V-SPEC 1

I have this problem with my buddy's car w/ the afi topmount running t3/t67 high output ball bearing turbo. It has tial 44mm wastegate and it creeps to the moon. I put the smallest spring of 4lbs in the gate and still creep past 16 psi. SO I took the wastegate off the manifold totally, and made a pull on the dyno and the sucker still made 14 psi before 8000 rpm. No wastegate and still made boost. We're thinking of putting another 44mm wastegate on the manifold hoping it would fix the problem.

Bugermass

Manifold design these days is a joke. They are not keeping up with the improvements in turbine efficiency. As the turbines become more efficient, the exhaust wants to take the path of least resistance. Therefore if you do not have a properly designed manifold it will creep as it is easier for the exhaust gas to exit the turbine than it is the dump tube. If you want proof of this concept. Put some sort of restriction in the exhaust, say go from a 3in pipe down to a 2.5 at the tip, your creep issues will be greatly reduced or even completely go away. Anyone can make a cheap *** manifold. There are only a few that are actually designed properly.

a1320honda

Well...the story on the turbo is, the guy i got the journal bearing 6262 from ran a restrictor and -3 feed line on it its whole life. Talked to a tech at precision and he said that was a big no no. The 6262 smoked from the day i got it and was always a little stiff to turn by hand, it was supposed to only have 2000 miles on it. Pulled it off and pulled it apart to find out everything inside looks like its been very hot and oil was pouring out of the exhaust. I had on older Garrett 37R that sucked a rock in and chewed up the compressor wheel sitting on the shelf so I pulled the whole compressor side off the 37R And put the compressor side off the 6262 on it. its prolly not the best thing, but it will get me on the road with it. So for now till i can buy another turbo, im going with a precision/garrett lol. You can tell the bulk of the PTE and garrett parts were designed the same. Everything was straight forward and interchangeable. The measurements of the exhaust wheel are roughly 1mm smaller that the wheel on the 6266. My buddy was telling me about the 6235 is what gave me the idea. Dont have much to lose trying it out lol. Both turbos were worthless in their current state. I expect some lag but i dont mind lag.

As far as the creep issue, i already smoothed out the entrance to the wastegate and took that 1/8" lip down. Gotta pick up a restrictor that will fit the 37R oil inlet and have the exhaust V-band changed from 2.75" to 3" and i will have results posted.

a1320honda

I thought about picking up a buddies used top mount, but i really wanna try and make 650+whp with a ramhorn. Everyone in the spokane area has it in their head that anything over 500whp you need a top mount or forward facing.

Balor_Gr

No wastegate ang 15lbs.Wow.Anyone remember the Hytech turbo manifold wastegate placement?

TheShodan

iTrader: (14)

To a point Internally, the two companies are now very different from one another. Switching that compressor side with your turbine side without a full rebalance (unless you just forgot to mention it ) may cause more harm than good.

Precision's method of determining whether or not to use an oil restrictor has always been rather inconsistent. It really needs to go by oil pressure at the line of the turbocharger, and even then, only certain aperture sizes based upon that pressure. One tech will say "no-no-no", while another will say "yes, more than likely", but can't give any details as to which situation may fit. I get about 20PMs a week just on this question alone, and the answer is "it depends upon oil pressure", and because Precision and Turbonetics and Garrett are of similar design, I look towards the engine application as a guide, and go a bit more towards the Garrett standards for aperture size based upon oil feed location.

So may people say "I restricted it", and don't realize what size they ordered or used. When, in fact, it could have been too small and caused starvation issues. (look to see if the turbine shaft looks discolored or not.. that's a good sign to know whether or not the turbo has been restricted a bit too much.)

In addition, hot shut downs seem to be re-occuring these days on many setups, believing that just using the correct oil solves the problem, and people either are too cheap to get a turbo timer, don't set up the one that's on their alarm, or get too impatient with waiting in the car in additional minute or so before shut down. A sign of this is mainly a hot, or burned bearing. That gives more of an impression that the turbo was not cooled down more than any oil restriction. The problem is, you don't know if that's from the previous owner...or yourself. Hard to say.

I still think that the manifold design for many of these companies is just fine, its really more of a matter of people attempting to use one turbo to do everything given the surrounding equipment is just becoming more and more unreasonable. Using a 61lbs/min + turbocharger at such low boost pressure to utilize a boost-by-gear system just gets nasty. One can't have it all unless you either twin-charge, or understand that top end power or response may suffer for something smaller than 3 litres.

Its great that we're able to push the envelope on these setups, but they still can't beat the laws of physics..

Good luck with your turbo, hopefully, it works out.. I suspect an additional gate is still going to be needed, regardless, however.

