 psi of boost.

40psi gauge overall boost is = (14.7+40psi)/14.7 = ~3.72
20psi gauge primary boost is = (14.7+20psi)/14.7 = ~2.36

so then you divide your overall pr by your primary pr to get your secondary pr
so 3.72 divided by 2.36 equals 1.57 pressure ratio for your secondary turbo.
now reverse formula to get secondary boost. 1.57*14.7-14.7= 8.37 psi of boost. again please re read the thread i linked and you will start to understand the logic of compounds.

Thanks.... but subtraction is easier than the other stuff you did.







Thanks again. Those numbers seem pretty low to me. Worse now that you actually did the correct math!

 

[RonA]

Here are the correct primary, secondary and manifold pressures.

Primary Secondary Manifold
2-2.5psi 7.5-8psi 10psi
5psi 10psi 15psi
10psi 15psi 25psi
20psi 20psi 40psi

How do these ratios look? Again, there was zero smoke.

That looks good. 550-600 degs at 60 mph on level ground with 3.55's and 31" tires is what i would expect with twins like that.

 

[inline6power]

Thanks.... but subtraction is easier than the other stuff you did.







Thanks again. Those numbers seem pretty low to me. Worse now that you actually did the correct math!

you need to work your primary a tad bit harder. if your K31 is wastegated, just for chits and giggles, take a pair of vise grips and pinch shut the wastegate hose to the K31 and make a pass, bet you make a ton more boost and egts will be alot lower.

 

[inline6power]

That looks good. 550-600 degs at 60 mph on level ground with 3.55's and 31" tires is what i would expect with twins like that.

i wish lol. my little 57 over 475 only drives at 650 at 60mph and i am right at 790-800 at 70mph. sure wish i knew how people were getting such cool egts while just crusing. although i cant get mine over 1100 even if i tried lol but still.

 

[skav]

That looks good. 550-600 degs at 60 mph on level ground with 3.55's and 31" tires is what i would expect with twins like that.

Your super close. Right at 700*-35s and I think 3.55s but I can't remember.

 

[skav]

you need to work your primary a tad bit harder. if your K31 is wastegated, just for chits and giggles, take a pair of vise grips and pinch shut the wastegate hose to the K31 and make a pass, bet you make a ton more boost and egts will be alot lower.

I don't even have the hose on the primary WG now. Trying to figure out what else to check.

How much will the smarty change things if I go past level 2?

 

[inline6power]

I don't even have the hose on the primary WG now. Trying to figure out what else to check.

How much will the smarty change things if I go past level 2?

so wait let me get this straight, you had the hose on but you took it off? how are you controlling the boost leak from the hose and how are you actually controlling your wastegate now? just because you took the line off dont mean you disabled your wastegate.

 

[RonA]

35's will screw up the temps a bit. Like was said, you can probably loosen up your wastegate on the seconday, but wait till you can see where it is with a gauge. Check where your k31's gate is opening too. If it's set too light it can open with drive pressure even though the hose is off. How much boost are you seeing to the manifold at 60-65 mph?

 

[skav]

so wait let me get this straight, you had the hose on but you took it off? how are you controlling the boost leak from the hose and how are you actually controlling your wastegate now? just because you took the line off dont mean you disabled your wastegate.

The line was cut and the turbo side was plugged when I ended up w it. I pulled the plug and am using that line to read boost on the primary right now.

What would open the gate assuming that the spring is strong enough to hold it closed?

 

[skav]

35's will screw up the temps a bit. Like was said, you can probably loosen up your wastegate on the seconday, but wait till you can see where it is with a gauge. Check where your k31's gate is opening too. If it's set too light it can open with drive pressure even though the hose is off. How much boost are you seeing to the manifold at 60-65 mph?

I'll test it when I get the other regulator in. How can I hold it closed longer other than changing the spring or wiring it shut?