Turbo sizing discussion

[Stevebsy]

I found this excellent turbo calculator here:
http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml

I plugged in the following numbers:
Altitude 50 ASL
Bore 96.9
Stroke 75
Cylinders 6
Comp. efficiency 75%
Intercooler efficiency 70%
Boost 7 and 12 psi
Volumetric efficiency 88% (Per FSM Section 2.7 Figure 8)
RPM 6500

Then plot on the graph and according to the graph, my best choices are, according to the efficiency of the turbo:

GT42 w/ 102mm .60 AR
T70

7 psi:
http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml?FeetASL=50&Tamb=21&Bore=96.9&Stroke=75&nCyl=6&RPM=6500&VE=85&Boost=7&Ec=75&Eic=70&PdropIC=0.5&TambIC=21&wiPercentMethanol=50&wiRate=100&wiTemp=21&SFC=0.49&AFR=13.3&maxInjectorDutyCycle=85
12psi:
http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml?FeetASL=50&Tamb=21&Bore=96.9&Stroke=75&nCyl=6&RPM=6500&VE=85&Boost=12&Ec=75&Eic=70&PdropIC=0.5&TambIC=21&wiPercentMethanol=50&wiRate=100&wiTemp=21&SFC=0.49&AFR=13.3&maxInjectorDutyCycle=85

Just pick the turbo from the list below the numbers to see the graphs

Thoughts?

[Phast SVX]

uhhhh. Am i the only one that sees a huge problem here.
phil

[Stevebsy]

I guess so :p

What's wrong?

[oab_au]

I guess so :p

What's wrong?

Don't know about the turbo stuff, But the VE is too low.
Volumetric efficiency 88% (Per FSM Section 2.7 Figure 8)
Steve that dia. shows the air pumping capacity of the engine. The picture changes when the engine is actually running, and the exhaust action is working. It gets to 104%.

Harvey.;)

[Stevebsy]

If that is the case, the T76 looks like the winner, at 7 or 12 psi.

http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml?FeetASL=50&Tamb=21&Bore=96.9&Stroke=75&nCyl=6&RPM=6500&VE=104&Boost=12&Ec=75&Eic=70&PdropIC=0.5&TambIC=21&wiPercentMethanol=50&wiRate=100&wiTemp=21&SFC=0.49&AFR=13.3&maxInjectorDutyCycle=85

[cdigerlando]

Sounds about right. I am running a T3/T4 garret hybrid with a 60 compressor wheel. It seems to work well. So when does it go in?

[Phast SVX]

If that is the case, the T76 looks like the winner, at 7 or 12 psi.

http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml?FeetASL=50&Tamb=21&Bore=96.9&Stroke=75&nCyl=6&RPM=6500&VE=104&Boost=12&Ec=75&Eic=70&PdropIC=0.5&TambIC=21&wiPercentMethanol=50&wiRate=100&wiTemp=21&SFC=0.49&AFR=13.3&maxInjectorDutyCycle=85

I had thought u already started twin turbo setup
That turbo will spool very slowly. It definetly will not make good usable street power. Go with a large t3/t04 or 60-1 t4

phil

[Phast SVX]

Example: my turbo on the left, GT42R on the right.
http://www.k20a.org/pacman/Gt42r%20003.jpg

Also, Here is a picture of a gt 42R on a supra..... a 1300whp supra ....
http://us.st11.yimg.com/us.st.yimg.com/I/wotmstore_1921_36698205

[cdigerlando]

Wow that is huge :eek: Yes you might want to start out a bit smaller unless you plan on lowering your compression and building the engine.

[cdigerlando]

This is a pretty neat application.

[svxsubaru1]

After reaserching and opinions from others on this board and others i always thought the garret gt35 trubo would probabley be one of the best options for the SVX, but due to cost it was never really an option. After reading a nasioc thread http://forums.nasioc.com/forums/showthread.php?t=1094234 it looks like the performace characteristics could be achived with a much cheaper tubro (eaby less than $300). The turbo is a holset hx35w which is from the dodge diesel truck. I havent been able to find a efficiency map yet so if any one can that would be great.

[92svxinmn]

dont know anything about the holsets but diesel turbos are very laggy, had a tp38 on mine and was sloowwww .84ar turbine even. seen a gt40 on ebay for 350 buy it know, cheap aint the wait to go on a turbo.:)

[svxsubaru1]

After reading about it on nasioc and a bimmer fourm it sounds like it prforms like a 35r which is not the least laggy turbo but it wouldent be bad on a eg33. A person on nasioc was hitting (8-9 PSI no tune) by 4200 RPMs on a ej257. The eg33 should easily have it spooling with its extra .8 liters and high comprsion engine in the mid low 3K range. The only thing is that holset doesnt give out any efficincy maps. So it would be a shot in the blind to even see it would preform at around 10 PSI. Just becasue its cheap doesnt mean its bad, iam sure if the gt35r was on fairly large scale production vehicle they would be alot cheaper.

[svxsubaru1]

http://s57.photobucket.com/albums/g221/dukeduster/?action=view&current=TurboSteve.flv

http://www.dsmtuners.com/forums/attachment.php?attachmentid=44446&stc=1&d=1104971598

A person posted up a map for it on nasioc. Pre-2003 HX-35 is in Green. 2003 - 2004.5 HY-35 is in Black. 2004.5 Present HY-35 is in Red. He said he had some better maps that would be posted later.