Dustin's UltraMarine FR-S (Engine Blew - LS3 Time)

[Jaden]

Originally Posted by DustinS

Started looking at the Twin Charged FRS builds. I wonder what it would take to install a Cosworth Supercharger and install a GTX3076 hmm. Obviously Respective FI items, Ecutek, Built Engine, Custom Intercooler to supercharger pipe (not too difficult). Now to find someone to tune the car...

What are your final power goals?

If you're doing a compound boost versus a take over, you need to be aware that the turbo will need to be capable of providing the airflow you need at the boost levels that the turbo alone will be running at.

So for instance if you're running the supercharger at 9 psi and want a final boost level of 24 psi, let's say, the turbo will max at about 10 psi, so if you want a top end power level of say 500hp, then you need a turbo that can push 50lbs/min at 10 psi. a GTX 3076r doesn't provide enough air at that level.

The reason a lot of people don't compound boost is that you'd have better top end power by using a turbo alone. With a smaller displacement engine like a 2.0l though the torque curve is so much better that it becomes well worth it if you get it working right and size the turbo appropriately.

Jaden

[DustinS]

Originally Posted by Jaden

What are your final power goals?

If you're doing a compound boost versus a take over, you need to be aware that the turbo will need to be capable of providing the airflow you need at the boost levels that the turbo alone will be running at.

So for instance if you're running the supercharger at 9 psi and want a final boost level of 24 psi, let's say, the turbo will max at about 10 psi, so if you want a top end power level of say 500hp, then you need a turbo that can push 50lbs/min at 10 psi. a GTX 3076r doesn't provide enough air at that level.

The reason a lot of people don't compound boost is that you'd have better top end power by using a turbo alone. With a smaller displacement engine like a 2.0l though the torque curve is so much better that it becomes well worth it if you get it working right and size the turbo appropriately.

Jaden

That is actually what I found out/realized as I looked more into it. Neither of the Australian built Twin-Charged cars ever posted numbers, but I was talking to someone this weekend about them and said they never made over 350whp on the twin charge set-up. The company I was talking to was running a GT35R (even larger now) on their set-up, but no numbers were mentioned either. So I have started looking at a Sprintex 335 and a GTX3576R or slightly larger. Now that I know where to look, I can size a turbo for the set-up.

I was wanting somewhere in the mid 400s on a low setting and close to 600 on a high setting, but it looks like I may not have THAT much control over boost, due to the way the system works. I want a highish power level, with a great torque curve that starts low in the RPM range.

It seems I may just have to live with the GTX3076R and possibly buy a new twin scroll manifold to get a better low end.

[Jaden]

Originally Posted by DustinS

That is actually what I found out/realized as I looked more into it. Neither of the Australian built Twin-Charged cars ever posted numbers, but I was talking to someone this weekend about them and said they never made over 350whp on the twin charge set-up. The company I was talking to was running a GT35R (even larger now) on their set-up, but no numbers were mentioned either. So I have started looking at a Sprintex 335 and a GTX3576R or slightly larger. Now that I know where to look, I can size a turbo for the set-up.

I was wanting somewhere in the mid 400s on a low setting and close to 600 on a high setting, but it looks like I may not have THAT much control over boost, due to the way the system works. I want a highish power level, with a great torque curve that starts low in the RPM range.

a positive displacement blower is definitely the way to go. Then you're getting max boost from the blower fairly soon in the RPM range.

The other good thing about a compound boost setup is that the S/C is providing more fuel and air so there are more exhaust gases sooner to spool up the turbo.

yeah with a low boost setting about 400, and a high boost setting around 600-650, that's what I'm looking at eventually doing as well.

I was looking at doing it at about 30 psi for high boost and 22 on low boost.

There are charts that show you what a compound boost setup would look like as far as how much boost you'd be getting from each power adder device.

at 12 psi on the turbo I don't know that even a 3576 would be enough, you'd probably need a 3582 to get where you want to be.

At first glance that would seem like overkill because if you're running 30 psi on a 3582 alone you'd be making about 700hp although you'd be pushing efficiency.

but in a compound boost setup you'll be closer to a 1.8 as opposed to a 3.0 so you max out power at about 600 still slightly pushing efficiency.

a 3576 wouldn't be able to push the air you need to hit 600 in a compound boost setup.

Jaden

p.s. one other benefit to note on a compound boost setup. If you were running a 3582 alone on a fa20, you wouldn't hit max boost until about 5500 rpm, where as in a compound boost setup, you'll likely hit the 12-15 psi by about 3500 rpm, plus you'll be closer to max boost much sooner because of the compounding of boost.

