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I've been trying not to post about this and get as much data as possible. I've got a 90% drag car that makes way to much power for my street tires to hold, so only real data testing has been the two times to the track this year
Setup, LS3, 1-3/4 header into 2-1/4 hot pipes, 1.32 s480 into a 4 inch DP that necks to 3-1/2 for about the last 18 inches before the fender exit, two 44mm wyntomm gates with 10psi and tried 4psi springs
Data, last season was running standard cover with billet wheel, 4l80e trans with 3.25 rear gear on a Hoosier 28x10.50 slick. I was also running a frozen boost 9x10x4 water/air intercooler intake temps were 80 to 90* in the 1/4 mile. At 18 psi of boost car went 167mph in the 1/4 and was doing 132 in the 1/8, but at the local 1/8 mile which is like a nonprep setup I was seeing 127/128 mph. All of this at 70ish % duty cycle on the boost valve with a 10psi spring. The 4lb spring would only make about 12psi all in.
That's all great and car ran awesome. Now comes winter and upgrade season
I installed a race cover on my billet s480, went from an 80e to a 1.80 Glide, and got rid of the intercooler in favor of a fuel injector preturbo spraying fuel system fuel of E85
Took car out to the local noprep type 1/8th mile. (Well it is prepped, it's just an old asphalt airport that is not the greatest conditions). My gates had the last seasons 10psi springs in, knowing things would be different, I pulled dc out to learn it was over boosting. Long day short, in 8 passes I learned I had zero boost control, and that running with boost off the car would creep from 10psi to over 16psi
Car ran 6.20's at 127/128 mph. Didn't care about et, but mph should have come up since I lost 300lbs over the winter
In the two weeks between then and yesterday I found a fueling issue with cylinder 4 and now had all firing again. I also saw intake temps in the 150* range, so I installed a methanol kit with 1250cc worth of nozzle. I also pulled the gates and verified operation, cleaned them all up and reinstalled with the 4psi spring
Yesterday, went back to the track. Intake temps are now in the 130* range, egt is in the 1300* range and car runs amazing, but still creeeping. This 4psi spring gets me about 10 on the two step and today it's running 20psi at the 1/8th mile with 0%dc. I also installed a header pressure sensor and at 20psi I'm seeing 30psi in the header
So this morning I checked the mac valve. In test mode I commanded 0dc, I'm able to blow through the top port and out the vent, and at 100% dc I'm able to blow through the top port and out the boost reference port, so that's working and not creating a closed pressure spot preventing the gate from opening. I then pulled all the lines off the Wastegates themselves, put a bit driver in the top port and used my test setup on the bottom port. At 5psi the gate begins to open and at 8psi both gates are fully open
What am I missing here? The car ran a 5.95 and 134mph at this airport which is 6mph faster, which I expected from the weight loss, but have zero control on boost. If I could control it, ramping it in faster would be nice and even letting traction control pull some for me would be nice. Looking at the data, the 134mph run I started hazing the tires about the 400 mark and went through the traps at 135mph front vss and 170mph rear vss
What can I try, datalog or tear into next. I have a 1/4 mile event planned in two weeks. I thought about trying my standard cover to see, and I see lots of non intercooled setups working just fine
Not sure of your total fueling but being too rich will cause more boost and the same with not enough timing. It may not even be that you're rich but you have increased your entire exhaust volume with additional fueling (meth). If your wastegate setup is marginal any decrease in backpressure may be just enough to not control boost. You eliminated an intercooler and piping so as well as a more efficient race cover this could have easily lowered your drive pressure. Did you log backpressure last year? Post a pic of your wastegate angles. It could be a combo of running rich, not enough timing and less backpressure with non optimal wastegate location.
Just did some testing. Idled the car and used my compressor setup to open the gate, just to verify that there was exhaust movement. And there was. So I left my bit drivers in the top of the gate and brought the car up on the two-step. Confirmed gates open
I'll attatch my gate placement and tinting table My dyno guy says I'm a bit low on timing, but not really low
No data from last year on back pressure
Afr is pretty solid at mid 11 afr. It averages an 11.3
The meth just added some cooling, and I had some other issues to fix so the fuel table was tuned with the meth installed. But had the issue before the meth the weekend befor
I've watched denmahs video using the same size gates with pretty not ideal locations and after two got installed he had beautiful boost control on e85
My hot pipe darn near minicks the intercooler setup, it was water/air in front of the alternator
I still have the standard cover I could tap for my meth nozzles, but over all seems weird that I go from 70%dc to make 18lbs to zero darn near making 20lbs now
Egt data is in the 1300 range, is this a function of fuel and timing. Could adding timing make it colder?
Edit, the timing strap on the plug is just rounding the corner, so it seems close, heat range of 7 seems to be correct too
Last edited by Nathaninwa; 04-30-2017 at 07:20 PM.
I can't really tell from that picture of where your gate merges into the hotside and what angle its sitting at. You said you have 20 psi boost and 30 psi drive pressure, that is very low back pressure for that turbo so your setup seems very efficient. Wastegate placement is critical especially seeing as you are only seeing 1.5:1 which is far under what a lot of guys are seeing. In Denmahs setup did he have an a2a intercooler that probably had 2-5 psi boost restriction in turn raising drive pressure? I'd look into an 8 or 9 range plug no reason to really run a 7. Rockauto has by far the best prices on NGK plugs I've found.
Being rich or low on timing won't have a huge impact on your overall boost probably only a few psi difference. On a car I tuned yesterday on pump gas the initial tune was super fat (under 10:1 afr on gas maxed out wideband) and boost was 13.5 psi. After getting fueling in line the boost dropped to around 10 psi from what I can remember. Depending on EGT location adding timing could lower EGT but also pulling timing and being super rich with a lot of fuel burning in the pipe will see a high egt. EGT is a tough one on a gas turbo engine. In the Diesel world fuel = heat, if you have high EGT you need to add airflow (boost) to bring EGT down or remove fuel out.
