Building a sequential turbo system
#121
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interesting, I love the concept of dumps activated on boost. I have been kicking around the idea of having my dumps activated via a hobbs switch and relay. The only real problem is the motors take so long to open it may not be worth it unless your were wide open for awhile. Good find
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#123
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Well I got the induction side done today. It was a little bit of a bitch bringing the turbos together with that little room so it took a little, ummm, finesse. Anyway, all in all, it came out clean I think. This pics aren't that good because I only snapped a few pics as the build progressed and most of those suck lol. I'll post some of the better ones below..
Anyway, I'm only running it at 5psi right now and she's getting a little knock in the upper RPMs hopefully due to the fact that I forgot to change out the stock plugs on the drivers side. In any case, I've got some tuning to do on it. In the lower RPMs, it feels good for 5psi. No guess as to the power levels. Tomorrow, I am going to work on tuning and test some spool times with the valving set manually in different positions. I'm curious to see how the car will respond.
So the pics:
This shot shows the first piece of the primary turbo cold pipe. I had to make this in two pieces due to the routing. I had originally planned to drop it down the hole under the battery but didn't want it running that close to the exhaust. I ended up routing it around the battery tray through the fender and down under the head light. Yes it was a pita but despite the difficulty building and installing it, I really like the way it turned out. I apologize up front for not getting any better pics of this installed.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_primary.jpg)
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_primary-1.jpg)
Here is a the rest of the "warm side" (pre-IC) y-pipe. The pipe above connects to the straighter of the two pipes. The 180* connects to the secondary turbo.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_ypipe.jpg)
The merge I made..
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_merge.jpg)
Finally, here is the cold side pipe heading into the throttle body.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_throttlebody_elbow.jpg)
And an engine bay shot. Please forgive the crap everywhere. I had just rough fit the PCV, wastegate, and boost gauge in to start the car.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/enginebay.jpg)
The rest of the pics it's hard to tell what is going on (more than these lol). Anyway, I've got a few more odds and ends to button up before calling the fabrication phase of this build done. And of course, done just means the car is boosted. The real 'fun' begins here.
Anyway, I'm only running it at 5psi right now and she's getting a little knock in the upper RPMs hopefully due to the fact that I forgot to change out the stock plugs on the drivers side. In any case, I've got some tuning to do on it. In the lower RPMs, it feels good for 5psi. No guess as to the power levels. Tomorrow, I am going to work on tuning and test some spool times with the valving set manually in different positions. I'm curious to see how the car will respond.
So the pics:
This shot shows the first piece of the primary turbo cold pipe. I had to make this in two pieces due to the routing. I had originally planned to drop it down the hole under the battery but didn't want it running that close to the exhaust. I ended up routing it around the battery tray through the fender and down under the head light. Yes it was a pita but despite the difficulty building and installing it, I really like the way it turned out. I apologize up front for not getting any better pics of this installed.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_primary.jpg)
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_primary-1.jpg)
Here is a the rest of the "warm side" (pre-IC) y-pipe. The pipe above connects to the straighter of the two pipes. The 180* connects to the secondary turbo.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_ypipe.jpg)
The merge I made..
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_merge.jpg)
Finally, here is the cold side pipe heading into the throttle body.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/coldside_throttlebody_elbow.jpg)
And an engine bay shot. Please forgive the crap everywhere. I had just rough fit the PCV, wastegate, and boost gauge in to start the car.
![](http://i140.photobucket.com/albums/r13/Speed-ls1/enginebay.jpg)
The rest of the pics it's hard to tell what is going on (more than these lol). Anyway, I've got a few more odds and ends to button up before calling the fabrication phase of this build done. And of course, done just means the car is boosted. The real 'fun' begins here.
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#127
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I'm going to try to get on the dyno on Sat with it to get a good base street tune in it. I've been fiddling around the last couple of days working out bugs. I think the oiling issue is solved with the installation of the .029 jets. Might step down a little more if it continues to be a problem. That little 3gpm pump just couldn't hold the oil flow with two wide open 1/4in feed lines! The oil cooler really seems to be helping the turbo temps.
