When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Well so went to the track on Friday since itll be the last night I can for a few weeks and the results were mixed. I only got in 2 passes which were both slow as hell, First one I was scared pretty much and only gave it half throttle. Here is the first run, the guy next to me had no idea what he was doing, but the exhaust on this setup is definitely interesting, its definitely the loudest setup ive ever had. Not sure if thats from the gates being wide open the whole time or the 3 cutouts dumped under the truck.
Here is the log from run 1. The boost curve is going to be interesting...it leveled around 10psi which is what the blower pulley is, but you can see once the turbos come online it just keeps going up.
Compound setup, run 1
This is run 2 where I decide to be more aggressive. Boost really went up even with the gates wide open, so obviously boost creep is going to be a major issue even with 50mm gates right in the flow path dumped to atmosphere. Pretty sure my sensor maxes out at 28psi so not sure if the real number was higher. No video of this one. I started to push the heads on this run and the radiator overflow puked everywhere so I called it a night early. I have widebands on both banks so I can monitor that also. This is obviously going to be challenging. Compound setup, run 2
The good news is I spent the next day fearing the worst, but all the plugs looked ok and compression test on all cylinders looked ok so I threw in new plugs and started it up and drove around the block so I dont think the gaskets are compromised too bad. I need to get my meth system dialed back in also. First impression really driving it though is its going to take a lot of work, and the blower may be coming off sooner than later. Feels like its sucking through a straw before the turbos get going, so I am going to hook up my pressure sensor between the blower and intercoolers soon to see if its actually pulling vacuum when I nail the throttle from a stop (notice the lazy boost curve).
The good news is everything appears to be working somewhat as designed and did not have any failures besides the boost control. I bought a car trailer and installed a winch a few weeks ago, didnt think I would need it this soon but glad everything works ok. I knew boost control was going to be a challenge coming into this, so may upgrade the gates to 60mm ones at some point.
I'm interested to see the pressure between the turbos and blower. If the gates are open the whole time, do you think an extra 10mm will help enough to offset the cost?
Itll be a week or 2 before I have a chance to mess with it more. Offset what cost?
At this point I need to make a decision if I want to keep pursing this project or just pull the blower and go with the turbos. There are 2 main issues I see, boost control and blower lag. Boost control is the biggest one so I have been thinking about getting 2 of the huge 66mm precision gates and redoing the elbows with those. If that cant control the turbos then theres not a whole lot else than can be done besides slow down the blower which brings me to the next issue. If there is vacuum created between the blower and turbos during transitions then I dont know a good way to solve that one without being extremely complicated. If that is what is causing the blower to be not as responsive then thats a big bummer. If on the other hand thats not the case then it may be able to be fixed with tuning.
If I have to slow the blower way down to 4-6psi then I question why even bother at that point since it will hardly be doing anything and the low end wont be that much better than just with the turbos.
Offset the cost of bigger gates. If the current ones can't control the turbos, do you think the bigger gates will make enough difference to be worth the extra money and time?
Offset the cost of bigger gates. If the current ones can't control the turbos, do you think the bigger gates will make enough difference to be worth the extra money and time?
Well if they don't then the project is over and I'll just go twins, but there isn't a way to find out without actually doing it.
Itll be a week or 2 before I have a chance to mess with it more. Offset what cost?
At this point I need to make a decision if I want to keep pursing this project or just pull the blower and go with the turbos. There are 2 main issues I see, boost control and blower lag. Boost control is the biggest one so I have been thinking about getting 2 of the huge 66mm precision gates and redoing the elbows with those. If that cant control the turbos then theres not a whole lot else than can be done besides slow down the blower which brings me to the next issue. If there is vacuum created between the blower and turbos during transitions then I dont know a good way to solve that one without being extremely complicated. If that is what is causing the blower to be not as responsive then thats a big bummer. If on the other hand thats not the case then it may be able to be fixed with tuning.
If I have to slow the blower way down to 4-6psi then I question why even bother at that point since it will hardly be doing anything and the low end wont be that much better than just with the turbos.
If it does end up that there is vacuum during transition could a shot help? I sure hate to see the project end. Must be a way.
Nitrous would probably help, but in that case I would have to have it constantly armed and probably go through it quickly. This even applies to 0-50% throttle snaps not just 0-100, in which case you shouldnt use nitrous anyway. Not really sure of another way to fix it if it is a airflow problem...any ideas?
Jun 16, 2019 | 11:08 PM