[DustinS]

Originally Posted by Jaden

There are charts that show you what a compound boost setup would look like as far as how much boost you'd be getting from each power adder device.

at 12 psi on the turbo I don't know that even a 3576 would be enough, you'd probably need a 3582 to get where you want to be.

At first glance that would seem like overkill because if you're running 30 psi on a 3582 alone you'd be making about 700hp although you'd be pushing efficiency.

but in a compound boost setup you'll be closer to a 1.8 as opposed to a 3.0 so you max out power at about 600 still slightly pushing efficiency.

a 3576 wouldn't be able to push the air you need to hit 600 in a compound boost setup.

Jaden

p.s. one other benefit to note on a compound boost setup. If you were running a 3582 alone on a fa20, you wouldn't hit max boost until about 5500 rpm, where as in a compound boost setup, you'll likely hit the 12-15 psi by about 3500 rpm, plus you'll be closer to max boost much sooner because of the compounding of boost.

Quick Search showed this. Going to do more research on a good calculator.

[DustinS]

Long Post, but seems I need to find the VE and BSFC of the FA20 with a 10:1 Compression (Going Element Tuning Big Valve Head)

Choosing the right turbos (math heavy)

This is where the fun begins. Well, for me at least as I love crunching numbers and toying around with figures. So you've decided you want to put the work in and run compound turbos, now you just need to figure out which ones you want.
I will assume that anyone who plans to use this already knows how to read a compressor map. If you don't, google it and learn on something more basic than this. You should have a reasonable understanding, otherwise this will get ugly fast.

Disclaimer here as well. I'm not sure if this is all right... use it at your own risk. I'm surprised how much air can flow given these numbers, but I've combed it over and over and it seems good. I have no references to cite, mostly a bunch of chicken scratch in a binder that I actually wrote this off of, but I think I read something on compounding maps by TDI Meister, who's both on here and TDI Club, so I'll say that credit for a lot of it goes to him

First step, how much power do you hope to make? Make sure there's overhead! I'll use my engine setup as an example the whole way through here.
If I make 180whp, I'll be stoked. I use a conversion factor of 1.15, which gives me 207hp at the crank. So, I'm going to figure out how much air it takes me to get 220hp crank. That would be 191 at the wheels which for now is more than enough power for me. All of this being at 4500rpm
I'm half addicted to a website called not2fast.com with a great calculator for figuring out power numbers if you know what info to give it. The most difficult figures to know are BSFC, AFR and VE. Here's a table of values that I use. I came upon these values from pulling my own sources and if anything seems off, I would gladly be corrected!

AFR
17.5:1

BSFC
<4000rpm - .34
4000-4500rpm - .37
>4500rpm - .40

VE
<3500rpm - 80%
3500-4000rpm – 75%
4000-4500rpm - 70%
>4500rpm – 65%


I realize stoich for diesel is around 14.5:1, but you'll be puking black smoke like mad and likely melting something at that point. I remember reading somewhere that TDI's begin to smoke at about 18.5:1 and IIRC, IDI's burn better due to the prechamber being more efficient than the TDI's design. With that, I expect a haze at 17.5:1
The BSFC I averaged out from a myriad of sources. Who knows if I'm right, but the numbers seem to make sense.
These VE numbers may seem low, but given the feel of these engines, either the BSFC or VE definitely tank after 4000rpm

After all of that, I was left with a manifold pressure of 35psi, pressure ratio of 3.52, mass flow of 23.6lb/min, 323CFM. Also, a BMEP of 332.6. Fairly high for my compression ratio (~20.5:1), but nothing stupid. Also, for reference, 220hp at 4500rpm is 255ftlbs of torque.. not bad for a 2400lb car!
http://www.not2fast.com/turbo/glossa...orDutyCycle=85
Now, the first turbo to size up is the LP turbo. It's drawing ambient air, so it's fairly simple to figure that one out. I had spent a while looking and kept going to smaller and smaller LP turbos, realizing that some monster down there isn't what I really want. I ended up going for a fairly simple option, a K24-2470. It's reasonably efficient up to a PR of 2.1, so I'll use that as it's PR. In a compound setup, the PR's multiply, so 3.52/2.1 leaves a PR of 1.68 for my HP turbo at max boost (35psi).
Not2fast.com has lots of compressor maps available, including one for a K24-2470. It's flow is actually rated in m^3/s, not lb/min, but using not2fast's simple conversion, (23.6lb/min)/162=.146m^3/s. Plotted on the compressor map puts it right where I want it to be at full boost. Now the easy one is done.

