Chebosto

iTrader: (43)

one is volumetric flow rate, the other is density

Chebosto

iTrader: (43)

Here are the PE1420 Turbo Specs..

Compressor Wheel:
inner Diameter: 45.5
outter diameter: 60.0
Number of blades: 6+6

Turbine Wheel:
Outter Diameter: 48
Exhaust Diameter: 44.0
Number of Blades: 8
Shape: Slanted FLow

Ball Bearing. Valve Bore is 23.0

the Name PE1420 means, that the Max FLow amount is 14 m^3/min, A/R is .20 (i think)

as far as A/R goes.. with a low A/R ratio, the turbine will spin up quicker, but as engine output and rpms increase, the restriction of the housing begins to build up too much back pressure on the engine, which reduces performance. a larger A/R ratio will improve your engine's top end, while losing some mid range power and increasing turbo lag. A smaller A/R ratio will help the bottom and mid-range, but may effect the top end.

looks like my PEs make better mid/low range.. and the top end probably isnt as good as it could be..

so Slay.. you make the decision.. on what is more efficient..

EDIT:

looking around on the net, since PE USA's website sucks ***, i had to goto IHI's webpage.. they have soem charts for their turbos, and since i know the max flow amount is 14m^3/min..

i'm assuming that the PE1420s are the RHF55 on this map-- purple... or something close to it...



more..

SQUILL

1 LB/min=14.472 cfm

SQUILL

ok 1.6 bar on the chart is 1.6 atmospheres or our normal atmosphere of roughly 14.7 plus an addiotional atmoshpere of .6 which equals roughly 9 psi of boost so 9 psi of boost is 1.6 on the chart.

now to determine cfm requirements for the turbos

so take out engine size in cid 213.5 x rpm lets say 6500 =1387750 / by 3456 = 401 cfm

this would be the na cfm consumption at sea level 401 cfm so then at 9psi or .6 bar our effective engine displacement is 341.7 cid use the same formula and we need 644 cfm for ease of math

so each turbo will need to flow 322 cfm to @ 9 psi so go to the charts and line up 322 cfm with the 1.6 line in the charts and this shows where the turbos are in their efficiency range @ 9psi

SQUILL

ok it will be easier to see like this i marked the spots on the charts in red

SQUILL

here at 6psi you can see the smaller garrett turbos are happier running lower boost than the big td05 18g greddy turbos which would prefer to live at the 16-18 psi range for max efficiency while the garrett turbos in the .60 ar trim would like to be in that 12-14 psi range for max efficiency.

SQUILL

and the finally here is a flow chart based on the nissan VQ35de the numbers are rounded to keep it simple you can get an idea where these two turbos like to be for this engine .. the math isnt perfectly precise however this is done for ease of math and is very close to give u guys an idea. U can see how the greddy turbos will offer great room for expansion on built motors where as the skidazzle turbos are more closely matched for the stock motor based on this data i believe that on the same dyno skidazzales car will lay down slightly more hp at the same psi boost level than the greddy will and again i believe slightly probably 10-15 hp ...will anyone test this theroy???

Mr B

iTrader: (2)

I have to say... awesome work Squill. This thread is badass!

SKiDaZZLe

damn squill... still trying to digest it all, but that is a pretty cool explanation!!!

m

lacartus

Nice graphs SQUILL, I appreciate you taking the time to put those together.

Here's a link to the Garrett Catalog (not sure if it's the latest) that shows compessor maps for their other turbos. We should also be able to view it at http://www.turbobygarrett.com/, but I was getting an error when I tried to view it.

Drag Limited

60-1 turbo @ 15psi on a SR20DET made 400+ hp
T25 turbo @ 15psi on a SR20DET made 265 hp

you be the judge

SQUILL

You know i should have stretched the garrett compressor map out to the same size as the tdo5-18g chart so the differences could be more clearly seen.

The tdo5 18 g's are really running in the sweet spot in the higher boost levels i think these turbos are going to power some monster built motors in the future quite well.

The intercoolers of course are helping to reduce the inefficiencies of both systems as well but the only thing that i dont know between skidazzles system and the greddy is intercooler pressure drop and cooling performance as well as the overall flow characteristics of the plumbing in both systems.

All things being equal in the lower boost stock motor applications (5-10 psi) the garrett turbos are running closer in their efficiency range for that level of boost than the td05-18g's are abeit this may not make that much difference in max hp at any given psi setting however i would therorize the responsiveness of the garret turbos is probably very quick and the powerband they produce is probably beginning slightly eariler in the power band than the bigger greddy turbos.

Back to the PE turbos which have similar qualities as compared to the garret turbos being smaller and quicker spooling this is why the Pe system SHOULD run a higher hp level than the greddy system when you are comparing the systems at a fairly low boost like 5-or-6 psi where the Greddy tdo5-18g turbos are barely on the brink or the efficiency curve.

Again how much more horsepower is entirely subjective as timing and tuning can vary by so much but even if things were equal i would have to guess maybe a max of 20-25 hp @ 5-6 psi as a difference however as the boost in increased the greddy td05 18 g's they start to really perform better and i would bet the greddy kit running 9-10 psi is a monster with insane torque response and spool time.

Of couse comparing peak hp to peak hp doesnt paint the real world picture of in car performance but it is fun to sit down and analyze things like this.

I would love to see someone post dynos of a PE system for gods sake!!

Skidazzle im curious if you dynoed with a greddy car on the same day @ the same psi setting???

Also remember the PE turbo and the Garrett turbo are smaller Ball Bearing turbos and the Greddy Turbo is slightly larger with standard sleeve bearings.