Another interesting issue was the wastegate wouldn't open. It was really fun to be expecting 5psi and watching jump to 10 when you start pulling your foot at 6. But for those .10 seconds or less, I was free. Actually, it made the ***-o-meter very happy minus the pucker factor. I found out the valve stem channel had a tiny ridge at the top that was stopping the valve from opening. Cheap chinese knock off
. So I worked the top edge down a couple thousandths with a 1/2in bit and reamed the edge with a file and it works like a champ now. I also got a gate with a 9lb spring(s) and ordered a 5lb spring separately. It didn't come with any instructions (cheap chinese knock off) so I installed the "5"lb spring by itself which allowed the exhaust pressure to blow the valve open at about 2psi. But it was a fun 2 psi! My original gut feeling was to just replace the inner of two springs with the new 5lb piece but better safe than sorry. So I replaced the original outer spring and low and behold, it works like a champ. Lessons learned? I bought this gate more as a matter of curiosity than anything. I figured I would try it and see how I like it. The 110 dollar knock off of a 900 dollar wastegate works great if you are willing to fix the poor machine work and muddle through the details with no instructions. The materials and castings seem fine and the anodizing has actually turned out to be quite resilient (yes I dropped it). I'm also happy with the over all design in that I can pull the wastegate out of the car, pop the top, change springs, and put it all back together and in the car in less than 10 minutes with no gasket change.
Anyway, all that put back together, it's running at 5psi and feels healthy for the boost level. I'll probably leave the 5psi spring in place and bring my DIY MBC to the dyno and work out an 8psi tune for pump gas and perhaps a little more for the race gas. Also ordered an FJO wideband controller from Greenlight to play with until my system controller is reading the wideband. I'll keep everyone updated to the results of the straight twin turbo operation.
Another interesting issue was the wastegate wouldn't open. It was really fun to be expecting 5psi and watching jump to 10 when you start pulling your foot at 6. But for those .10 seconds or less, I was free. Actually, it made the ***-o-meter very happy minus the pucker factor. I found out the valve stem channel had a tiny ridge at the top that was stopping the valve from opening. Cheap chinese knock off
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
Anyway, all that put back together, it's running at 5psi and feels healthy for the boost level. I'll probably leave the 5psi spring in place and bring my DIY MBC to the dyno and work out an 8psi tune for pump gas and perhaps a little more for the race gas. Also ordered an FJO wideband controller from Greenlight to play with until my system controller is reading the wideband. I'll keep everyone updated to the results of the straight twin turbo operation.
#128
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Originally Posted by 30thTA0525
looks awsome dude.. gonna have too take a little road trip in the ole TA and come down too check it out and see you guys
#130
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its all coming together for you now speed! ![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
what engine is this on??? (cant believe i haven't asked this beofre! lol)
did you get chance to test the operation od the sequential turbos?? how does the spool feel on the but dyno??
thanks Chris.
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what engine is this on??? (cant believe i haven't asked this beofre! lol)
did you get chance to test the operation od the sequential turbos?? how does the spool feel on the but dyno??
thanks Chris.
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Glad you figured the oiling out... Are your turbos ball bearing or journal? Just curious due to restrictor size.. also where did you place the restrictor? Thanks a lot man, coming together well!
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#132
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Chris - It's on a stock LS1. Speaking of which, if anyone wants a good running bone stock LS1 short block, lmk! Drive it before you buy it if you can get to Oklahoma! Daddy just scored a forged bottom end courtesy of Tiago's unending need to build something better. Knowing him, it's something evil! ![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
Superman - I'm running oil bearing turbos. For the price, I think ball bearing turbos are a waste of money. I've run jets as small as .016 before and have done so for 4 years and tens of thousands of miles on the same turbo system. I use a -3 nitrous flare to 1/8th npt fitting. There is a picture of it somewhere on page 3 iirc. I run these fittings at the oil feed inlet on the turbocharger. In this car, I am running two (one per turbo). I'm still getting a little smoke at WOT but I think I am going to build an accumulator to give it a little buffer and just keep experimenting.
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Superman - I'm running oil bearing turbos. For the price, I think ball bearing turbos are a waste of money. I've run jets as small as .016 before and have done so for 4 years and tens of thousands of miles on the same turbo system. I use a -3 nitrous flare to 1/8th npt fitting. There is a picture of it somewhere on page 3 iirc. I run these fittings at the oil feed inlet on the turbocharger. In this car, I am running two (one per turbo). I'm still getting a little smoke at WOT but I think I am going to build an accumulator to give it a little buffer and just keep experimenting.
#133
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so your all the way down to .016 at each turbo and they're journal? Makes me wonder if i jet down more if that will solve my issue as well? Sorry to jack the thread, i'm just trying to find any and all other solutions before resorting to shipping my turbo out to be checked. I run a .052 at the base of the feed (start of line above oil filter), if you have any suggestions, please PM me. Thanks man and glad your build is shaping up, look awesome and you did some great work!
