How would I be able to tell what turbo I have on my 85 volvo 740? Which one is better to have for more power and reliability? Whatever turbo is on there It seems to spool up pretty fast with alot of power at low rpm's but at around 3000 rpm's (just a wild guess, haven't really paid attention to exact number) it seems to have no power. And when you get to about 4000 rpms the tach moves so slow. The boost guage shows high boost but must be beyond where the turbo can make power. I have adjusted my waste gate so that the boost goes just to the red line on stock boost guage (gonna give more boost after I fix oil leak on oil return line), I took factory air box out and put a cone filter in its place, and I added an aftermarket bov to run along with stock relief valve. So im just trying to figure out some easy cheap ways to get more top end. anny suggestions?

Well I got my gaskets to stop my oil leak from my turbo oil drain line. I just have to do it now but it sucks that it took until today for the parts to show up instead of Saturday like it was suppose to be. Now I have to wait until Saturday to do it because I get off work at 11 at night. I always have problems getting my parts on time. So when i do that I am gonna turn my waste gate a couple turns for just a little more boost.

I think I'm gonna get another intercooler line and take that bov off because that thing is cursed or just a bad idea to add. I have vacuum running to the stock valve with stock lines but I "T" off it to run a vacuum to bov. So now when I put my foot to the floor I hear the turbo spool up and then a loud air suction noise from my air filter. And when that happens total power loss and a wild bucking ride and then a couple of seconds later I rocket out of there stuck to the back of my seat.

I dont know whats going on, I have been driving a couple of days trying to figure out what that noise is and I think I got it. It has the same sound as my stock valve when it opens and relievs pressure. But instead of woosh you get a wooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooosh that you hear building up pressure like a rocket engine. So I am wondering if by running two valves off that one line is causing my stock valve to stick open under boost instead of keeping it shut under boost, like my vacuum is reversed? Is that possible?

I'm just trying to get a "to do list" So i can try and do it all Saturday

Sounds like you have a Garrett Turbo, which I've heard does drop out on boost at higher RPMs. That doesn't mean you have a healthy system otherwise.
My car has a Mitsu TD04 and only puts out more oomph (The boost is the same) up to 5300rpm.

--Tada--
http://www.brickboard.com/FAQ/700-900/EngineTurboIdentification.htm

Check those out.

While the topic is up, I would DEFINITELY get rid of the cone filter, especially if it's a filter you "oil" like a K&N.
The stock filtration is much, much better and a cone filter is going to kill your engine life, especially if you live in a dusty area. If you want better airflow, figure out a way to chop the stock box - it also already has a "cold air intake" through the fender, but I guess you could improve it with some large ducting out the bottom of the bumper.

Good Luck,
Will
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1990 740 Turbo, on its way to stock specs, maybe beyond

Ok so should i try and find a TD04 turbo from a pick and pull. There is a newer car i think it was a 95 850 something like that, i think it was a v6? I know it was front wheel drive. Would that maybe have a better turbo? I wll put the old air box back on. I have to check the timing because i replaced to distributor two weeks ago, that could be one of my big problems. I'm gonna fix my oil leak if my parts come here Saturday like they are suppose to. I'm gonna adjust my waste gate to get a little more boost, its gonna be a busy weekend. And when I get my boost up I hear what sounds like an air leak over by my air filter and stock bov. Could that be because I left my stock bov on or whatever its called that recirculates air back to intake but I have the vacuum line disconnected because I have my new bov running to where that vacuum line went to at the throttle body. I dont really understand what the vacuum line does. Does it keep the valve closed during boost, and so with it not hooked up my boost is just opening up the valve causing a leak? I am gonna hook it up I just cant find my vacuum T that came with my bov kit I think my little girls probaly got it. My car will start to surge under boost sometimes, not all the time. And that started to happen after the bov install and distributor swap. Sorry for sounding so dumb about the whole turbo setup this is my first turbo car, I paid 500 dollars for it and it only has around 136000 miles on it so I'm just playing around with it because it is only my commuter car just to get to work.