The PE system and Skidazzles custom Garrett system should out perform the greddy kit in responsiveness and the powerband should be a little broader and begin sooner in the revs. The differences will be small but this is why the PE system should be able to claim a slightly higher hp figure for the lower boost settings.

slay2k

Once again, when you say "5-6 psi boost"... psi WHERE... BEFORE it gets into the engine, right ? Before the turbo, right ? At the inlet ??

SQUILL

Psi should be measured as positive manifold pressure or at the inlet. The most important difference being what cfm of air is being developed at any given psi per turbo for example if you have a turbo that is producing exactly 1 bar of boost with exactly double the cfm that the engine requires in N/A form what you have effectively done is turned your 3.5L motor into a 7L motor.

Now if you are running The same 1 bar of boost with a turbo that is not quite running in its efficiency range and or simply can not flow the necessary cfm that is demanded of it thus not being able to produce the necessary cfm requirements you end up with a smaller motor for example if the engine requires 800 cfm of total air at 1 bar but you only supply it with 700 cfm you wind up with a 6.1 L engine.

The closer to the efficiency the turbo is running the easier it is to meet or exceed the cfm requirements of the motor at any given PSI level throughout the rpm band.

Trent@MVP

PSI is and should always be measured at the intake manifold. Your turbo or turbos are always going to be making more psi than your motor is actually seeing. This has to do with IC piping, the effeciency and pressure drop of the IC itself, as well as the overall effeciency of the turbos themselves.

Yes 6 psi is 6psi. But saying that two totally different turbos at the same psi are going to make the same power is ridiculous. There is no way they will make the same power, assuming all other factors being the same.

I've done this on my personal vehicle. Toyota Supra. The current setup I have makes 540rwhp at 16psi on pump gas. I put a much smaller turbo on there to do a little road racing and had it tuned prior to going to the track. Everything else on the car was the same. We only swapped the turbo. At 16psi on this smaller turbo, I only made 430rwhp.

This all goes back to the compressor maps, the volume of air, the density of the air, and how hard the turbo is having to work at a given psi level. My larger turbo at 16psi hasn't even woke up yet. It's effeciency range is 21-25psi so it's not even really working that hard yet.

slay2k

Cool, thanks for clearing that up. Damn I need a Supra =|

SQUILL

Exactly @ 16 psi the larger turbo is able to flow significantly more cfm @ 16 psi than the smaller turbo which of course equates to a larger displacement engine overall.

My therory as to why the PE system makes more hp at the lower settings like 6 psi for example is that the Big greddy turbos are barely in to their effeciency range and are not flowing as much cfm as the smaller PE turbos are as they should be spinning faster and flowing more air freely than the greddys do at the low 6psi boost pressure.

As the boost pressure is dialed up i believe at 12 psi and up the greddy turbos will simply dominate the PE turbos in CFM output.

I dont have a compressor map to analyze for the PE turbo but based on all the info ive read about them i believe that the turbos that skidazzle is running should be fairly similar.

If i remember correctly i believe the Pe turbos will max out at about 500 whp or so.

Sharif@Forged

iTrader: (92)

great discussion...thanks Squill!

So at 12psi, the Greddy TT appears to be clearly in the sweet spot of efficiency...right? Even at 9psi, it's getting pretty darn close.

SQUILL

Yea actually those garrett turbos on skidazzles car flow a little more air than the Pe turbos do if i remember correctly.

By 9 psi i would theorize the PE and Greddy kits would generate similar peak HP numbers on the same dyno asumming both cars were tuned to their max potential.

I hope someone can test out this therory by doing it.

At 12 psi you can see there is much more cfm left out of the greddy tdo5-18g's than in the gt 28's.

This would allow plenty of room to bump the rpms up on a built motor and still run the turbos efficiently. Probably good for 8000 rpms @ 18-20 psi before u run dangerously close to the choke line.

It should also allow the 18'gs to make more power higher up in the revs than the PE system for example @ 10 psi I bet peak hp would come sooner in the rpm band with the PE turbos than the greddys by a little bit. What i mean is it looks lit the greddys in the higher boost application should continue to make more power higher up in the revs after the PE system has started to drop.

These are just theroys develpoed by looking at compressor charts it would be cool to see a dyno shoot off between a PE car and Greddy car at some different boost levels And see what happens.

t32gzz

iTrader: (1)

Skidazzle has the Garrett turbos, and I have the Greddy turbos. Keep in mind, both are running FMIC's, so this could prove to be the deciding factor, but at similar boost levels and under similar conditions on the exact same dyno, our graphs look very similar.

I prefer to use similar, because even a boost guage is not 100% accurate and can vary from one to another. Dyno's tell only part of this story. In a 1/4 mile run at the track, head to head, both at 7.5 psi, Michael's car definitely pulls ahead. Same track, same time, identical conditions. Even with identical 60' times and trap speeds, I think he would win by a nose or more.

If we put the exact same wheels and tires on it may tell a different story, I am on 20's, he is on 19's. Rest assured, we will go to the track again, maybe both on slicks or DR's and hopefully we can get a better comparison. I have driven his car and mine, and it just feels like the lag is less on the Garrett's. More efficient and quicker spool???

I hope this real world experience helps to compare the turbos. The Garrett's appear to be the most efficient at low boost levels, so if you factor PE into the equation, A PE turbo racing a Greddy turbo, both at low boost and identical conditions may have a slight edge. Rest assured, though, if I race a PE car, I will not be in low boost!