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Nono, I'm using a pair of .029 jets right now. In the past I have used a .016 jet on a single turbo app I built about 5 years ago. I ran it for a couple of years and sold it to a friend who, as of last year, was still driving it. I've since moved and have no idea if he's driving it any more. It was also placed right at the oil inlet.
Since you are exhibiting the same symptoms I was, I'm guessing your turbo is fine but it might not be a bad idea to replace the seals. It's very easy to rebuild Garrett turbos which a large majority of the aftermarket performance turbos are based on. Don't worry about the hijack. It's pertinent to an issue I had here and it might help some poor bastard searching for an answer in the future.
Since you are exhibiting the same symptoms I was, I'm guessing your turbo is fine but it might not be a bad idea to replace the seals. It's very easy to rebuild Garrett turbos which a large majority of the aftermarket performance turbos are based on. Don't worry about the hijack. It's pertinent to an issue I had here and it might help some poor bastard searching for an answer in the future.
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#135
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Is it possible for me to order a rebuild kit and check it out and do it myself or do you need special **** hence usually having to send it out? Have any insight as to where i should go down to for a restrictor having it at the base of the feed. I think both of my turbos are the same as your smaller one i believe.. maybe not? Thanks man, i really appreciate the help and such! Might be best to take this to PMs or i will take over your thread, haha.
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#136
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your PM box is full....
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#138
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Just a few updates. I've been working the bugs out of the turbo system for the last couple of weeks. Honestly, I've been slacking a bit since I needed a little bit of a break lol. So far, I've put in a very very very very conservative base tune on it and set the boost at 6 - 6.5psi. I'm pleased with the numbers so far in that I can put down full boost below 2500 through the full exhaust and anything over 3k it spools within 200 rpm of nailing it. I think I can improve that a bit with a boost controller to keep the pressure ramp off the gate until I want it there. I haven't done any testing through an open exhaust but that will contribute some gain in spool time as well. This is all in twin turbo mode. Theoretically, all the spool time numbers should half themselves. A spool time of 50 - 100 rpm under race conditions would feel just off of instantaneous.
I dropped the oil jets down to .016 and still get a good amount of oil flowing out of the turbos at idle. I'm still wondering a little because there was no way in hell I was flowing 3 gallons of oil a minute with the .029 jets yet it would smoke some at full throttle. Oh well, I'll keep cranking away at it. When I go through the engine, I think I am going to just tap the pan and gravity drain them if I can find a routing that will allow it. The lower turbo is higher than the oil pan but not by much.
I did get my new FJO wideband in this weekend so I might get that installed this week. I'll tune it in on the appropriately located and legalized piece of asphalt for a good real world tune and take it to the dyno to work out any remaining little issues. I also owned my 3rd gear syncro and the clutch isn't liking what I optimistically hope is torque nearing 500ft/lbs. I've got a twin disc waiting it's turn to go in and while the trans is out, I'm going to go through it with new CF syncro parts, brass pads, billet keys, steel shift fork, etc. By the time this build is done, the entire powertrain will be brand new lol. The only upgrade part I didn't get for the trans is the viper output shaft which I don't think I'll need since I'm not building it for drag racing and the stock shaft should do fine for the few times I do go out there.
More updates to come!
I dropped the oil jets down to .016 and still get a good amount of oil flowing out of the turbos at idle. I'm still wondering a little because there was no way in hell I was flowing 3 gallons of oil a minute with the .029 jets yet it would smoke some at full throttle. Oh well, I'll keep cranking away at it. When I go through the engine, I think I am going to just tap the pan and gravity drain them if I can find a routing that will allow it. The lower turbo is higher than the oil pan but not by much.
I did get my new FJO wideband in this weekend so I might get that installed this week. I'll tune it in on the appropriately located and legalized piece of asphalt for a good real world tune and take it to the dyno to work out any remaining little issues. I also owned my 3rd gear syncro and the clutch isn't liking what I optimistically hope is torque nearing 500ft/lbs. I've got a twin disc waiting it's turn to go in and while the trans is out, I'm going to go through it with new CF syncro parts, brass pads, billet keys, steel shift fork, etc. By the time this build is done, the entire powertrain will be brand new lol. The only upgrade part I didn't get for the trans is the viper output shaft which I don't think I'll need since I'm not building it for drag racing and the stock shaft should do fine for the few times I do go out there.
More updates to come!
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Speed has allowed me to go for a ride in this car and may I say holy **** this car runs good and the craftsmanship is awesome. It will easily hand my car its *** when its all said and done. Now I will have to get a 9lb pully and hope I can at least keep from embarrassing myself
. Hey buddy keep up the good work and let me know on that clutch when your ready to install!
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