Compound turbo rb25 in s13

[FutureFab]

Ive been running a modified stock log with ebay t70 for two years or so and I had two broken exhaust studs that were bothering me. After taking it apart and fixing them I just couldnt put the stock log back on. So I figured it was time to build a new manifold. I didnt want just another top mount either. It was time to go compound and loose the lag.

The diesel boys have been doing this for years. For those unaware how it works, basically all the exhaust runners go into the little turbo first, it spools and the down pipe goes up to the inlet of the larger turbo. A waste gate before the little turbo opens at X psi and bypasses the little turbine and is routed back into the big turbo before the turbine wheel. A second gate controls the boost of the big turbo and vents to atmosphere.

On the Compressor side, the lil turbos inlet is drawing thru the big turbo until the big turbo spools and pushes thru the compressor of the little one.

So the little turbo spools quick then runs out of top end, as its doing so, the big turbo finally has enough energy and starts making psi and takes over up top. Its a seamless transition and it works great!

I did this on a budget and salvaged parts that were either on my car or on my spare sr sitting in the back. Some things like head flange and stainless elbows I had to buy.

Hardware.

Bb s15 spec r t28
Journal bearing ebay t70 t3
Tial 44 mm to bypass t28 and feed t3
Tial 38 mvs to control boost of big turbo



Empty exhaust side.
http://img263.imageshack.us/img263/1228/compoundturbopics003.jpg
The hardware.
http://img88.imageshack.us/img88/5082/compoundturbopics001.jpg

http://img232.imageshack.us/img232/3256/compoundturbopics016.jpg

http://img197.imageshack.us/img197/2056/compoundturbopics024.jpg

http://img502.imageshack.us/img502/3807/compoundturbopics026.jpg

http://img208.imageshack.us/img208/5489/compoundturbopics033.jpg

I was previously making 1 bar at 4500 with my log/t70 setup. Now I am making 1 bar at 3000. This is still on pump gas. There is lots more to go, now I need to switch back to draw thru maf (maxing out with blow thru) and upgrade injectors beyond the 550s in there now. It actually has more traction in a strait line since there isnt a "hit" of power at 4500, it just spools asap and keeps pulling. If I turn the wheel just a tad, it just breaks traction and goes to limiter unless i feather it. Dont even need to clutch kick, just mash that skinny pedal and chong.

[Flicktitty]

VERY COOL!

i've seen a few people do this on the 2JZ with great success.
IMO this is the way to go if you have fab skills, great work!

[fearlessKouki]

unique setup for sure!

[ch1873857]

this is GOOD SHIT. Impressive stuff! would love to see some videos of that..

[Jtuned_andy]

Wow, looks like a technical nightmare but if it works that is downright awesome! haha

[mikey976]

i think everyone will agree when i say give us some videos

[turbociv910]

very cool, looks like a pita to install!

[FutureFab]

Its not too bad to install, just has to be in order. Making it was the pita.

Going to the track after dinner, will take some video.

[azn2nr]

subscribed for results.

ive always wanted to do a compound turbo settup but was always troubled by the complications that come with it.

one problem that troubled me in my research was the recompression that occurs when the big turbo comes on. because the small turbo doesnt care that the air is already compressed it continues to compress it at whatever rate it can, and due to natural backpresure its impossible to slow shaft speed of the small turbo to the point that it wouldnt recompress the air. sort of like the way stacking in line fuel pumps works.

i have no direct experience with it but draw through just seems like a bad idea because of recompression.

[mxracerjason]

What ECU are you using. I curently have the stock RB25 ecu in mine and the two things that need to change are the rev limiter the stopes at 6100, would like it moved to 7200ish and the speed limiter needs to go. It cuts out at 123mph. I will be upgradeing to a Vi-Pec that will fix all of that, and after it gets tuned it should make about 400+ rear wheel.

[idahotuner]

awesome, wish you had pics ofit on the motor out of the car

[FutureFab]

Well my phone battery was dead so i only got one video. Need to host it then post. Will have to do until next week.

