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93 BB base FD build-up
My car started out as a one owner bone stock 93 brilliant black base model with the tan leather option. I purchased the car in 1997 and it remained bone stock until 1999 when the starter ring separated from the flywheel and I found that a lightweight aluminum flywheel was cheaper then replacing the stock one.
Around the same time I got into autocrossing with the SCCA. As luck would have it, the lightweight flywheel kicked me out of stock class and they put me in ASP. I ran my first 6 events on street tires and thoroughly got my ass kicked in my basically stock car. Like all new people to autocross, I was sure the car was the problem and not my driving so I began the upgrade path to get the car fully prepared to ASP rules. It took me about 6 months and a fair amount of cash to make the transition to a fully prepped car. Of course that was when I learned that my performance problem might just be the driver :). Here is a break down of the mods the car went through back then: Koni Sports converted to Coil over’s and double adjustable by TriPoint engineering.Picture from that time frame: http://www.tweakit.com/rx7/chadwickrx7.jpg In 2005 they change the rules for the class and I added a few more things, some of which I already owned for years but couldn’t use because of the rules: Apexi PowerFCPicture from 2006 http://www.tweakit.com/rx7/chadwickrx72.jpg My current build up is moving the car from ASP to SM2, which is pretty much wide open as far as rules go. I’ve always wanted the 99 front bumper on the car, which I couldn’t do under the Street Prepared rules so it pushed me to move classes. Engine build My goal with the engine build up is to achieve maximum low end torque. In as such I have stayed away from changing the timing of the ports. I’ve spent hours talking to other builders about porting and all that I talked to agree that street and race ports move the power band higher up the RPM range. So my goal was to increase flow without changing timing. Rob at Pineapple racing was the most helpful in me determining the best way to accomplish my goal. Most of my port work involved cleaning up the trash left behind by the casting process and machining of the ports. Hours were spent working on the bowl shape and maximizing the air flow through the runners. Overall I’m confident this is the right path, but only the dyno will tell if I have accomplished my goal. Secondary Port: http://www.tweakit.com/rx7/sport.jpg Primary port: The white dust spots are left over from the grinding grease I use during porting. It will wipe right off. http://www.tweakit.com/rx7/primaryport.jpg Gasket matched intake runners: http://www.tweakit.com/rx7/intakeport.jpg http://www.tweakit.com/rx7/intakeport2.jpg http://www.tweakit.com/rx7/gasketport.jpg If you look closely at the porting, you will see some areas are polished and some areas left ruff. I believe that you should polish before fuel delivery and leave it some what textured after. The reason behind this is to keep the fuel atomized as much as possible when it is delivered to the combustion chamber. A good example is the last picture with the gasket in place. Notice how much brighter the primary intake runners (middle) look in the picture compared to the secondary runners (outside). The reason is fuel is delivered to the secondary runners from the lower intake manifold so they have not been polished. The primary runners are polished right up to where the fuel is delivered inside the intermediate housing. I’m not talking a huge difference between them, just enough to keep the gas from sheeting down the side and entering the housing in drips. I’m also using 9.7:1 compression rotors and an RX8 eccentric shaft. I picked the 9.7 rotors because of the extra grunt they will give me down low and the fact that they weigh the same as the stock 9.0:1 rotors. The RX8 eccentric shaft is a direct replacement for the 13B-REW but weighs .4 lbs less. I should note that the RX8 shaft’s journal diameter is .0003 less than a stock 13b-rew eccentric shaft. For me this is not a problem as I wanted the extra bearing clearance for running the engine past 8k rpm. I sent the whole rotating assembly off to Racing Beat to have balanced, I want to use CLR but Carlos was swapped with work and I couldn’t live with the turnaround time. Just for your information all 13B-REW counter weights do not weigh the same. Every one of them are balanced at the factory to the actual assembly they are in, so if you have to change out any of your original rotating parts for any reason, you should have them rebalanced. In my case this time I had to buy new front and rear counter weights as both were to light to balance out correctly with the “D” weight rotors I sent. Balanced rotating assembly: http://www.tweakit.com/rx7/balanced.jpg Close up of balancing holes http://www.tweakit.com/rx7/balanced1.jpg Exhaust, Upper intake and Lower intake manifold after ceramic coating. http://www.tweakit.com/rx7/bling.jpg