84 12a bridgeport drift car
#101
I'm curious as to why you didn't properly duct the oem radiator opening before you cut the filler panel and ducted that? With how car back you radiator is mounted I bet all the air was going right around it.
The oil cooler will obviously benefit from the same treatment if you ever find yourself with oil temp issues. Coolers only work with a pressure differential.
Anyways, awesome build, I always like seeing people do everything themselves.
The oil cooler will obviously benefit from the same treatment if you ever find yourself with oil temp issues. Coolers only work with a pressure differential.
Anyways, awesome build, I always like seeing people do everything themselves.
#103
Well I got a few things going on with the car I have to sort out...
I got a new tune on the carb thanks to the knowledgeable guys at mazdatrix, stepped up the fuel and air but stuck with my f7 tubes for now. Had issues with the high flow glass needle and seat overflowing the bowl (float not shutting it off,) looks like the brass end is damaged and ball doesn't move freely so I need to order another one. Did drive it with the new tune though and it rips! Let it go to 9k rpm and it was fun to feel the power band kick in. Unfortunately the alternator pulley for the gilmer drive broke the front lip and shucked the belt off so I ordered the double v belt setup instead, need to get that going. Looks like I need a new intake manifold gasket too, leaking coolant that pools on top of the manifold (leaking while engine is cold,not running?) don't know... A little nervous but I pulled a plug and didn't see anything so I'm guessing it's just the o ring/freeze plug area leaking... Hope it's not a housing but from what I've read seems like the intake manifold is most likely the culprit. I'll get it going when I have time and post updates. Any advice on the coolant leak is welcome!
I got a new tune on the carb thanks to the knowledgeable guys at mazdatrix, stepped up the fuel and air but stuck with my f7 tubes for now. Had issues with the high flow glass needle and seat overflowing the bowl (float not shutting it off,) looks like the brass end is damaged and ball doesn't move freely so I need to order another one. Did drive it with the new tune though and it rips! Let it go to 9k rpm and it was fun to feel the power band kick in. Unfortunately the alternator pulley for the gilmer drive broke the front lip and shucked the belt off so I ordered the double v belt setup instead, need to get that going. Looks like I need a new intake manifold gasket too, leaking coolant that pools on top of the manifold (leaking while engine is cold,not running?) don't know... A little nervous but I pulled a plug and didn't see anything so I'm guessing it's just the o ring/freeze plug area leaking... Hope it's not a housing but from what I've read seems like the intake manifold is most likely the culprit. I'll get it going when I have time and post updates. Any advice on the coolant leak is welcome!
#104
I wouldn't stress, it's more than likely your intake. I had a similar problem last year and replacing the seals fixed it!
https://www.rx7club.com/1st-generati...-read-1081762/
https://www.rx7club.com/1st-generati...-read-1081762/
#105
Good news! I pulled the intake manifold and it was definitely leaking from the 20mm freeze plug in the front housing (I could squeeze the upper radiator hose and see coolant seeping out.) so I drilled and tapped the freeze plug to accept a 3/8ths bolt and it pulled out no trouble at all. Cleaned the hole and put a light coating of JB weld on the new freeze plug and set it in. Port matched a new intake manifold gasket, and reinstalled the intake with a layer of hylomar to help set the gasket better. Going to attempt a fix for my broken gilmer alternator pulley (turn a new front lip washer and weld that on) before I swap everything out for the double v belt setup. So hopefully that works and the weather holds enough for me to get one last rip around and not spend all winter nervous that it leaks!
#110
Its a duraflex one off Ebay, nothing fancy. I think its the M1 model. Didn't fit super good, but made it work. Had to trim for the front fender flares too.
Few updates:
Been driving the car a couple times this year, couple niggling issues to take car of still. Oil cooler is leaking at the fitting where it threads into the cooler so I need to weld that in place. Also having some oil seep from the base of the oil filter area, guessing its from the high oil pressure from the race regulator setup, 120psi and synthetic oil makes for a tough seal. Going to switch to a double O-ringed filter and see if that helps stop that.