Bugermass

I've seen properly designed manifolds hold 4psi of boost on 91mm turbos. It IS important. And it DOES come down to manifold design. Problem is people are getting cheap and are buying these $500-700 manifolds that are basically some pipes welded together with poor wastegate placement. It is what it is.. These companies that are cranking out manifolds at stupid cheap prices arn't doing the RnD to ensure that they function properly. And the consistancy between manifolds is very loose, so you may get 2 that creep and 2 that don't of the exact same manifold just because the welder angled it slightly different on two of them. It is what it is. Unfortunatly the market is flooded with these low cost manifolds so no company wants to spend the energy doing it right because they can't compete with the backwoods garage manifold builders who barely charge enough to keep their doors open.

OneBadTurboCRV

Yes, and there is a user on here that if still using that manifold.

TheShodan

iTrader: (14)

I still don't see some of the logic you are proposing. Are you saying its design, or materials? Because the same materials are being used for these manifolds (Schedule 40) and at the same time hadn't seen these issues for 10 years on similar turbochargers on the same 2.0 litre platforms. Be it Full-Race, SLS, AFI, Blueridge, Sheepey etc, ALL are using the same if not better materials for over the last 10 years, (sans CXRacing and others).

I could see this on some of the larger engine platforms for 4psi for a 91mm inducer turbo, using a LARGE gate over 60mm (which makes sense) but unless you're saying that "cheap" designs are based upon wastegate placement or some other configuration, I'm not following your logic here. If you could provide some specificity in your examples, we might be able to better gauge your meaning here.

Example is on 3:22 of the following video. (honestly, I'd look at the whole thing)

But this phenomenon is based upon more of the placement and relative use size of the wastegate, and not as much as the overall design, especially something as simple as a Kooks, which has been in use of that configuration for a bit over 20 years.

Efficient turbo + wrong wastegate size relative = Boost oscillation , creep or spike issues

Efficient turbo + Properly sized gate = better controlled boost operation for higher power bands.

As for the manifold design.

Take an AFI "Kooks" manifold for example on 2 projects I worked with recently.


1- AFI Kooks + GT3076R (52lbs/min) + 20psi of Pressure + 38mm MVS gate = NO Creep

2- AFI Kooks + Precision 6266 (66lbs/min) + 7psi of boost pressure + 44mm MVR Gate = Creep at 15psi,

And yet the creep is caused due to materials used? I guess I don't follow. That sounds more like mismatched wastegate to turbo to me.

a1320honda

Yeah when i pulled the turbo apart, parts inside where discolored and you can tell they got hot. And like i said, the thing from the day i got it was pretty stiff to turn by hand. It was run with a -3 line and a .035 restrictor. It was an AFI kit that im thinking came with a BB turbo and the turbo was swapped out in favor of the PTE and just used the feed line that was already there.

TheShodan

iTrader: (14)

Yep. that'll kill it alright. Especially on a JB version of that turbocharger. The problem with that is the discoloration compromises the ability for the turbo to rotate properly, as the shaft is essentially warped. So I'd save your money up and repair it properly, as putting your new wheel on without balance AND with a "Blued" shaft = trouble.

a1320honda

oh i forgot...you can see a slight bent in the shaft when spun at like 2000rpm. lol

OneBadTurboCRV

...Wow, and just what do you think would happen at 80,000+ RPM??? You would have a literal ticking time bomb on your hands.

"TheShodan" - I am not quite sure what your rampage is all about. He was saying design repeatedly; did you even read what was written? On top of this I have never had to use anything over Schedule 10 piping for manifold setups. Are you positive you meant standard Schedule 40 pipe? Quite a difference there.

Bugermass

No where did I mention anything having to do with materials used. Perhaps you didn't actually read what I said..

In the combined posts I have written I have basically stated that poor manifold design (which includes im-proper wategate placement, quantity and size) with newer high efficiency turbine wheels is what is causing the creep issues. Exhaust always follows the path of least resistance. It has nothing to do with intake manifold pressure. A properly designed manifold should be able to provide enough WG priority to allow even the smallest spring size to be effective without any creep. Regardless of turbo size. Yes with older tech wheels and smaller turbos the actual design becomes less critical as they naturally produce more pressure pre turbine thus the WG placment and size are less important to giving exhaust gas priority, But that is no excuse for a poorly designed manifold especially considering most people are not using old tech wheels and small turbos anymore. You can't ask a customer to run 20psi of boost all the time because you don't know how to design a proper manifold. These manifolds should be designed with the mindset that people are going to run these on the street and will need to be able to effectivly control boost down to 6-8PSI. Its really quite rediculous.

a1320honda

Well...got my Garrett 37R/Precision 6262 turbo in. Car feels amazing and is making boost 1200 RPM sooner with the bigger exhaust wheel. Still fighting the creep issue. 9lb Spring creeps to 15lbs by 9000. So its either live with it or 66mm Precision gate lol.

TheShodan

iTrader: (14)

I'm well-aware of what he stated, however, I still believe that his logic is flawed in its construction for the basis of his argument. After 20 years of that design being successful, I don't see how, "all of a sudden" the design is bad and the manifold is "cheap". You of all people know that items don't just "suddenly change". When purpose changes with that same design, there are going to be some hiccups. After seeing the last post, I understand his statement with a bit more clarity.