One of the weak points with the stock intake is the unequal runners of the lower intake manifold and the turbulence caused by the emissions components on both the lower and upper intake manifolds. Because of this I choose to use the Xcessive Manufacturing lower intake manifold and a JDM upper intake manifold. I consider using a 13B-RE upper intake manifold as they are reported to increase torque but I decided not to at this time because of the extra fabrication required. The Xcessive LIM is a work of art; the intake runners are of equal length and it doesn’t have any of the stock LIM oddities. The wall thickness is also an improvement and will allow for some very generous porting. Note that the stock LIM is the cause of the front rotor being lean at idle and the rear being lean under boost. It is the most likely reason most FD’s blow the rear Apex seals even when the air fuels look safe. Shot of the irons, housings and assembled rotors sitting on the bench: http://www.tweakit.com/rx7/prerotors.jpg Front rotor and housing installed, putting a thin layer of Hylomar on the rotor housing: http://www.tweakit.com/rx7/engine1.jpg Rear rotor and housing installed, again laying a thin layer of Hylomar on the housing (almost caught Brians face in this shot :): http://www.tweakit.com/rx7/engine2.jpg Almost complete short block: http://www.tweakit.com/rx7/engine4.jpg Brian (aka Wilson) setting the torque on the engine studs: http://www.tweakit.com/rx7/engine3.jpg http://www.tweakit.com/rx7/engine5.jpg Test fitting the Turbo with the XS LIM, had to modify the oil and water supply lines to clear the side of the LIM: http://www.tweakit.com/rx7/engine6.jpg http://www.tweakit.com/rx7/engine7.jpg http://www.tweakit.com/rx7/engine8.jpg Porting the head: http://www.tweakit.com/rx7/miatahead.jpg :D Build completed: http://www.tweakit.com/rx7/engine9.jpg http://www.tweakit.com/rx7/engine10.jpg Sneak peek at the airpump deletion pulley I'm fabricating: http://www.tweakit.com/rx7/pulley1.jpg http://www.tweakit.com/rx7/pulley2.jpg Engine in car: http://www.tweakit.com/rx7/engine11.jpg Fitting intercooler piping: http://www.tweakit.com/rx7/engine12.jpg Install almost complete: http://www.tweakit.com/rx7/engine13.jpg |
Ready for first startup:
http://www.tweakit.com/rx7/engine15.jpg Engine is running, adjusting fuel pressure: http://www.tweakit.com/rx7/firststart.jpg First startup smoke cloud: http://www.tweakit.com/rx7/firststart1.jpg Using an Xcessive LIM with 99 or stock twins: Getting the 99 twins to fit with the Xcessive LIM took a little bit of work. There are several things that don’t allow them to bolt right up. Here is a list of modifications that need to be made: Oil and Water supply lines need to be bent to clear the front side of the LIMCurrent build: Engine & Drive train 13B-REWFuel pressure regulator mounting (Brian (aka Wilson) is a master at making custom mounting brackets) http://www.tweakit.com/rx7/FPR.jpg Old school jacobs!: http://www.tweakit.com/rx7/jacobs.jpg Mazdaspeed Power Plant Frame: http://www.tweakit.com/rx7/ppf.jpg Battery Relocation: Similar to this write up , but I use a PC680 battery and a 3 constant hot, 4 ignition switched fuse block. http://www.tweakit.com/rx7/battery.jpg Harness: Brian and I routed the FJO and Dual EGT wiring through the stock harness. The FJO injector driver will be mounted behind the kick plate with the PowerFC. http://www.tweakit.com/rx7/harness.jpg Body: 99 front bumper (F138-50-031A-AA)Test fitting 99 bumper http://www.tweakit.com/rx7/99facelift1.jpg Test fitting 315 rear tires w/ 10" wheels: http://www.tweakit.com/rx7/tire.jpg 315 tires mounted on wheels with new outer lip test fit. http://www.tweakit.com/rx7/rear1.jpg Brian and Andrew taking measurements to mount the dual element wing. They are both Mechanical Engineers so I think I’m in good hands.: http://www.tweakit.com/rx7/wing1.jpg Installing lower wing element: http://www.tweakit.com/rx7/wing2.jpg Stantions after powder coating (Thanks Andrew!) http://www.tweakit.com/rx7/pcwing.jpg Fitting second wing element and side plates http://www.tweakit.com/rx7/wing3.jpg http://www.tweakit.com/rx7/wing4.jpg Interior Corbeau FX1 composite seat w dual lock slider (Driver)Wiring up all the gauges and carputer before: http://www.tweakit.com/rx7/wiring1.jpg After: http://www.tweakit.com/rx7/wiring2.jpg http://www.tweakit.com/rx7/wiring3.jpg Carputer and LCD screen, ran into two issues here. One is that there is a support that runs 6.5 inches behind the radio dins which I had to cut out with a dremel as the carputer and LCD are both 7.5" long. The other is the LCD hits the fan speed dial and does not tilt back far enough. I will have to find a spacer to move the mount out about 1/2" http://www.tweakit.com/rx7/carputer1.jpg Tripower gauge pod w/ Dual EGT and Airfuel gauge http://www.tweakit.com/rx7/tripower.jpg Corner balancing and Alignment: Pictures of her on the rack getting a corner balance and alignment: On the scales: http://www.tweakit.com/rx7/cb1.jpg Alignment time, look