7845

iTrader: (1)

I have a 60mm tial gate. currenty its dumped to atmosphere. i removed the 5psi spring so i only have the 10psi spring in there. the wastegate is in the crossover pipe. this is same setup as other truck turbo kits from Trick or Kbracing. i have the top of gate with a hose on it vented to atmosphere. i have side port referenced off turbo.. i was using a Greddy profec S EBC but i bypassed it for now.

the problem is my setup is seeing more boost then 10psi. and im not sure the gate is opening. i checked my vaccum line with my air compressor and no leaks or clogs. i also applied air to the gate to see if valve opens and it does. now is there a reason why im seeing more boost then what the gate is set for? should i reference the gate from the intake instead of the snail?

NLR

poor location of the wastegate. The exhaust takes the path of least resistance and it seems to be towards the turbo. Take the wastegate completely off and I bet it makes the same. The fix is to mount the wastegate in a priority location- so the valve of the wastegate face oncoming exhaust flow.

kbracing96

iTrader: (25)

A turbo runs on pressure, to maintain a boost level, you maintain a drive pressure. A WG regulates this pressure and shouldn't make any real difference where it is mounted. There is NO WAY exhaust pressure is going to by pass an open WG, just because it is flowing past it. The open WG is a LOW pressure area and will bump the excessive back pressure. Here is how my truck and MANY others are setup and it works great. This works on my 4.8 I had and now the 5.7 and also the high boost, fully built 403 motor in my buddy's truck.




I would try your boost ref line in another location and make sure there are no cut in it any where.

KissMySSo1

iTrader: (2)

Tial rated their 60mm waste gate springs wrong. A 5 lb spring might see around 10 psi +/- a couple lbs. A 10lb spring will be closer to 20psi. I'm not saying your gate location couldn't be a part of the problem. NLR is correct on his theory. Every setup works differently. On a very efficient setup with low back pressure; without the waste gate venting both banks of cylinders with direct flow, it WILL NOT regulate boost properly. So i would lean toward it being the gate more then anything. I have had the same issue with every Tial 60 i have installed.

When i had what Tial called their 15lb spring setup.(Big light blue spring along with small dark blue spring. I saw almost 30psi.

7845

iTrader: (1)

yes my gate had the 15 spring setup. and i was seeing the same results as you spoke. i currently have the 10spring but if its double makes sense why i seen close to 20 before i left off. ill pull the 10 spring and install the 5 see if that does anything

im still thinking of referencing from the intake

veee8

iTrader: (40)

Let me know if you want to get rid of the 10 psi spring.

NLR

okay your right.

I need to find a new job. Anybody hiring?

onfire

iTrader: (17)

Referencing from the intake will increase your boost not decrease it. It will add whatever pressure loss your getting from the piping and IC. Sounds like the gate spring is wrong.

If you're getting 15psi ref'd at the turbo and move the ref to the manifold, you'll pick up around 2-3psi...

kbracing96

iTrader: (25)

I've seen some of his logs and in non of them have I seen the MAP ever hit the gate. It just keeps climbing till he lets off. I agree, I think he need to put the 5psi spring in it and see what it does and go from there.

7845

iTrader: (1)

and think i thought the 10psi springwould solve my issues. Did Tial really mess up with the 60mm gate?

O btw this is using it with a PT88

NLR

Manifold pressure that keeps climbing with rpm is a tell tale sign of boost creep.

TiAL

oh dear...
yes it regulates pressure, and yes it matters where the wastegate is located. the gas WILL follow the path of least resistance, period end of story...having a 90* bend will always yield some creep - when the engine is in the upper band the gas does not want to make a 90 degree (or more) turn.

we ran a test on a manifold that was a top mount with a wastegate port that went straight down coming out of the middle of the collector...on a 2.0L and a GT35R we were able to make 16psi...yes 16psi of boost with NO wastegate, just a 44mm open hole...so yes it does bypass the wastegate.

that setup you posted is exactly what i was helping another guy with on OT...that wastegate position it horrid. first problem is it's only pulling of 4 cyl, the the closest bank to the turbo is free floating and uncontroled, the second problem is the 90* angle it's on. i can't see boost being controled at all.

this is how the setup should be set up for optimal control:
wastegate pulling from 8 cyl and directly in the flow path

TiAL

Our gates are rated with a 1:1 backpressure ratio (or force applied to the valve face) if you have poor positioning or less than a 1:1 backpressure ratio the spring pressure will change....i would guess in your situation it's the positioning if it's like that kit?. the gate is a mechanical piece, it works when it is set up proper, if there are leaks in the line etc you will see more boost...where are you taking the source from and what does the setup look like?

BigBronco

iTrader: (2)

Oh, Look who joined. LOL

TiAL

kbracing96

iTrader: (25)

I knew somebody was gona say this... This WG location has been hashed out MANY times on the truck boards. Bottom line, it works! With NO boost creep. The pic I posted is a kit that is on a 403 with a 44mm wg and a GT4202R turbo and has absolutly NO problem holding 8psi all the way to 6500.

Here is a screen shot from the OP's log that shows this is NOT creep, It just keeps climming from the time it start boosting till he lets off the gas. This is a tiny 4.8 with a big PT88 turbo. Your telling me that because the WG is in the cross over, that a HUGE 60MM waste gate will Creep??? I don't think so. I have a 38mm WG on a 5.7 with a T70 turbo and get 0 boost creep at 7psi. Same WG location.

TiAL

looks like it would do the same without a wastegate on it...i'm willing to bet you would get roughly the same results with no wastegate at all.

also that log....can you get me a TPS and Kpa log only? perhaps with numbers?

and yes, a 60mm would creep in that same location.

5.7 with a T70 and a 38mm? no creep and holds 7psi? not possible...unless you have a massive A/R or a boost leak and don't use an intercooler or redline at 4000 rpm

NLR

so take the wastegate completely off the exhaust and make a pull. Thats will tell ya right there what it is.

kbracing96

iTrader: (25)

TPS is in the 3rd chart, ref numbers are on the right.

Your right would look the same, cuz the WG NEVER opens


As for my truck, 5.7, as you can see 38mm tial, Master Power T70, P-trim, .68 AR and NO leaks!

I'm currently shifting a 5800, have ran it up to 6200 in this configeration.

TiAL

225kpa is what i'm seeing as where he took his foot off the gas....that is 30psi of boost....not 7

and in that chart 139kpa is 20psi of boost...