HP turbo becomes a little bit tougher because compressor maps are measured with ambient air as the input, but our HP turbo is taking in already compressed air. I'm still using the K14 that my engine came with so I only had to buy one turbo. Fortunately everything is nice and linear, so the equation to correct the mass flow isn't too tough. m2=m1*sqrt((T/Tmap)/(P/Pmap))
Temperature is the inlet temp divided by the temp used on the map, both converted to degrees Kelvin. Pressure is absolute inlet pressure divided by pressure used on the map, in whatever unit you want, as long as they're the same.
Temperature would be very difficult to calculate, so I just use the not2fast calculator from above, change the boost to a PR of 2.1 and use the temperature that spits out; 16.2Psi giving me an outlet temp of 126*C. Now, lets throw those numbers into our equation.

m2=m1*sqrt((T/Tmap)/(P/Pmap))
m2=23.6*sqrt(((126+273)/293)/(30.9/14.7)
m2=23.6*sqrt(1.362/2.102)
m2=23.6*sqrt(.6480)
m2=23.6*.805
m2=19.0

So, plotting 19.0lb/min, which converts back to .117m^3/s with a PR of 1.68 once again puts me very near the middle of the compressor map, even a bit low, just on the edge of the 76% island. Before I actually figured it all out, I was afraid my turbos would be too small, but assuming all this math is correct, I have tons of overhead!

One problem I've run into is that I don't know how to control a turbo by PR. I've been planning to run the K14's wastegate as the difference between my intermediate charge pipe and intake manifold. The problem I run into there is that for 35psi, that's a differential of 19psi. Meaning, for my K14's wastegate to open, it'll need to be making 19psi on top of what the K24 is making. That's not so bad once it's already getting compressed air, but that's a PR of 2.3 drawing from ambient which is off the compressor map. If anyone knows a way around this, please let me know, otherwise I'll have to do testing on it and figure something out. I only plan to run 30psi at the manifold for now at least, so it's not a huge problem, the K14 set at 15psi isn't too bad, but I'd like to control it better if I could.

Just out of curiosity, I extrapolated the numbers a bit to see what I could actually do. If I come across a good deal on a TDI long block and a cummins 4BT pump, I'll probably swap that in and run some big numbers. Using the link above, changing the boost up to 50psi, I get 278hp at the crank, 30.0lb/min flow and PR of 4.4. K24 would see PR of 2.3 @ .185m^3/s and K14 would see PR 1.91 @ .144m^3/s. Both of those are still near 75% eff! VERY close to the limit of the K24 though. To go higher than that, throwing the K24 on as the HP turbo and something capable of 35-40lb/min at PR of ~2.3 would put you in the 300+whp range at 60psi. Although, the TDI may flow better, so you might be able to do in the 300's on 50psi but bigger flow numbers. Garret GT30R maybe?

[Jaden]

Originally Posted by DustinS

Quick Search showed this. Going to do more research on a good calculator.

Yep and all boost control is done via the turbo, so you will always be producing the boost that the s/c is producing and then compounded with whatever the turbo is producing at a given time.

so it would probably be best to have a lower wastegate spring, say 5-6 psi and then an electronic boost controller to allow higher boost. That way you have more control over boost levels.

Jaden

[Jaden]

That long post about all the maths is referencing compounded turbos. What we're talking about here is much simpler because of a relatively static P/R that positive displacement S/Cs provide.

Jaden

[DustinS]

Originally Posted by Jaden

That long post about all the maths is referencing compounded turbos. What we're talking about here is much simpler because of a relatively static P/R that positive displacement S/Cs provide.

Jaden

Thank You for noticing that. Guess I didn't read into it enough.

Almost Wondering if the Cosworth Supercharger Might still work. It is a PD Charger with extremely efficient Air to Water Intercoolers. The Sprintex intercooler apparently isn't the Best.

From Cosworth

its an eaton TVS R900 and the cooling system uses a pair of water / air heat exchangers along with a 4 pass low temp radiator and a high flow electric pump to provide up to 40Kw of heat rejection -
this was sized to be sufficient to cope with the charger spinning at Vmax (20,000 rpm continous 24K inetermittantly) with charger exit temps of 120 degrees C but maintain 35 degrees IAT

[Jaden]

Originally Posted by DustinS

Thank You for noticing that. Guess I didn't read into it enough.