at that big ass wing! http://www.tweakit.com/rx7/align1.jpg Here I am setting front camber and caster, Brian (aka wilson hiding behind the tire) http://www.tweakit.com/rx7/align2.jpg She came in at 2918 with 250 lbs of weight to balance out for me so she is right at 2668 lbs without my oversized ass. We dialed in a 50/50 split on the corner weights and for the first time the rear weighs more than the front. Split front to rear is 49.3% front, 50.7% rear. It must be the big wing making down force even when the car isn’t moving. My alignment specs are as follows: Front Camber -2.2 Front Toe .14 Caster 5.1 Rear Camber -2.3 Rear Toe -.16 Misc Fuel tank surge coverWidefoot swaybar mount installed: http://www.tweakit.com/rx7/wf.jpg Zerk fitting on lower control arm to lube Unotainium bushings: http://www.tweakit.com/rx7/zerk.jpg Strapping her down on the dyno for engine break in and tuning http://www.tweakit.com/rx7/dyno1.jpg Brian driving her to Memphis. Well at least that is our joke he really never left the dyno but he feels better when he has a goal. http://www.tweakit.com/rx7/dyno3.jpg Four hours later let the tunning begin: http://www.tweakit.com/rx7/dyno2.jpg After about 15 heat cycles and 150 to 200 miles of engine break in on the dyno we started tuning. I have the restrictor pills removed to limit boost and allow for a little more break in time without a heave load. We worked our way up the scale through multiple runs. Brian did a masterful job controlling the amount of boost by modulating the throttle. We made 2 or 3 runs at each new level until we were happy with the AFR. When we started the day I pulled the map from my last motor and added 20% more fuel and pulled 5 degrees timing across the entire map less the idle area which had already been dialed in. Tuning the vacuum area required removing about 5% of what I had added to get to my target AFR. I also pulled another 3 degrees out of most the vacuum area based on the EGT’s we were seeing. In the boost areas I only had to take out about 2%. This tells me that my porting and the use of the Xccessive LIM was the right choice as she breaths very well, especially under boost. Something that I found surprising was with the pills out she was hitting 12psi on the first turbo, then dropping to 10psi when the second picked up. This same exact setup could only muster 7/7 on my previous motor. The first turbo spools up wicked fast. It caught Brian by surprise on one pull when we were just tuning vacuum. He slammed the throttle shut so fast that she shot out a nice fireball. Brian says that my eyebrows still look the same, but I’m not so sure and I keep getting whiffs of burnt hair. We ended the day with a quick pull just to see what she was putting down and get a look at the torque curve: 267 rwhp and 217 torque at 10psi with Brian letting off at 6800 rpm. I think you will be surprised by the torque curve when you see the dyno sheet, I know we were. Let me just say that in this case I have a hard time calling it a curve. We still have a lot of tuning left on the AFR and optimizing the timing but over all she is running very good and made her debut at the autocross today. Off to the races: http://www.tweakit.com/rx7/race1.jpg |
Great build thread! I personally don't like the 99+ bumper, but the rest of the car is coming along nicely. Great info on the rebuild, and I like the idea of what you're going for with the porting/going for torque.
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Its looking good Dan, is this the car your going to use the FEED side skirts on?
Jonathan |
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Dan |
Added pictures of the porting, tire fitment, gauges and carputer above. Also wrote a little bit about the porting.
Thanks, Dan |
what size wheel are you using for the 315's and how much modification did you have to do for the 315's to fit? Was it just an aggressive fender role or did you have to tub it out or flair the fenders some? I'm planning on running 315's on my car with the burnout kit so was curious how much work my body man is going to be in for.
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Good porting pics, looks good :)
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Dan |
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Very very impressive Dan!
Can you provide more details on the wheel and tire sizing, as well as modifications required for fitment? thanks! Rich |
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Thanks Rich Tire on there now is a Kumho Ecsta V710 R compound tire, size is 315/35ZR17, height 25.4". I will be running 275/40ZR17 up front, they are also 25.4" so I will not be picking up any rake from the tires. Dan |
Looks REAL nice Dan, I think those ports will work just fine! Good job!
-J |
Very Nice Dan!
When things settle down, I guess I'll transfer my build thread to here:) |
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Get busy damn it !!! :D :001_005: Dan |
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