should i go Supercharger, or Turbocharger on my Leganza 2000

Daew0Leganza · Post by **Daew0Leganza** » Tue Dec 30, 2003 3:42 pm

going Externally Gated on a Leganza safest way or will a T25 Turbo Internally Gated be enough to keep the piston from popping out?

Post by **PrecisionBoost** » Tue Dec 30, 2003 8:32 pm

Blowing a piston out the bottom of your oil pan is a worst case scenario and it typically only occurs which you have too much power for the engine to handle. (boost set too high)

So to answer your question.... it make no difference.... both types of wastegates can cause severe damage if they malfunction.

The biggest thing you can do to keep your car safe is to limit your turbo size so that it provides the best mixture of boost vs spool up time.

For example lets say you want your car to run at 15 psi.

Ideally you want a turbo setup that is at it's peak efficency at 15 psi (mid sized turbo)

Some guys will throw massive turbos on their cars capable of 30 psi or more.....this is dumb...you never use that extra psi.... and the huge turbo takes forever to spool up so there is major "turbo lag" which leads to very low horspower numbers in the lower RPM range of the powerband

If you went with the ideal compressor and the wastegate malfunctioned it might jump it from say 15psi to 19 psi which may not kill your engine. (the smaller turbo runs out of wind at 19psi)

On the other hand if you had a monster turbo and the wastegate malfunctioned your pressure might jump from 15psi to 40psi which would most likely destroy your engine completely.

So the moral of the story is to go with as small of a turbo as possible while keeping the turbo efficency just inside your primary boost target.

This way you get the fastest spool up time (less lag) and more power throughout the entire powerband.

Most companies can supply compressor maps..... Sport Compact Car had a couple of really good articles about picking the proper turbo size and reading manufacturers compressor maps. (can't remember which issue)

Daew0Leganza · Post by **Daew0Leganza** » Tue Dec 30, 2003 9:16 pm

so wut is making the piston blow into an oil pan is the fault of a cheap wastegate?

Post by **PrecisionBoost** » Wed Dec 31, 2003 7:46 am

hmmm.... I'm guessing you don't have much experience with engines at this point..... I would suggest going to this site to learn about engines..... http://auto.howstuffworks.com/

Click on the top right " Power for the People: How Car Engines Work " and you will get a guided tour.

As well there is a section on turbochargers... http://auto.howstuffworks.com/turbo.htm

Ok... more boost = more power = more stress on engine parts.

The conecting rod is a metal arm that connects your piston to the crankshaft.

If you have too much power (accidentally push 30psi into your engine) your connecting rod will snap or the bolts holding it together will shear off.

At this point the piston is free to move around as it pleases.

When enough air and fuel get into the cylinder it gets ignited and boom it shoots the piston out like a huge bullet out of a gun.

With that kind of pressure the piston will smash against the crankshaft (most likely breaking it into several fast moving pieces ) and parts of the shattered piston will exit through the thin walled oil pan.

Daew0Leganza · Post by **Daew0Leganza** » Wed Dec 31, 2003 11:25 pm

so i should just get a T3 turbo with the smallest Trim?

Post by **PrecisionBoost** » Fri Jan 02, 2004 12:10 am

If I were you I would look and see what other 2.0L engines are using.

Hyundai has a 2.0L beta engine that several guys have turbocharged.

Acura's 2.0L engine (K20A) has also been turbocharged.

Nissan's SR20DET is a factory 2.0L turbocharged engine

Pontiac Sunbird 2.0L GT Turbo (the one I want to use) has a T25 from factory. ( I have the specs on it.... I will post it later)

Toyata makes two 2.0L engines....the 3S-GTE and the 1AZ-FE but I've never checked to see what they have for turbos.

If you want to make a good turbo setup it's important to see what everyone else has done.

Post by **PrecisionBoost** » Fri Jan 02, 2004 12:14 am

Oh and I just found a piece of paper that has the following writen down for the 2.0L turbo....

250 WHP was no problem with stock parts
At 283 WHP one of his connecting rods failed (heavy damage)
with new connecting rods this guy runs 350 WHP on nitrous with turbo.

I can't remember where he got the new connnecting rods...might have been Crower.

gti_7 · Post by **gti_7** » Fri Jan 02, 2004 1:40 pm

Sorry Erfinder, was that for the 2.0 pontiac turbo? or the nissan?

