aLmk's Turbo FA5

[Si Speed 317]

For the record, boost creep and a boost leak are completely different. Boost creep is when you, for various reasons, make more boost than you're supposed to. Typically, this happens with improper wastegate placement. You're unable to get enough exhaust gasses to the wastegate, so more exhaust gas gets to the turbine and it creates more boost. Think about the scenario this way: you have a 7psi wastegate spring in your waste. In a perfect world, on wastegate pressure you will make no more boost than 7psi. Anything in excess of 7psi goes right out the gate; it keeps the gasses away from the turbo and out the gate. The more flow, the more the gate opens to compensate (like 1 person pushing a car, then 2 people, then 3, etc).

Now, lets say your gate placement on your manifold is less than ideal. You'll push the 7psi spring enough to open it through the gate, but not enough gasses are directed towards the gate so you end up with more gasses going towards your turbo than your gate, creating "boost creep". This is when you'll make more boost than the wastegate spring is setup for (i.e. 10psi on a 7psi spring, wastegate pressure only).

A boost leak is where you have an (or several) opening for boost to escape before the turbo. For example, a vacuum line or a tear in a coupler for your intercooler pipes. This will not allow you to make enough boost because of the leak. Its like having a hole in your pocket and some change falls through it. You can put all the change you want in your pocket, but some (of not all) will fall through the hole.

Hope I painted a good picture for you all

[aLmk]

Yea that is a perfect explanation. In my case I'm creeping from a 4 psi spring to 18+psi. Vit does not think it is wastegate placement as this is far more creep than any creepy manifold, and the previous owner had no issues which is still the mind boggling part.

And an update after tonight's work: it still creeps.

I did notice this while I had the wastegate/dump out of the car.

That is right where the dumptube sits next to and was resting on the downpipe. When I reinstalled it I did my best to clock it so there was some clearance, but the way the dump is shaped makes it quite difficult to get it in a good spot. But this makes me wonder if the dumptube resting on the downpipe could have caused enough pressure to make it not sit flat where it mates to the manifold, think that's possible? The clamp is fully tightened. This time it wasn't resting on the downpipe, but it is touching the subframe a bit, to do it proper and not have it hit anything I will need to lower the subframe completely to grind away at it some more, but I didn't have the time to do that tonight.

[Raizo777]

Nice build! I was thinking of going with a Precision 6262 before I went w/ the Kraftwerks Supercharger but I got a GREAT deal on it so I couldn't pass it up. Brand new, too! I'm throwing around the thought of switching to Full-Race Turbo. We'll see. I gotta get new wheels, front/rear conversion and changing the color of my car.

[aLmk]

Thanks. I don't have a 6262 though, I have a GT3076. If you do decide to go turbo I would seriously look at the PRL kit, they have a lot of great pluses in my opinion over the full race kit and the price is on point.

[Raizo777]

Thanks. I don't have a 6262 though, I have a GT3076. If you do decide to go turbo I would seriously look at the PRL kit, they have a lot of great pluses in my opinion over the full race kit and the price is on point.

Oh, I know.... I was just saying I almost went with a 6262 Turbo instead of Supercharging. If I do go with a Turbo it will be a while. I have more things to take care of first.

[aLmk]

Gotcha!

[aLmk]

When comparing these two pics:


I clearly see why Jay and Vit are such fans of the synapse kit/manifold. In my case I don't see why it couldn't be modified, I would just need a new dumptube, or perhaps modifications to my current one would make it work. Now if I were to have it modified like this, do you guys think the mvs (38mm) would be enough?

Also quoting this from the clubrsx thread about a guy experiencing boost creep on a full-race kit:

whats up guys --

i dont have too much time today to go into a lot of detail, but i wanted to give you some info on boost creep. Sorry if it doesnt initially make a lot of sense, there is a lot to think about --

An engine works by pressure differentials. A pressure differential is when one side is high pressure, and the other side is low pressure, so gasses move from high pressure to low pressure. Think of a balloon, all the air inside is at high pressure, put a hole in the balloon and they all want to escape to low pressure (atmosphere).