Waste gate placement taken into account, as a former Garrett engineering consultant, these newer turbos are efficient, but not THAT much more efficient. The original relationship still stands between waste gate placement, boos pressure desired and exhaust energy expounded. These turbos, (including any of mine) are not magic. They still follow the same laws of fluid dynamics as anything else.

And I stand corrected on the sched40 vs. sched10.. I mistyped.

Bugermass

A small restrictor in the exhaust will tame that boost creep down with a minor effect on power at your level. It usually doesn't take much, somtimes just putting a 1/2in to an inch smaller piece of pipe close to the end will do the trick.. Obviously at high boost and big power this is not a viable solution, but for the boost level you are running it would be fine. Also, having excessivly retarded timing can exaggerate creep issues.

Muckman

iTrader: (2)

That’s a picture of my Hytech manifold being built. I decided on the Hytech manifold during a time when Full-Race first started putting dual wastegates on their "Kooks" manifolds to control boost. And it was the same issue back then. Big turbo, big flow, unable to bypass enough exhaust to stop boost creep so this thread shouldn't be a shock to anyone. I chose the manifold with the most wastegate priority on the market to avoid these problems.

However now I feel the Hytech design is overkill for boost control and hurts top end flow because of the turbulence created in the wastegate neck area. Actually I would prefer a little less wastegate priority. It would help me combat boost taper and probably flow more hp. Clearly there is a happy medium somewhere.

B and B

iTrader: (3)

What? Shodan erred?
These truly are the end times..

reminds me of.. "I thought I was wrong once, but I was mistaken"
Good man tho, see? Steps right in and takes his medicine.

What is the relevance/history of this "Kooks?" please enlighten me
Only time I heard that name was headers or sumpn' spying on Mustang Forums...years of lurking in here haven't heard of it, and now it's scattered all over this thread?

wantboost

iTrader: (2)

Kooks built the first ramhorn style manifold iirc forever ago and everyone copied it

But look at the manifolds available today from almost every company. Every offering is an exact clone of some popular first offering from big name fabrication companies, even the eBay manifolds, all of them, follow suit with identical copies, right down to wastegate placement.

The car building game, and yes it really is a game at this point, anyone who feels/thinks otherwise is just lying to themselves, has gone from legitimate hard work to cookie cutter bolt on. There's no real effort in doing things anymore.... turbo kits bolt right up, you can buy complete turn key built motors, hell even engine management has become "bolt on"... there's no real work involved anymore. Anyone with the internet and money to waste can now point and click their way to 500 horsepower.

Hell I remember when people were awe shocked that companies like drag, Rev hard, and Greddy offered bolt on turbo kits and could make 300+hp... and when the safc was the defacto tuning method and ho people thought anyone that had to swap from an OEM map sensor to a GM 3bar was "pushing the limits"

A few people and companies strive to be unique, even fight and claw tooth and nail to do so, but that's a dying breed. Especially if a company gets a hold of a product and ships it off to China/Taiwan to be copied in bulk with little emphasis on quality, only the lowest price point seems to matter anymore

/rant

Balor_Gr

Imo that header design is great.Im thinking of giving it a shot soon.I believe you cant escape turbulencewith any wastegate design.If you think about it AT the normal 90 degree wastegate placement the hot gases hit a wall to escape to the wastegate.
And as we see it was used for serious racing...

wantboost

iTrader: (2)

F1 engines have such high VE for such small displacement, not to mention an insane ability to rev to the moon. So that means a lot of exhaust gasses for (what used to be) a single turbo (I have one laying around) the turbo technology was so advanced on the 80s turbo F1/Champ cars it still puts even today's most advanced consumer turbos to shame. We're talking titanium compressor wheels, investment cast titanium turbine housings, magnesium compressor housings, triple ceramic ball bearings, inconel 716 turbine shafts. They are so responsive it took massive wastegates with direct exhaust gas priority (like you've posted) to control boost pressures. Especially when you consider how fast the motor revved/responded to throttle inputs.

I still want to use that turbo on something lol

a1320honda

Well...here an update. Was gonna pick up a Precision 66mm gate to throw on the manifold, but ended up finding a guy that wanted to trade me his used older top mount for my ramhorn. the top mount had a 2 bolt 38mm gate on it so i took it as an opportunity to rework the wastegate setup.

Made some gussets to help with support


Then the wastegate..






Fits in the car perfectly...


Ill be getting the downpipe and dumptube reworked this weekend.

wantboost

iTrader: (2)

There is a considerable gain in lag time using a topmount over a ramhorm, like one that is measureable. At least heat wrap the manifold

And unless you're running sky high pressure levels, I honestly doubt the 38mm will be adequate.

a1320honda

The manifold was setup for a 38mm. I reworked it to be a 44mm. And ill definitely sacrafice a little lag to have the thing hold a solid 9-10lbs in the lower gears.