Thanks
Bernard

mocpac · Post by **mocpac** » Fri Jan 02, 2004 6:56 pm

Ok let chk this the mazda speed is 2.0 engine turbo. The hp of the car is just 175. My daewoo stock is 130. Here we have a 55 hp +. The protege is 131 hp stock (if I'm not wrong). Can we use the same setting?

gti_7 · Post by **gti_7** » Fri Jan 02, 2004 10:38 pm

okay.. the mazdaspeed is a real joke for a company like mazda to create. its a backyard "shade-tree" hack job at making a turbo car.

You could do a better job by your self than they did!

yes they had callaway do it.. but for the price.. no-im sorry no excuses.. the car handles on a dime, but with regard to the motor.. yuck!

why?

the mazdaspeed protege uses a stock NA block, pistons, rods. The tranny is also from a NA protege hence the lack of power.

The intercooler is very heat prone, and its from a diesel motor mazda uses in europe.

but wait theres more..

In order to avoid serious engine failure, instead of using proper forged internals, they [mazda] decided it would be best to run a 13:1 A/F!!!

the Garrett T25 runs at miniscule 6.5psi. its hardly worth the trouble to throw a turbo on there if your going to run that sort or pressure.

But your thinking. "I'll just crank the boost to 12" uh-uh.. fat chance.. the computer wont allow it.. even if you do it manually from the wastegate.. your going to end up with 2 inch holes in your pistons.. mazda even went with the 9 point compression ratio of the NA motor. they couldnt even lower the CR..

next..

The exhaust on the mazdaspeed is the SAME as found on the mazda MP3 protege.. why so bad? why run a turbo if your going to ask it to run through 1 7/8 piping!!

yes theres more to this rant..

"new" for 2003.5 are cheaper "no" suede seat inserts.. no "hart racing" shifter.. no fog lights but get this.. the price when up! they trimmed the wing.. and offer other colours.. blech i say..

sorry.. you want a real car? get an srt4 :twisted:

Bernard

mocpac · Post by **mocpac** » Fri Jan 02, 2004 10:55 pm

Clear enought. he he he....

Post by **PrecisionBoost** » Fri Jan 02, 2004 11:48 pm

Erfinder wrote:Oh and I just found a piece of paper that has the following writen down for the 2.0L turbo....

250 WHP was no problem with stock parts
At 283 WHP one of his connecting rods failed (heavy damage)
with new connecting rods this guy runs 350 WHP on nitrous with turbo.

I can't remember where he got the new connnecting rods...might have been Crower.

This was for a Pontiac Sunbird GT Turbo somewhere in the USA.

Post by **PrecisionBoost** » Fri Jan 02, 2004 11:57 pm

I personally thing 283WHP on stock internals is great.

If you want to convert that to crank horsepower ( such as your stock 130) just multiply it by 1.2 to get you about 340 horspower at the crank before you have something fail

Running 9 psi with the 8V head gives 165hp 175lb-ft of torque

Given the 16V Cosworth racing head seems to give an increase of 25% I probably wouldn't be too far off to guess that the stock Nubira head would give the car another 15% more horsepower than the 8V

So using this rough guess gives you about 190hp(at crank) and 200lb-ft of torque.

And remember that these cars don't have an intercooler!!!

So with an intercooler I'm sure it would top 200hp easily.

Post by **PrecisionBoost** » Sat Jan 03, 2004 12:01 am

gti_7 wrote:the Garrett T25 runs at miniscule 6.5psi. its hardly worth the trouble to throw a turbo on there if your going to run that sort or pressure. Bernard

You wouldn't happen to know if the T25 is a ball bearing or is it a sleeve bearing??

I'd really like to find a T25 or T28 ball bearing turbo but I don't want to have to pull one in from Japan ( SR20DET )

If anyone knows of an alternate ball bearing T28/T25 can you let me know.....thanks

gti_7 · Post by **gti_7** » Sat Jan 03, 2004 12:33 am

Erfinder wrote:
gti_7 wrote:the Garrett T25 runs at miniscule 6.5psi. its hardly worth the trouble to throw a turbo on there if your going to run that sort or pressure. Bernard
You wouldn't happen to know if the T25 is a ball bearing or is it a sleeve bearing??

I'd really like to find a T25 or T28 ball bearing turbo but I don't want to have to pull one in from Japan ( SR20DET )

If anyone knows of an alternate ball bearing T28/T25 can you let me know.....thanks

It is infact "the lastest" in ball bearing technology. I give'em that

Bernard