I'd appreciate any help from the experts...or anyone who has blown a turbo.
Help a Supra friend

I have an HKS twin setup, and I'm trying to diagnose my boost problem. The car will not make full boost anymore. The boost it does make has no kick to it at all.

I have done boost leak tests, taken the wastegates off and inspected them...even compression tests. Both turbos do have some shaft play. The front spins pretty freely, the second turbo is a little stiffer/not as free spinning.

This whole thing is driving me nuts. To replace both turbos will cost $4000...I'd rather buy another turbo kit.

Thanks for any help.


Scott

peace

 

y would u want to buy a whole new kit if the 2835 kit (which im guessing u have) is like 7000?

 

Scott, Why are you not posting on Supra forums? Next, How much boost are you making, and at what rpms? How does this compare to what you were making before? Are you using a stock ecu? What year/ If the car gets hot, or has some other problem(ignition/high knock/etc) the car will go into limp mode to protect the engine. Disconnect the battery for an hour(do not just pull the EFI fuses). Then run the car a couple of times. Either way, start with the basics(plugs/wires, ignition, fuel pressure,boost controller, VPC, etc) your turbos are probably fine. Carl Byck
97T RSP T66 Supra
88 FC Widebody TO4S

 

Well, you could try to get them rebuilt or try to find a pair of good used ones.

But an upgraded kit is so tempting. Depends on if you got the cash and want to keep the car for a long period of time.

 

I have asked this question a million times on the forums...no one ever answers it seems they just respond to simple questions like "what does BPU mean?" Or " what wheels should I buy?" The turbos cost $2000 each to replace...that's why I was thinking of switching turbo kits.

I'm not sure if there is anyone who will rebuild HKS BB turbos? Anyone?

I post under "The Pikey" on the forums.

Thanks for the responses.

Scott

peace

 

well i help diagonose a problem on my friends 300zx same problem with stock turbos... anyways car ran 18psi of boost but still seemed just as fast at no boost... you couldnt even tell when boost kicked in.... anyways 5 mis routed vaccume lines.... routed to the wrong things..... i dont remember exactally what but once we switched them around and put them in the correct spots... whoa.... thing ran GREAT

 

That's my second theory. I cannot control boost at all...even if I turn the controller off...it still does not run off the wastegates.

Scott

Peace

 

HKS DOES do rebuilds.....my friend has a T04R on his Supra and sent it back to HKS. They did a nice job too.

 

If they are ball bering a rebuild is a cartridge change...

 

This guy doesn't even know if anything is wrong with his turbos LOL

 

I have the answer to your problems. Sell your battleship and buy an RX-7. Boost problem is fixed

 

Disconnect the solenoid for the boost controller completely and just run a vaccum line straight to the wastegates, see if this helps. Your boost should be lower and slower to come on, I don't think the problem is your turbos. Unless something internally is catastrophically wrong with your turbos they should still make boost, I have seen turbos that were really on their last leg and they still made boost.

 

if you've already tried everything you can think of, why not take it to a shop w/ the proper expertise. there should be a few around you.

 

Trust me...I have pretty much exhausted all my resources. Whether it be forums or performance shops. I'm just trying to get as many possible(within reason) answers I can before I spend $2000(each) for turbos or a different kit.

My maximum boost has gradually gone down over the past few months. As boost comes on, it levels off real fast and stops pulling/loses thrust. That's why I would be surprised if it was the hoses...but I don't why I can't even set a desired boost level. I have switched out boost controllers, used MBC's, all giving me the same results.

The few times my car does have problems...they're usually gremlins that are hard to weed out.

thanks for the responses


Scott

peace

 

If you have no smoke, and you take the filters off, and the wheels do not touch the housings, the problem is almost certainly not the turbos. What is the max boost you can build, and hold in the manifold? Scott, have you posted on your regional supra forum, asking for a qualified mechanic? I just hate to see you buy new turbos before a good Supra mechanic goes through the car.
Jason, as for the battleship, bring your little PT boat a little closer
Carl Byck
88 FC Widebody TO4S
97 Supra T66

 

Scott, if you know your turbos are bad then I have your answer. Simply sell your HKS turbos for big money. I'm sure someone will buy them from you. Replace the turbos with something comparable with your hks turbos. I can get you any turbo you want for cheap. Hit me up if you are interested.

Eric

 

Scott,
Its time for me to look at the car. We will put it on the lift this weekend

 

I usually build around 1.3 to 1.4...but it does not feel like that much boost...the car falls on its face. That's usually in the 600+rwhp range for me. The reason I'm not 100% sure about the turbo's is...they have always had a little shaft play, but there is no noises coming from them.

Jason is mad because my battleship made it through a bad hail storm with NO scratches or dings...while all the local PT boats suffered heavy damage

Thanks for the offer Resource...going to take the turbo's off this weekend and have a closer look.

Scott

peace

 

Scott, let Jason look at it, it is not the turbos, really seems like a boost leak, or a timing/ignition issue. Are you using the stock ECU? Do not under estimate how much timing the ECU will pull if you have some other problem esp a 97-98. Good luck
That sucks about the hail, is that covered by insurance, or is it an "act of god"?

 

I have a G-force with an 8k rev limit. I really doubt if it's timing...I have made 779 on boost and 851 on nitrous, and I always run race gas...Lead/unleaded mix. I'm not sure what the symptoms would be if my HKS Twin Power went bad.


It would be much easier to explain if someone else actually drove the car to feel what I'm talking about.


Scott

Peace

 

I had the car on the dyno today, and it only made 450 rwhp at 1.8 and 1.9 bar...should be in the 720-740 range. Like it was only making power off of one turbo. It was spooling very late as well.

We let the car idle, then took the intakes off to watch the turbos spin..gave the car a little gas(then turned the car off) then waited to see which one would stop spinning first. The rear turbo stopped spinning almost a minute before the front turbo. It did not coast to a stop...it stopped spinning abruptly. I know it's not that scientific..but kind off odd.




Scott

Peace

 

i'd say start checking out those turbos....take 'em off and examine them, especially if one stops abruptly...might just have some damaged bearings...that could make a BB turbo pretty useless and non-fuctional.

other than that i say get a new kit.....change is good, plus i need someone to keep me motivated

 

The last boost problem I had turned out to be a bad muffler. Just a thought.