Just recently been chasing fuel pressure drop, took it for a run yesterday and performed great the first 10 miles and then leaned out so I checked fuel pressure and sure enough it dropped to 3psi at the regulator when I had it set at 4.5psi. No damage to the car, wasnt driving it hard or high into the RPMs but I noticed the air/fuel ratio reading 13-14s under load which isn't normal for this carb and jetting. Going to check the filter in front of the pump (holley blue) and perhaps change the regulator. If not, then I guess the pump is going bad? Will continue to investigate but trying to keep it one variable at a time.
What's the preferred fuel system for a weber 48? Are you guys running 1 or 2 fuel pumps and what brands/models? Considering using a low pressure Aeromotive 2-5psi regulator for better resolution and then matching it with an aeromotive pump. I don't want to run a return style, have it deadheaded plumbed currently with -8 AN line.
#111
I would definitely change to a low pressure regulator, I think the error at least on the gauge would be pretty significant on the high pressure regulator. Maybe you can just replace the spring though and not the whole regulator.
#112
Good to see some updates man. Are you on Facebook? If so join my fb rx7 drifters page. Mine is finally done and performing amazingly.
Last edited by Maztang5.0; 05-15-17 at 12:36 PM. Reason: Same picture
#113
Fuel pressure and flow on IDAs can be pesky. I did the following and the issues have gone away for my 20-30 minute sessions at 80-90f ambient (EP 13B street port)
System:
Carter P4594 pump at the lowest level below the tank possible (a lot of guys run two rotary vane pumps in parallel, I still only run one). The 80s Mazda factory competition manual states for the IDA on a pport to ensure the pump can supply 1.5liters in 30sec = ~ 50gph.
Fram HPGC style fuel filter by the pump at the same elevation of the pump on the outlet of the pump
Holley 12-804 regulator at the same elevation as the inlet on the Weber, set to 4.5psi
Stock hardline under the car, -6 and/or 3/8s everywhere else, no return line
Good and open fuel tank/cell vent
You might measure the voltage at the pump terminals. With old, hacked up wiring originally my pump was at 2.5v lower(!) than the system voltage. Lower voltage requires more current at the motor windings which in turn heats the motor excessively. I now have a 10awg wire back to the pump through a high current switch and relay. Voltage drop fixed, pump even sounds better.
Next was to fab up some sheet aluminum heat shields to ensure that the pump/filter combo were shielded from any exhaust system heat that might be in the area.
System:
Carter P4594 pump at the lowest level below the tank possible (a lot of guys run two rotary vane pumps in parallel, I still only run one). The 80s Mazda factory competition manual states for the IDA on a pport to ensure the pump can supply 1.5liters in 30sec = ~ 50gph.
Fram HPGC style fuel filter by the pump at the same elevation of the pump on the outlet of the pump
Holley 12-804 regulator at the same elevation as the inlet on the Weber, set to 4.5psi
Stock hardline under the car, -6 and/or 3/8s everywhere else, no return line
Good and open fuel tank/cell vent
You might measure the voltage at the pump terminals. With old, hacked up wiring originally my pump was at 2.5v lower(!) than the system voltage. Lower voltage requires more current at the motor windings which in turn heats the motor excessively. I now have a 10awg wire back to the pump through a high current switch and relay. Voltage drop fixed, pump even sounds better.
Next was to fab up some sheet aluminum heat shields to ensure that the pump/filter combo were shielded from any exhaust system heat that might be in the area.
#114
Fuel pressure and flow on IDAs can be pesky. I did the following and the issues have gone away for my 20-30 minute sessions at 80-90f ambient (EP 13B street port)
System:
Carter P4594 pump at the lowest level below the tank possible (a lot of guys run two rotary vane pumps in parallel, I still only run one). The 80s Mazda factory competition manual states for the IDA on a pport to ensure the pump can supply 1.5liters in 30sec = ~ 50gph.
Fram HPGC style fuel filter by the pump at the same elevation of the pump on the outlet of the pump
Holley 12-804 regulator at the same elevation as the inlet on the Weber, set to 4.5psi
Stock hardline under the car, -6 and/or 3/8s everywhere else, no return line
Good and open fuel tank/cell vent
You might measure the voltage at the pump terminals. With old, hacked up wiring originally my pump was at 2.5v lower(!) than the system voltage. Lower voltage requires more current at the motor windings which in turn heats the motor excessively. I now have a 10awg wire back to the pump through a high current switch and relay. Voltage drop fixed, pump even sounds better.