Boost creep occurs when the wastegate is fully open, but the engine is still making more and more boost. This means that there is a pressure differential that is so low, the gasses would rather go thru the turbo than a completely open wastegate. Think about that for a second -- when you use our turbokits the gasses would rather spin the turbo then go out the wastegate . Ever hear someone describe a turbo car as "bottled up" or "that thing needs to breathe". You will never hear that about our kits. This low pressure is why our kits make so much more power and spool the turbos so much earlier.. Full-Race manifolds are designed SPECIFICALLY to operate at low backpressure levels... because they breathe really well. Inhale, compression, ignition, exhale ->spin turbo fast. This is how we make so much power so easily, and on stock engines, Full-Race kits breathe into and out of the turbo better

You want to have the boost control of a log manifold? that is really easy, put the restrictor in your thermal exhaust. change to a 2.5" downpipe, put on a tiny turbine housing - litterally BOTTLE it up. Of course then you will be makes 70-80+whp LESS and dyno like a cast manifold setup like greddy or hks would make... have to set vtec later... lots of other issues. If you come to full-race you get a package that will outperform any other setup. If you want ultra-low boost all you have to do is order the kit with the upgrade to a 60mm wastegate, this is simply special order so it takes a little longer, but its a great solution. We do the same thing on all our B series headers for customers that boost creep.

if you have a 44mm wastegate and need better boost control, the small yellow spring is so light that it MUST be hooked up to an electronic boost controller or the turbo will be very lazy. The solution for this is to use an electronic boost controller hooked up to the TOP port (the side that says tial on it). The wastegate's side port should go to the intake manifold

regardless of wastegate choice, I strongly recommend installing a thicker head gasket (to lower compression) and ARP head studs. This allows you to boost comfortably higher and can save a lot of time and money since you really dont NEED to build the motor... but the 44mm is really better for 99% of applications anyway.

I find it interesting that he is saying his manifold is great because it makes the air prefer to flow through the turbo rather than the wastegate, but I don't understand why it can't be made identicle, just have the wastegate in such a way that it flows more nicly and allows the air to easily go out the wastegate while still retaining the low restriction of flow they have. To me the synapse manifold appears as though it flows just as well as the full-race manifold does (8th gen manifold) yet its wastegate placement and mostly shape allows for easier flow out the wastegate. Just don't get why full-race didn't also flip their gate around kinda like synapse. And when you consider a manifold like Vit's I can't imagine his flows bad or causes his motor to knock because the motor cannot breathe, yet he is setup to give the wastegate priority, not the turbo... :think:

[aLmk]

Alright this morning I put a vac t in the line that goes from comp housing to wastegate and ran a line to my boost gauge. I took video of the boost gauge while doing a wot third gear pull. I let off around 6500 or so when ot starts to really creep. Hopefully you can see the video, you tube says its still processing. And disregard the squeaky noise, that's just my clutch pedal.
Boost creep - YouTube
Thoughts?

[aLmk]

So for an update. Tried some more things past few days to no avail car still creeped a lot. This morning from 2-4am I put the car back together with the .5 bar white spring which equates to about 7.2 psi. Went out for a drive at 4am did a pull and it creeped just as it did before, I was getting 41* IATs. Now I had already planned to go up to the shop that did my last install today after hours to have him take a look at it and basically just make sure I'm not a blind idiot because at this point I had literally tried everything to troubleshoot this issue, and on the way there it didn't boost creep and with Bill in the car with me. quite mind blown....
I am so ******* mind blown right now it isn't even funny. I have no idea why it is working now. The car sat in my driveway all day, I didn't even drive it to class today, had my gf drop me off and pick me up, I get in it today at 5 do a pull to redline and no creep! Did another with bill in the car, no creep! Did another on the way home, NO CREEP!!!! WTF@!!!
But I do have another slight issue at the moment, its making a goofy rattle noise at around 2800-3200 usually on decel if in gear, and it didn't do this last night. I took a video of it, I'm sure its something rubbing, but I seriously don't want to touch anything because I may just cause it to start boost creeping again

[monjarassi]

well its a good feeling it fixed itself