Ecu is power fc.

Imageshack wont let me log in from phone or laptop. Have to play that game tomorrow.

[FutureFab]

Finally got the video

2011-12-06_21-03-25_509.mp4 - YouTube (http://youtu.be/HdGEhEuiEmI)

[rb20240sx]

sweet setup always have thought about doing this

[twinspool]

that is amazing, just the other day I was thinking about this set up too hahah

[PoorMans180SX]

Dang, that looks like a blast. I would really like to do a compound sometime in the future.

If you wanted to even add more complexity, you could add a quick spool valve to the T70. Would be interesting to see how it worked.

[AS240]

that is awesome man! do you still have the old stock manifold you were using? did you modify it in any way?

[FutureFab]

No more room or else Id try and put a QS valve on there. I still need to play around with it if im going to make any more power. Ill probably go dyno to get a baseline, then up the injectors and lean on the big one a bit harder. After that is Neo cams and extra capacity oil pan.

The stock mani was modified in two ways, 1st I put a hole in the collector for tial 44, 2nd was a spacer was welded to the t3 flange of mani to space turbo out to get compressor clearance. I already sold it just to make sure I finished the project and didnt go back to stock.
http://img.photobucket.com/albums/v143/4got10/s13rb007.jpg

[PoorMans180SX]

Are you routing the copper gate to atmosphere? Doesn't that kind of waste the exhaust energy that could be going to the T70? Obviously you don't have much room to work with but...

I guess it would definitely regulate boost better that way.

[FutureFab]

Good eye, that was a experiment. It was using the internal gate routed back in to the big turbo. I could have left it as there was no noticable gain.

[Fred Allen Burge]

I can not believe you fit all that in there! Nice work, I'm glad it actually worked for you.

[AS240]

The stock mani was modified in two ways, 1st I put a hole in the collector for tial 44, 2nd was a spacer was welded to the t3 flange of mani to space turbo out to get compressor clearance. I already sold it just to make sure I finished the project and didnt go back to stock.


did you use a 10mm plate to space the turbo, and did you have any clearance issues with the steering shaft? i have been looking at doing this but there isnt a whole lot of info out there.

[PoorMans180SX]

I PM'd you some questions good sir.

[FutureFab]

For stock manifold you can use a 10mm spacer on turbos with E compressor housings, like a 57 trim. My turbo had a S compressor cover, so i used two t3 flanges, one cut diagonally from one face to the other making wedges. I turned them the same way to"make a bend" away from the manifold. The second flange was then placed on for the turbo to bolt to. Down pipe clearance was close but some bends made it in there none the less.

[AS240]

would you happen to have any old pics of fabing all that? my brother just got a miller dynasty 200 so i want to start fabing up my own stuff. thanks again

[FutureFab]

Looks like so..

http://img.photobucket.com/albums/v143/4got10/Rbs13Feb001.jpg

http://img.photobucket.com/albums/v143/4got10/Rbs13Feb010.jpg

http://img.photobucket.com/albums/v143/4got10/Rbs13Feb014.jpg

http://img.photobucket.com/albums/v143/4got10/Rbs13Feb002.jpg

http://img.photobucket.com/albums/v143/4got10/Rbs13Feb017.jpg

[AS240]

you have true talent man. im going to hopefully modify my manifold this weekend once i finish all my finals. i want to fit a pte5857 with the S housing down there. any advice that you learned along the way is greatly appreciated since this will be my first time fabricating anything. you can pm me if you do so it doesnt clog up your thread. thanks man!

[FutureFab]

My old megan camber arms were totally maxxed out in length and I still had negative camber, so I cut them up and made some new longer ones. They are even lighter than the old ones too. I had Eleven's Paint and Fiber blast these mofo's with a custom blend of red and pearl.

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/8B31F20B-orig.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/605BACEE-orig.jpg


And some more compound pics..
http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/72FC27FF-orig.jpg

Down pipe vs brakes
http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/2DB4431D-orig.jpg

4" down pipe clearance.
http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/compoundturbopics042.jpg

[smgopedguy]

Cool Car bro!