Last edited by Nitroused383; 04-30-2017 at 08:29 PM.
My gates are like in the first pic with poor flow! Bummer, it would be hard to move them and still have access to the gates if a spring change is needed
My egt probes are all like 1-1/2 inches from the header flange
I've posted about this on the megasquirt board and it wasn't recommended, the only non projected and iirc projected tip plug for an LS that is resisted is the br7ef/s. Anything colder is a race plug and non resistor
For testing I could put my intercooler back in and give it a try
Last edited by Nathaninwa; 04-30-2017 at 09:53 PM.
For the time frame, just talked to my dyno guy. I'm going to install the water/air core and test it alone at 5 psi while monitoring pre intercooler pressures. If this works, we are going to trade for an ETS air to air core and since we are heading down there this coming week I'll have time to install it over the weekend
If you need a resistor plug with megasquirt you can get a ngk -9 iridium plug I'm not sure the exact number. Otherwise ngk sells resistor end caps for your plug wires so you can run a non resistor plug, Zach brown has posted about them several times.
Just got the a/w cooler in. If the weather is good I'll make a test hit tomorrow
Plumbing will be tight for the air to air setup, I'll need to weld on a 180* elbow onto the compressor housing but the rest will be good flowing I'll just need to find room for my tranny cooler
Yea, there are shitloads of 8 resistor plugs, those are just a few. Some cheaper than others of course, but not all non-projected type.
Just checked mine the other day and I've Denso IQ24's in at the minute. Basically equivalent to that BKR8EIX. Both are regular projected.
Although if memory serves right, IK24 might be better, as the IQ is a Jap version which the main body is a fraction shorter so if your socket uses a rubber insert to catch it...this might not reach.
Annoying first time I tried to remove them, and had to use a different socket or the plug had a habit of falling out.
Difference is only like 2mm or so !
Some ecu setups will be fine with non resistor, but typically for an EFI setup they want resistor plugs as it helps reduce interference. But if you arent having interference issues...then never worry about it.
As for gate flow etc. Even if the pipework seems poor for flow, a larger gate may well be the solution.
Whilst a crude test, remove the gates and see if you can run them like that for a test. It'll be noisy and messy though, and ensure the open pipes cannot burn anything.. Or maybe create a temporary pipe to vent them somewhere safe.
Or just fit larger better quality gates, not Chinese ebay crap.
What sort of flow path do the gates have ? What is the valve like ? How far does it actually open ?
I guess that with the old IC in place there was enough of a pressure drop across the core to make boost more manageable. Now that you removed the IC and put a nicer housing on it, the turbo is making much more steam at drive at like drive pressures and running away. Do you have dump tubes on the wastegates? As mentioned that positioning is poor, but rearranging/increasing size of the dumps alone may fix the issue. Boost control gets more sensitive the less drive pressure there is. Might try a pass with the WG dump tubes removed.
Creep is probably a good thing, means your system is more efficient. Seems like adding the old IC again is going backwards and raising your drive pressure. If you install a better IC core, it may lower the pressure drop across the IC core enough that you’ll start boost creep again.
Could try a larger gates or larger/no dump tubes since you are using china stuff anyway. Could also put another 44mm on the turbo housing itself if that’s easier. Fixing the issue of gate placement would be best.
Would you be able to make a small merge off the hot side to each gate instead of having a 90 degree turn into the gate? Think of it like an exit ramp instead of a tee intersection (sorry for the bad example). The only reason I ask and mention it, is I see space is a premium and maybe you can re-engineer the gates' flow path without actually moving the gates.
Good ideas here. My Wastegates merge from 1-3/4 into a single 2-1/4 pipe that dumps by the front tire. At this point, with an efi swap and overdrive planned for my tow rig, I just don't have the time to tear apart my turbo kit. If this old a/w cooler does the trick, I have a pretty efficient (read that as the same core on my 2jz car sees 2psi drop at 30lbs and air temps only climb about 10* in a 1/4 mile pass). It's an ETS 12x24x4 core. Mounting that and replimbing at this point is easier than redoing the gates. Sounds like when this works, this will be on the winter upgrade list
Spark plugs. Is there any concern with a projected tip? I run an iridium 8 projected on my 2j and seems ok at 850whp. I like to stick with ngk
Testing, weather dependent today. If it's rain, I'll bring it on the transbrake and see what happens to boost compared to other logs and see what the preturbo pressures are
Weather was crap after work today. Went to the local area and spin city, but was able To roll powerbrake it. With the intercooler installed I was able to go get 3psi in the intake and 6psi Preintercooler
Brought it up on the transbrake and car makes a solid 5.5psi, but also had 5.5 psi preintercooler
So I hot piped the car, and brought it up on the transbrake, again it made 5.5 psi at 4000rpm just like with the intercooler installed
I've ordered the 3.5 inch piping for the Extreme Turbo System intercooler
Moving along with this project. Area is cut open and ready for the intercooler ill get today. Had enough 3-1/2 tubing to start the piping process off the turbo. Had minimul room to snake this size through and clear what it needed to
Have intercooler, old tanks cut off and new ones almost mocked up. Cross member is welded in for it sit on and I'll run some support bars off the top to the core support bar
Almost time for daughters baseball so I'll update later tonight with more installed pics
And hoping the FedEx guy brings me more intercooling piping
04-30-2017, 11:08 AM
From boost control to none and huge creep 
