Something else I should mention, that hopefully come into play once the trans stands up and the suspension gets working - I installed a 3 port Mac valve for controlling the boost, and I'm not using it yet. The reason being, I believe, is my stupidly designed hot side. The idea of a 3 port Mac valve is that it can double the output (boost) that the wastegate(WG) spring generates. The sloppy guys (Denmah) uses a 4 port Mac that can almost quadruple the spring pressure allowing for much more control.
The issue I have is that my hot side entering the turbo is giant for a motor this small. I'm using a T6 1.32 AR which creates almost no back pressure. I thought this would be a great thing. And in the end it might be, but I'm not sure yet because I can't build boost fast enough presently. Most systems rely on dinky *ss turbos to make a HP number and the system is limited by the hot side that generates enough back pressure into the exhaust valve to choke the motor. So I thought I'd do the opposite ** (note **.) I have a very inefficient WG design - rather than running two pipes, one from each head into the divided turbo flange I merged them into a a piece of 4" pipe that I ovaled via a vice and welded onto the turbo flange. I then put the WG on the piece of 4" pipe. The result is that I have a WG spring that opens between 4-5psi of pressure (tested this several times). But because there is no back pressure to push on the WG, the WG doesn't open enough to have an effect until I reach 22 lbs of boost. Sounds almost impossible but we watched it on the dyno - between 21 and 22 lbs it will start dumping exhaust from the WG. I initially thought this would be disastrous, but my friend that owns the local dyno, talked me into leaving it as long as I'm running E85 for fuel. And he was correct. The only issue is getting up on boost at the line.
The solution, I think 😉 , is one of two things, the 3rd gear spool mod to act as a transbrake or using my last Terminator X output for a shot of nitrous off the line to get it spooled. Or perhaps a combination of both.
**I'll try to get some pics of my hotside that show off my poor fab skills with the 4" hotside going into the turbo while I'm waiting for the trans Dr. The following is my opinion from too much reading and what I've seen : backpressure in the turbo world is the enemy of top end power production. The idea that 'your turbo is too big' I disagree with in most normal builds. The current solution to reducing backpressure is high priced ball bearing custom turbo ($1800-3500). The budget program is Chinesium journal bearing stuff that generate too much back pressure on the top end or what I've got - a US made truck journal bearing unit for 12 liters of diesel displacement - a genuine Borg Warner 171702 made for a Series 60 Detroit that was mass produced for over a decade (less than $600). The issue I have to overcome is the initial lag, hence the transbrake and/or nitrous.
You can see in the vid the slow 60 ft and if you look close you can see I'm on the brakes before the 1/4 mile line - 11.7 at 105mph with a terrible 60' of 2.0. I believe that if I can get the 60' to anything reasonable such as 1.6-1.7 this will make 10's seem slow with a sub $600 turbo and dinky 294-325 cube motor in a 3700lb chassis. Time will tell, and I expect to have fun trying.
Please don't take any of my guessing as gospel - all my opinion and I could be wrong and will gladly accept that (but hope that I'm not wrong).
The issue I have is that my hot side entering the turbo is giant for a motor this small. I'm using a T6 1.32 AR which creates almost no back pressure. I thought this would be a great thing. And in the end it might be, but I'm not sure yet because I can't build boost fast enough presently. Most systems rely on dinky *ss turbos to make a HP number and the system is limited by the hot side that generates enough back pressure into the exhaust valve to choke the motor. So I thought I'd do the opposite ** (note **.) I have a very inefficient WG design - rather than running two pipes, one from each head into the divided turbo flange I merged them into a a piece of 4" pipe that I ovaled via a vice and welded onto the turbo flange. I then put the WG on the piece of 4" pipe. The result is that I have a WG spring that opens between 4-5psi of pressure (tested this several times). But because there is no back pressure to push on the WG, the WG doesn't open enough to have an effect until I reach 22 lbs of boost. Sounds almost impossible but we watched it on the dyno - between 21 and 22 lbs it will start dumping exhaust from the WG. I initially thought this would be disastrous, but my friend that owns the local dyno, talked me into leaving it as long as I'm running E85 for fuel. And he was correct. The only issue is getting up on boost at the line.
The solution, I think 😉 , is one of two things, the 3rd gear spool mod to act as a transbrake or using my last Terminator X output for a shot of nitrous off the line to get it spooled. Or perhaps a combination of both.
**I'll try to get some pics of my hotside that show off my poor fab skills with the 4" hotside going into the turbo while I'm waiting for the trans Dr. The following is my opinion from too much reading and what I've seen : backpressure in the turbo world is the enemy of top end power production. The idea that 'your turbo is too big' I disagree with in most normal builds. The current solution to reducing backpressure is high priced ball bearing custom turbo ($1800-3500). The budget program is Chinesium journal bearing stuff that generate too much back pressure on the top end or what I've got - a US made truck journal bearing unit for 12 liters of diesel displacement - a genuine Borg Warner 171702 made for a Series 60 Detroit that was mass produced for over a decade (less than $600). The issue I have to overcome is the initial lag, hence the transbrake and/or nitrous.
You can see in the vid the slow 60 ft and if you look close you can see I'm on the brakes before the 1/4 mile line - 11.7 at 105mph with a terrible 60' of 2.0. I believe that if I can get the 60' to anything reasonable such as 1.6-1.7 this will make 10's seem slow with a sub $600 turbo and dinky 294-325 cube motor in a 3700lb chassis. Time will tell, and I expect to have fun trying.
Please don't take any of my guessing as gospel - all my opinion and I could be wrong and will gladly accept that (but hope that I'm not wrong).