[FutureFab]

A couple more videos from this week...

http://www.youtube.com/watch?v=CoIf0hRRXj4

http://www.youtube.com/watch?v=G_6HyCACPIc&feature=g-upl&context=G23c24d1AUAAAAAAABAA

a little blurry on this one
http://www.youtube.com/watch?v=r-VJdIYTqyQ

[ashtonroche]

Sick setup man, Sounds like it does good.

Yeah id definitely see about routing the copper gate back to the t70, basicly to use as a backpressure relief as im sure that much power being pushed through the t2 you will start to see high back pressures and im sure that gate is dumping some of the pressure you could use to spool the t70 up.

Very nice setup overall man and yeah cant believe you fit all that in there. Good job.

[furr]

Nice setup, and enjoyed the videos

[AS240]

[QUOTE=FutureFab;4418639]A couple more videos from this week...


2011-12-20_21-11-47_519.mp4 - YouTube (http://www.youtube.com/watch?v=G_6HyCACPIc&feature=g-upl&context=G23c24d1AUAAAAAAABAA)


WOT transitions and then kissing the rumblestrip....nicely done ahaha!

[Walperstyle]

do you have a dynograph for this setup?

PS. I would highly advice having some kind of heat shield between the turbo and BMC.
This is not safe
http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/2DB4431D-orig.jpg

[ralphandthequeen]

wicked tits.

[FutureFab]

Damnit Walper, why didnt you say something sooner? I melted the master 4 hours before your post. Lol. I knew it would happen esventually anyway. So now I just ordered pathfinder master to get the lines on the other side. Thatll free up some room for a proper heat shield.


I have a dyno graph that ill have to post later. It makes the same peak power but has about 80 ft lbs more down low.

[FutureFab]

So here it is, some apples to apples comparison on the same dyno over at Lowcash Racing in Phx.

Both pulls were using pump gas 91 octane.

The skinny lines are Old Tq and Hp with the stock log, and ebay t70.

The thick lines are the New Tq and Hp with manifold, s15, and t70.

The maf was moved to Draw thru and ecu retuned around this.

Everything else stayed the same on the car, only changes were in tuning and boost controller settings. The new setup needed much more fuel and some timing pulled out. The other variable, the electronic boost controller. In the old setup it was on the one and only 44mm (10psi spring) with some added duty cycle across the board to get to 14 psi. Even with the controller it took forever and a day to spool that turbo. Once it hit it felt great, and if you can keep it in the power band, its all gravy. On the new setup, the 44mm (still 10psi) was in charge of regulating the little turbo, and the second wastegate 38mvs (7psi) was charged with regulating the big turbo. I used the controller and added duty to get the big turbo back up to 14psi. I plan to change out the 38mvs spring to 14psi to free up the controller and get it over to the 44mm to get more spool out of the little turbo. Since its just spring pressure, its slowly opening as boost builds vs having the controller hold it shut til the desired pressure.

Blah blah blah...Dyno sheet time.

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/1548306F-orig.jpg

Its clear there is more torque spread throughout the rpm band, with the biggest jump being about 80 ft lbs.

More hp is available everywhere except the last 500 rpm, as Duty was pulled back just a tad to promote shift.



Since the dyno, the spring on the little turbo went from 10psi to 14 psi. Can definatally feel more low end umph, still no boost controller on it tho. That lil black mark on the sheet is my guess as to Tq gained from the spring change. Who knows, could be wrong.

Added some duty to the big turbo and put it on 17 psi. Again can feel a differance as the just keeps pulling up top. Compressor is a little louder too.

Had to close the gap on plugs, blowing spark out. went down to .022, feels so smooth now.

Melted plastic Bmc, teeheeheh.

[PoorMans180SX]

Thanks so much for posting graphs and keeping the information coming, this is cool stuff.

[Imarvin240]

thats a sick setup, great job on all the work that had to go into that.

