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 FAQ: What will fit on a 4cl from a V6 MX-3? 
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Post FAQ: What will fit on a 4cl from a V6 MX-3?
Many people ask what will fit on my 4cyl MX-3 from a v6 mx-3?
Well Vaughn has put together a page that tells just that. Thanks Vaughn.

<small>[ September 30, 2004, 01:16 PM: Message edited by: Custommx3 ]</small>

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February 05 2003, 2:01 PM
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Post Re: FAQ: What will fit on a 4cl from a V6 MX-3?
Some people have been E-mailing me, asking what parts can been swapped from a MX-3 GS to their base RS model and what can be adapted from other Mazda models to the MX-3RS, Protege and Ford Escorts. Here are a few things to look for either new or used.


Rear Performance Rod:

This is the lower brace that ties the left and right lateral link arms together to reduce the inward flex of the rear wheels. Honda owners seen to pay highly inflated prices for what Neuspeed and Lightspeed call a "lower rear strut bar". You could probably pick up one of these bars and the longer bolts that go with it, pretty cheap at an auto recyclers, clean it up and paint it red or yellow and tell people you spent a lot of money. Not only will this upgrade work on the MX-3RS but also the Protégé, 323 and 90+ Escort & Tracer


Transverse Member:

This stamp steel crossmember basically ties the bottom end of the front suspension together. Again Neuspeed and Lightspeed sell a lower front strut bar kit to the Honda owners. (big bucks for this to - no surprise here) the Factory crossmember may not look as cool as a Neuspeed or Lightspeed kit but serves the same function and is a whole lot cheaper. The holes are pre-drilled and tapped on the MX-3RS but Protégé and Escort owners may have to break out the drill and a 12mm tap.


Steering Rack:

The rack and pinion steering on the GS has a faster ratio. 2.7 turns of the steering wheel from lock to lock verse 3.5 turns on the RS, Protégé or Escort. I wouldn't recommend swapping this item unless you have to replace the steering rack due to an accident or if you are a diehard autocrosser, because it would require dropping the whole front cross member assy. or pulling the engine. Either way it's a lot of work.


Rear Disc Brakes:

It would be possible to swap to the disc brake from a GS in place of the drums on RS. You will need the complete rear spindle assembly, wheel bearing assembly, rear calipers, rotors, flexible brake lines and park brake cable. In addition you will also need the bigger bore master brake cylinder and front because four wheel disc brakes requires more fluid pressure and volume to operate rear calipers than it does to operate drum brakes. Unless you are racing on a tight circuit course where you are on the brakes often there is little advantage to swapping to discs. The disc brake assembly add a lot of additional unsprung weight and do require much more maintenance as the park brake actuator level has a tendency to stick in the engaged position.

Swapping 60Amp (RS) for 90Amp (GS) alternator:

I notice a couple of weeks a go, on my friend Ron'sProtege that the engine RPM's would change each time the lights flashed when the emergency flashers were on. The stock charging system was having a hard time keeping up to the electrical requirments of the car. I gave Ron my spare 90Amp alternator to see if that would fix the problem of the engine speed dropping everytime he increased the electrical demand on the car. He had to swap pulleys from the old 60Amp to the 90Amp alternator because the "B" engine use a V-belt where the "K" engine use a serpentine belt. Also the Mounting bolts attach from the opposite side. Once the alternator is mechanically installed the wiring just plugs in. Now with the charging system having more capacity it uses less engine horsepower to operate all the electric systems.


Larger V-6 Throttle Body:

The stock (K08) 1.8L V-6 throttle body is 55mm diameter. The (KL) 2.5L V-6 (MX-6/626) is almost identical to the stock 1.8L TB except for it has a larger 60mm bore and can be over bored to 65mm. You will have to swap the ISC valve that is attached to the Throttle body. Technically the ISC valve are also the same but the difference is the location of the vacuum ports and coolant passages are in different places.


High Volume In-Tank Fuel Pump:

If you are considering nitrous or forced induction you will probably need a higher volume fuel pump to get the additional fuel needed to the combustion cambers. The fuel pump from a Madza Cosmo (20B) is the only direct fit in-tank fuel pump upgrade. The Cosmo has never been available for sale in North America but the fuel pump is available from Mazda Competition Parts, in Irvine, California


RX-7 MAF Sensor on "B" Engines

One of the biggest bottleneck in making power with the "B" series engines is the restrictive "Trapdoor " type MAF sensor. The second generation RX-7 Turbo uses a higher flow sensor design that is easily adaptable to the "B" series ECU. The connector pin layout is the same and sensor values are more of less the same values. Being larger you will need an aftermarket cone filter adapter as the If your engine is unmodified and/or will not see anything above 6000rpm, then you shouldn't bother with this modification as it will be just a waste of your money. A header, muffler and a cone air filter will not increase the airflow requirements of the engine. You will only need the larger MAF if you have made modification that affect air flow requirements significantly like forced induction, over boring the cylinders, larger diameter valves, more aggressive cam lift/duration, porting the head, and a competition chip, etc. Some fine tuning will be necessary to correct the low/mid throttle air/fuel ratio by turning the small internal adjustment potentiometers inside the AF meter. You may also find you that you will need an adjustable fuel pressure regulators to correct the A/F mixture at WOT. Tuning will require a A/F ratio meter the make this adjustments correctly guessing at setting can be dangerous.


Larger Nippondenso (Bosch) Fuel Injectors:.

The fuel injector used on the "B" series engines can be swapped for larger 250cc or larger Nippondenso use on large displacement Mazda and Toyota 4 cylinder engines. Bosch injectors can also be used due to the fact that Nippondenso manufactures the injectors under license from Bosch.

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February 11 2006, 1:54 PM
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