Next was to fab up some sheet aluminum heat shields to ensure that the pump/filter combo were shielded from any exhaust system heat that might be in the area.
System:
Carter P4594 pump at the lowest level below the tank possible (a lot of guys run two rotary vane pumps in parallel, I still only run one). The 80s Mazda factory competition manual states for the IDA on a pport to ensure the pump can supply 1.5liters in 30sec = ~ 50gph.
Fram HPGC style fuel filter by the pump at the same elevation of the pump on the outlet of the pump
Holley 12-804 regulator at the same elevation as the inlet on the Weber, set to 4.5psi
Stock hardline under the car, -6 and/or 3/8s everywhere else, no return line
Good and open fuel tank/cell vent
You might measure the voltage at the pump terminals. With old, hacked up wiring originally my pump was at 2.5v lower(!) than the system voltage. Lower voltage requires more current at the motor windings which in turn heats the motor excessively. I now have a 10awg wire back to the pump through a high current switch and relay. Voltage drop fixed, pump even sounds better.
Next was to fab up some sheet aluminum heat shields to ensure that the pump/filter combo were shielded from any exhaust system heat that might be in the area.
Yeah I'm running a pretty similar setup, Holley 130gph pump mounted low on the side of the fuel cell, I forget what brand but I think a moroso or earls or some inline screen filter, then -8AN lines all the way up to a holley regulator on the firewall set at 4.5psi and then -6 from there to the carb. Fuel cell is vented, system has deadhead plumbing with no return from the regulator to the tank. I'll check voltage but I would be surprised to have an issue, as a wired the car from scratch with new wiring and components 2 years ago when it got built, relay for the pump etc.
Perhaps the 12-15psi regulator or whatever it tops out at doesn't have the resolution at less pressure and the spring varies off the setting. Seems odd that I would have to adjust it after setting it?
#115
Looking at your photos, I believe that same style of Holley regulator can come with a high pressure or a low pressure spring (like freeskier mentioned). The body and diaphragm are the same, to convert it to the low pressure you just need to buy the rebuild kit as it comes with both springs.
https://www.summitracing.com/parts/h...MobileSwitchNo
I run the low pressure spring. When I was having fuel pressure drop out issues Mazdatrix stated that they found the Holley regulators very seldom had consistent performance and that they would go through a bunch of them. They recommended the Aeromotive low pressure regulator.
https://www.summitracing.com/parts/h...MobileSwitchNo
I run the low pressure spring. When I was having fuel pressure drop out issues Mazdatrix stated that they found the Holley regulators very seldom had consistent performance and that they would go through a bunch of them. They recommended the Aeromotive low pressure regulator.
Last edited by Andrew-s; 05-17-17 at 12:26 PM.
#116
did you solve the problem? i found that running a return line, i'd get dips in pressure. Since I wanted a return line, i ended up fitting a 3-way valve before the regulator so i can run the fpr dead-headed or have some returning to the tank.
#119
Yes. I replaced the holley regulator with a Aeromotive return regulator and had much more consistent pressure. Happy with the setup now, but think the old Holley blue pump I was using is starting to die a little, will be upgrading with a new fuel pump shortly.
Been driving the car some, but still not happy with the steering so will be looking to build a rack and pinion setup soon. Picked up a quick ratio manual rack for a Mustang that I plan to use. Been sidetracked with work and other projects, building a tube chassis datsun 510 currently that I just got a 13b for (planning on big single turbo.) I should start a thread for that sometime
I'll get back with more updates when I have time, obviously with my extended absence on this forum I havent had much time for the internets recently
Been driving the car some, but still not happy with the steering so will be looking to build a rack and pinion setup soon. Picked up a quick ratio manual rack for a Mustang that I plan to use. Been sidetracked with work and other projects, building a tube chassis datsun 510 currently that I just got a 13b for (planning on big single turbo.) I should start a thread for that sometime
I'll get back with more updates when I have time, obviously with my extended absence on this forum I havent had much time for the internets recently
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