[FutureFab]

Got the pathfinder bmc with the lines on the other side, made tons of room between down pipe for heat shield. Also made some new Dot brake lines. They fit nice and are hid away, cleaning up the fire wall a tad.

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/AABB93EA-orig.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/0866FB1F-orig.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/7B984AE8-orig.jpg

Pics of the recirculated gate.
http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/4A6FEF78-orig.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/4376861B-orig.jpg

[s14unimog]

right the f**k on buddy; that is some killer work. I admire your get it done attitude. Car sounds beast!

[FutureFab]

Thanks man, there is just always something else to do or try. While the bmc was off I also took off the rear subframe and did solid mounts. Slammed the frame to the chassis and cut the chassis for more arm clearance.

I was able to make a stainless heat shield today. Going to add a piece to fully cover the down pipe and get heat away from coils.

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/4B52BC58-orig.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/E31FDE57-orig.jpg

[Big Zee]

that is a nice heat shield. great job on the manifold. I'm going to suggest this idea to my buddy who is running a similar sized turbo, this looks like it would take out the lag problem all together.

if the rep system was still in place, you could bank on another +1

[FutureFab]

Hit the Drift and Drag tonight. Tech line was super long, took forever. Wanted to drag race just to see what shes doing, but there were soo many draggers there, wasnt worth the hour wait in line.

So I drifted. Car felt great, super responsive and didnt break anything. Brakes are holding strong, heat shield is doing its job. Now its time for new rear tires.

January drift and drag - YouTube (http://www.youtube.com/watch?v=nQi64NMwIQQ&context=C31a747eADOEgsToPDskLwdZP8NJVCoVHgcXISDlfH )

[Kingtal0n]

As you continue to inspire the community... hold nothing back

[FutureFab]

A friend found this video on youtube, its from the same night as my last video post. Im in it a few times, gives you an outside perspective of whats going on. Im the grey car with one headlight making the shmoke.

FIR Drift 1/27/12 - YouTube (http://www.youtube.com/watch?v=4K9071UB3WU)

[FutureFab]

Another little video of my car at the same recent drift n drag.

Drift Night at FireBird - YouTube (http://www.youtube.com/watch?v=OwcCx_VtaI0)

[AS240]

anything new with the setup?

[FutureFab]

Alot has happened since last post. Ill try and touch all the major bases along the storyline.

Hurt the det transmission at the track one night a week before Xdc round 1/2 season opener in Phoenix. OUch. Scurried quick to find a trans local. Found one and picked it up monday night. I still had stock sheet metal front end that was more or less swiss cheese, so this was the perfect time to add some tubes.

Now you can see the setup on the motor.

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/05100F54-orig.jpg

It was tuesday and round 1 was on friday.I stayed up each night til 3 or 4 in the morning after I got off work. I had to build the tube front, remount the radiator and Ic, put the swap back in, adjust the Ic piping, add front tow hook, battery cut off, hood pins, clean up my wiring, and adjust alignment and some other loose ends. I also moved the rack forward and built a oil pan for more ground clearance.

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/CD0BE8F2-orig_zpsae90d567.jpg

Then I needed saftey gear. I had to get a seat, new harness, fire suit, fire shoes and socks, helmet, and gloves. Luckily we sponsored Andy Lee of Bondurant School of Driving with a road race cage for his World Challenge Camaro (he later won rookie of the year and took 2nd overall in points this year) and he hooked it up fat with most of the gear I needed. Thank you Andy!

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/5D8DEAF5-orig_zps59a29c9a.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/900A691B-orig_zps4223e344.jpg

So it was thursday night and it was becoming clear that I wouldnt make fridays race. What a bummer. I was in a slump. Friday morning I get a call from Vitaly Sopkin and he asked if he could borrow my catch can to get his car to the race. Since I wasnt going, I let him have it to get him on the track. He also said one of the guys at the track needed his cage modified to pass tech. He came from out of state and really needed it done asap. So I told him to come down to the shop. I went to the metal store and picked up some Dom to make his diagonal in his hoop. I made the bar and got him passable for the track. After I got him out the door i started chipping away at my car again. Later that day it was close, I still needed fire undies and driving shoes and a fire extinguisher. It was now or never. At 3pm on friday I went and dropped 360 bucks on Alpinestars shoes (the only size that fit me in the store) fire undies and a fire extinguisher.