Wow, nice price:

okay, so here's the simple breakdown:
CBV - the thing you disconnected the vacuum line from (it's on the front side of the turbo and connects to the throttle body) - it opens a valve so that when you let off the gas, it reduces the boost by dumping the boosted air back into the turbo inlet - it way increases your turbo life and reduces strain on intake hosing. Some turbos (like on subarus) use blow-off valves (BOV's) and vent that atmospheric pressure to the air (you can hear a lot of new subarus whistle when they shift). The BOV setup doesn't work well on these cars because it will tell the car it's getting X amount of air, then when the car injects X amount of fuel... Bad things happen.
It works fine on cars with MAP sensors, And I think that your car has a hot wire sensor in the airbox top... What did you do with the electrical connector that went to the top of the airbox?


Wastegate - it regulates boost by opening a valve once the boost hits a certain level. When it's closed (or at 0 boost), the valve is all the way closed, and it's pushing all the exhaust (or maximum) through the turbo. When it opens, it reduces the amount of exhaust spinning the exhaust side of the turbo.
If it's broken, you can get surging, no boost, or overboost.


Anything more, you may want to read up in the turbo faq and check out www.howstuffworks.com I'm off and I'll post back later.
-Will
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1990 740 Turbo, on its way to stock specs, maybe beyond

ok well is it ok to run both at the same time? I am only running both because I had to cut a piece out of my intake in order to install my bov but, I dont know if i like or trust it and cant uninstall it unless i get a new intake pipe. So i decided I might be better off running both. As far as my air filter set up I still have the sensor hooked up i just unbolted it from the air box and after you remove it hook it back up to intake hose and put a filter on the other end with a hose clamp. Now I have a question let me see if i can explain it because I cant get pictures to upload. Well there is a black knob on the bottom of the throttle body that you can turn in and out and I thought it was something loose when i saw it so i screwed it in. I heard a change in how my engine was running so i tried to put it back how it was but i dont really know where that was. What does that knob do, it sounds like it changes the throttle body air pressure or something. I drove around adjusting the knob but I dont know what it does but it seems like it might be important to get adjusted right. And thank you so much for your input, I have always wanted to own a turbo car and now that I have one I would really like to understand everything about them. I have taught myself evarything about cars by trial and error and from people like you giving me input, so thank you.

Sure, we're glad to help. *ahem* I always try to read before I mod... lol. anyhow, trial and error does work, but moar boost can lead to moar engine replacement, etc. etc.

Also, can you space your posts out a little more? It's a little hard to read, but anyway.
It's good that you have the sensor installed inline with the filter - it's the Air Mass Meter (AMM). I'm not sure if bosch/regina matters or applies, but I think the BOV will screw with the mixture. Basically the Bosch setup expects a closed system from the sensor to the throttle plate and a BOV opens it up. I dunno how it would actually work out to have both in place....

Okay, is this black knob attached to the throttle body and throttle plate?
Does it have a flat spot for a wrench in the middle, a plastic ball joint on each end, and a lock nut for each end?
If that's it, it's a link between the throttle spring setup and the actual throttle plate (anyone, feel free to correct me, I'm only about 70% sure that's the exact function, I haven't looked at it for a while). Adjusting it may adjust your idle (or not - the idle system may be able to compensate, depending on how far it can be adjusted and if the idle system works). I believe it adjusts where wide open throttle on the spool relates to the actual throttle bein wide open or slightly closed, etc.
So, if you make it really short, it may make the throttle plate only open 80% at wide open throttle. (I believe that once you're past about 1/2 way open, it's less and less important how far open the throttle actually is.)

Anyway, keep them coming, I'll be back tomorrow. You can adjust the link a few ways, but maybe someone else can chime in. I think both ends have the same threads, so tightening the middle might do nothing... then again it's 2 am (1 am with daylight savings time switch).

Night,
Will
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1990 740 Turbo, on its way to stock specs, maybe beyond

You may have some blockage building up in the exhaust system. Put a vacuum gauge on the intake manifold and run the rpm's up to around 2500 or so. If the vacuum drops much below what it was at idle then you've got some blockage or maybe an intake leak.

Should be a data plate on the turbo.
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