wanting a bigger turbo for a 1.9 td

[cadmo]

Hopefully someone can help me out, I want a bigger turbo for my car

   On my car I did Smog's DIY 1.9 post, added boost and EGT gauges, a K&N air filter with holes in the air box and a manderal bent pipe instead of the ***ty one from the air box to the turbo, and an intercooler from a Mazda 626 or Mx-6 I cant remember, but Im thinking about getting a intercooler from a Volvo 740 or a Sabb 900 (much bigger), also thinking about O ringing the head for more boost. But.... I still have the factory exhaust seeing I was waiting to get I bigger turbo I didn't want the hassle and cost of building another down pipe.

   Anyways i've herd of just putting on a 1.6 turbo and hybrids (but hybrids of what haves) , im looking to make full boost around 2500 to 3000 rpm and pull hard to 5000 rpm with as much boost as the motor will take without distroying its self on our school dyno and seeing im a student (automotive course) money in kinda tight is there any other cars with turbos that would work

thanks for anyone that can help

[Dr. Diesel]

http://vwdiesel.net/phpBB/viewtopic.php?t=632&highlight=

http://vwdiesel.net/phpBB/viewtopic.php?t=398&highlight=

[AntonUK]

But why do you want a bigger turbo?? Is it because of smoke?? You will have a lot more lag it will full boost allot later giving less power bandwidth since the governor will be doing a fab job of reducing fuel at 4k or so anyway. Iv got a T25 on my 1.9TD and I hate the lag on it. I’m running around 18 psi, full fueling and IC and it makes very little smoke under WOT. I bet a smaller unit can handle that and be a lot more responsive in lower revs.

[Dr. Diesel]

there's a little more lag on kris's 1.9L/k24, but nothing that can't be eliminated with a change in launch technique. I'd recommend the change to anyway wanting more than 10 psi on an AAZ engine.

[cadmo]

Oh sorry guys I forgot to mention I did the govener mod and the reason I want a bigger turbo is more air = the more fuel i can dump in

[cadmo]

I also forgot to ask about boost controlers.  I dont want to get a ricer one that make a big swoosh every time i let up to the throttle.  What can be made to regulate the boost higher than the stock 9 psi on a K24

[web]

ok...

1) to raise boost, you do NOT immediately need a bigger turbo

2) ricer-swoosh is a blow off valve sound which is impossible on a diesel even if you wanted it.

3) boost controllers raise boost and are NOT the same as blow off valves.

I suggest you read up on turbo engines and how they work before messing with it!

[fspGTD]

Hmmm... let's see, why would someone want a bigger turbo on their 1.9lTD... I would think to lower EGTs!

EGTs with the "mini" turbos (IE: 1.6 eco-diesel turbo or 1.9lTD) get pretty hot after raising the boost and fueling a little bit, don't they?

Besides raising the potential for melting pistons, high EGTs in the presence of intercoolers and big exhausts indicate that the compressor is not operating very efficiently - putting a lot of heat into the intake and requiring a lot of power to be supplied from the turbine, and the turbine probably is not designed to provide that much power and so at the high airflow rates causes a big restriction in the exhaust, which makes the engine operate less efficiently (more backpressure during the exhaust stroke saps power from the crank).  So at high RPMs it seems that the mini turbos cause a power and efficiency loss vs the big turbos.

Granted, there are definitely other factors worth considering, but big turbos do have advantages... IE: even if you can get a mini turbo to put out a lot of boost, it will probably be doing so at efficiency and ultimate power robbing cost of high backpressure.

[cadmo]

Yes that was perfect I couldnt have said it better my self.  Because at a little over 3000 rpm my car falls flat on its face and wont rev worth a ***, well maybe thats a little extreem it just wont pull at all ( like a motorcross bikes power band, in it its awesome, out of it its a dog).  

   Last night I calculated my engine's needs and therefore my turbo needs and then went on the net and typed in compressor maps on google, to try to find out what turbo will work.  Right now I cant find the paper that has the out comes on it for the turbo (I will post them later tonight) but I ran into problems on all the maps, for air flow they all use pounds per min. or sec. and through my caluclations I ended up with cfm.  Now how do you convert to pounds per min. or sec.

   Also I just starting to think into the future or to solve the the turbo heat problem.  Has any one tried water injection or a 50/50 water alcahol mix?  I have friends that use it on drag cars and I know diesel tractor pullers use it.  So that might be my next experment once funds prevail.

   Well I couldnt wait, I got my girlfriend to look and call the numbers in they are 2.4 to 1 pressure ratio, 163.23 pressure flow through compressor and she thinks she found the pounds per min (it was late when i did it maybe I missed it) its 11.25  or that = .1876 a sec.

[fspGTD]

Yes that was perfect I couldnt have said it better my self.  Because at a little over 3000 rpm my car falls flat on its face and wont rev worth a ***, well maybe thats a little extreem it just wont pull at all ( like a motorcross bikes power band, in it its awesome, out of it its a dog)."

That is interesting to hear.  But answer me this: are you sure it's the turbo limiting the powerband and not the governor?  If your car usually smokes smoke at WOT, look at the smoke coming out the back of the tailpipe or have an observer do this from outside the car as you drive it.  Does the smoke stop as the power drops off?  If so, the power is being limited a lot by your governor reducing fuel.

Last night I calculated my engine's needs and therefore my turbo needs and then went on the net and typed in compressor maps on google, to try to find out what turbo will work.  Right now I cant find the paper that has the out comes on it for the turbo (I will post them later tonight) but I ran into problems on all the maps, for air flow they all use pounds per min. or sec. and through my caluclations I ended up with cfm.  Now how do you convert to pounds per min. or sec.

   Also I just starting to think into the future or to solve the the turbo heat problem.  Has any one tried water injection or a 50/50 water alcahol mix?  I have friends that use it on drag cars and I know diesel tractor pullers use it.  So that might be my next experment once funds prevail.

   Well I couldnt wait, I got my girlfriend to look and call the numbers in they are 2.4 to 1 pressure ratio, 163.23 pressure flow through compressor and she thinks she found the pounds per min (it was late when i did it maybe I missed it) its 11.25  or that = .1876 a sec.

According to http://cybrina.mine.nu/MR2_Docs/compressor_flow_maps.htm looks like they take CFM and divide by 14.27 to get pounds per minute.  Where they came up with that factory I don't know, I looked up the specific weight of air at atmospheric pressure, 70 degrees F and it was something completely different.  :?

[cadmo]

ya after checking again, that figure i got seems wrong like you said.  I found a program on the internet that does all the figuring for you and then you can pick from a list of turbo maps.  Ill write back one i get it