I went back and kept working on my car. At around 10pm I registered for Saturdays race online. I dont know what took so long but it did. I was up allllllllllllll night no sleep finishing the car. I remember mounting the seat and just being delusional from lack of sleep. I made the mount and welded it and inch off. cut it off and made it fit. At 830 am the car was done.

I went home quick, showered and went right back out the door. I drove the car to the track with spare tires in the car along with all my tools and jack. I got my wrist band and proceded to tech. Made it just in time and passed. Then drivers meeting, a break, then practice. This was my first drift competition and there were some pretty serious cars there from all over. My first practice session sucked as I was trying to get used to the course and what not.

After first practice was an hour break, I went and ate some burger king, first thing I ate since the previous night. Still no sleep, but a second wind was coming.

Second practice started and I was feeling it. It was a strait line to the first blind right and I was hitting it in 4th. The car felt really good for an eyeball alignment and just being thrown togeather. I saw Garret N. in the line and we decided to tandem. He led I followed close in 4th. He got a lil squirrly and I was close and dedicated to my line. We met.

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/28A92B76-orig.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/66943DEC-orig.jpg

http://i1083.photobucket.com/albums/j398/2weldit/Snapbucket/534E2289-orig_zpsb3d04c3f.jpg

Fuuuuuuuuuuuuuuuuuuuuk.

I just made that.

I went back to the pits to check it out.

Evil Dan and I ripped off the hood and headlight and all the mechanicals were still fine, even the ic pipe, it just had a dent. My tube front wisker was bent into the tire tho. Big buddy Gerald came to the rescue and HeManed that Ish back out of the tire. Back into the car and back to the track. Well I got there just as practice was ending. I asked for just one more run but they said no.

One more hour break before qualifying runs. Dan noticed my right rear tire was burning a tad more on the inside, so we cambered it out a tad real quick.

2 qualifying runs to get into the main. I qualified 13th. Woohoo! Im in! And they only took top 16.

Pics I found on net of my mangled car. Wont let me save and upload tho.
http://www.flickr.com/photos/timeconsumer/7101416357/
http://s746.beta.photobucket.com/user/gagegriz/media/XDC%20Round%201%20and%202/IMG_4709.jpg.html?sort=3&o=63

Practice before the final Dan was spotting me and telling me I needed to snap harder and sooner. I did and he said it looked great, just do that. Third practice was over and as Im going back to pits my car is dying. WTF. I didnt have a gas guage (or any guage cluster for that matter) so I figured its out of gas. 20 min til top 16, Gerald runs to get me gas. He makes it back as they are calling my name on the loud speaker. Eeeeeeek! Dan runs over and tells them im out of gas, just need a min. We get some in there and head to the line. Dan keeps filling it up with multiple jugs.

Couple guys go then its my turn. Im following first pass. Dude misses a shift and duffs me up. I had to slow down not to rear end him He grabs a gear and pulls out a tad, I get it into 4th but im off my line. I end up going off track at the 3rd turn.

Next run im leading. I stand on in hard and hit all the apexes Fasssst and wide. It was awesome. But I was now going too fast into the reducing speed area and straighten for a second. Dang, I blew it. I got booted first round.

It was super fun and Id do it all over again in a heart beat. More to come...

[s14unimog]

Killer work ethic, sucks about the damage man. Props on the setup; keep at it.

[FutureFab]

Thanks man. I had some front end parts laying around and got another one on there.

[hypercrush]

john you are my hero. lets make your car pretty someday.



...and make babies


#creeper

[FutureFab]

Thanks Dylan, with our powers combined we can surely make a beautiful beast.