Almost Wondering if the Cosworth Supercharger Might still work. It is a PD Charger with extremely efficient Air to Water Intercoolers. The Sprintex intercooler apparently isn't the Best.

From Cosworth

With compound boost, the size of the s/c isn't too big of a concern, a tvs 900 will likely perform as well as a tvs1320.

The main thing to consider is the efficiency at the p/r you'll be running. You don't have to worry about air flow because that comes from the turbo.

Since you won't likely even need or want a high boost pulley and will only want to run around 9 or 10 psi out of the s/c, the tvs 900 should be plenty efficient at those levels.

Jaden

[DustinS]

Originally Posted by Jaden

With compound boost, the size of the s/c isn't too big of a concern, a tvs 900 will likely perform as well as a tvs1320.

The main thing to consider is the efficiency at the p/r you'll be running. You don't have to worry about air flow because that comes from the turbo.

Since you won't likely even need or want a high boost pulley and will only want to run around 9 or 10 psi out of the s/c, the tvs 900 should be plenty efficient at those levels.

Jaden

That is awesome to hear.

I am talking with the Street Attack Racing Guys in Hawaii who also have a twin charged FRS. They are looking for 1000whp out of their set-up though. I know they are running the new-ish Sprintex SPS 335. It is significantly more efficient than the regular 335. They were running a 35r, but have since upgraded to a larger turbo. Still waiting to see if they don't mind sharing their findings when running the 35R.

They told me the SPS335 would net me ~450whp and tiny bit of nitrous could be used to get me up over the 500whp hump. That just didn't seems as fun

http://www.facebook.com/superstreetm...4678384492907/

[Jaden]

Originally Posted by DustinS

That is awesome to hear.

I am talking with the Street Attack Racing Guys in Hawaii who also have a twin charged FRS. They are looking for 1000whp out of their set-up though. I know they are running the new-ish Sprintex SPS 335. It is significantly more efficient than the regular 335. They were running a 35r, but have since upgraded to a larger turbo. Still waiting to see if they don't mind sharing their findings when running the 35R.

They told me the SPS335 would net me ~450whp and tiny bit of nitrous could be used to get me up over the 500whp hump. That just didn't seems as fun

I was looking at a T76 turbo and an e-force myself.

The T76 at a 1.8 p/r keeps me in the 75-78% efficiency range at 60-70lbs/min of air flow.

besides it becomes much cheaper as I can get an ebay t76 and a replacement center cartridge for less than a $1000 total...absolute best bang for buck.

I'm building up the motor now and then I'll go from there, but I'll be looking at ~15K(12K and 16K after supprting mods really because I don't count my used engine and tranny buy that I spent $3200 on since I had to buy them anyways) total after built motor, e-force and turbo. ~20K when all supporting mods are said and done...

I'm just lucky I have an extra tranny in my shop lol once I have that much power. I'll also be doing things piece meal. First thing is....actually that's under wraps for now. First thing is getting my original motor built up.

Jaden

Yeah, a 650whp 2800lb car for a total of a little over 40K...pretty tough to beat...lol

[spitfire481]

i don't ever see 1000whp coming out of an fa20. im at 666whp at 28psi on a 6766 currently. maxed the di and pi (90% duty) with 1650's. switched to id2000's with 60psi base pressure and will be continuing thursday to 35-40psi. Id need 12 injectors to get to 1000whp on ethanol lol.

[DustinS]

Originally Posted by spitfire481

i don't ever see 1000whp coming out of an fa20. im at 666whp at 28psi on a 6766 currently. maxed the di and pi (90% duty) with 1650's. switched to id2000's with 60psi base pressure and will be continuing thursday to 35-40psi. Id need 12 injectors to get to 1000whp on ethanol lol.

I don't ever expect to see it out of their set-up either. Especially not with the supercharger in the way. I suspect they have a lot to learn in the Twin World, They seem more attuned to V8 stuff, and some of the comments have me concerned at even that.

[Jaden]

Originally Posted by spitfire481

i don't ever see 1000whp coming out of an fa20. im at 666whp at 28psi on a 6766 currently. maxed the di and pi (90% duty) with 1650's. switched to id2000's with 60psi base pressure and will be continuing thursday to 35-40psi. Id need 12 injectors to get to 1000whp on ethanol lol.

Even 666 is pretty insane when you think about it..

that's over 300hp per litre...lol...

Jaden