Icemark

Turbo and intake manifolds are identical to any other S5 13BT

NZConvertible

You may have bought an engine that someone had already done some work on, but there are no differences between stock Infini engines and other FC engines.

jreynish

iTrader: (2)

That is assuming that it is in the same seris turbo... for instance the Inifini IV will not have the same as an S5 N/A, nor will it have the same as an S4 TII.

NZConvertible

I thought that was pretty obvious...

DrEvil

I drive the Infini made in January 1988, imported from Japan. It has round back lights, typical of Series 5 but Series 5 come out later. Can anyone explain this?

Did all Infini models had round back lights? What were the differences between various Infini models I-IV?

NZConvertible

Is the rest of the car S5 or just the taillights? If it's just the lights they've just been swapped in by a previous owner.

Icemark

It is very very common to have a Japanese car that the owner has tried to make look like a newer model.

DrEvil

How can I tell the difference? I thought the only difference between S4 and S5 externally are the tail lights, and the engine has extra 10 kW in S5?

DrEvil

How can I tell the difference? I thought the only difference between S4 and S5 externally are the tail lights, and the engine has extra 10 kW in S5?

Forgot to mention ... my RX has a front spoiler which is nearly vertical and has mounted white fog lights.

Icemark

In 1989, halfway through its expected build life, the FC RX-7 saw a multitude of small refinements. Rotary engine technology had had continued its advance in the 3 years. The engines themselves used new lighter, higher compression rotors. The combustion recesses on the rotors were fully machined and chromed for heat control. With the machining, the compression ratios of each of the rotor's combustion chambers as well as rotor weight, could be more closely matched. The side seal thickness was reduced from 1.0 mm to 0.7 mm. The compression ratio for the normally aspirated models jumped to 9.7 and 9.0 for the turbo respectively (up from the 9.4 and 8.5). For both increased emission restrictions and better engine management the engine computer was speed was doubled.
On the normally aspirated (NA) engines the changes allowed the redline to be increased to 8000 RPM. A rotary valve was added between the intake tracks which started opening at 4500 RPM. This variable dynamic intake (VDI) valve enhanced the DEI (Dynamic Effect Intake) by altering the length of the fuel/air mixture path based on engine speed and load. The airflow meter was also changed from the flapper type to a linear type for cost, reduced air resistance and more precise measurement. The oil metering pump was changed from a mechanical pump to an electronic model for more effective lubrication and reduced oil consumption. These engine modifications raised the output of the NA 13B to 160 HP @ 7000 RPM and 140 lb/ft of torque @ 4000 RPM. The power band was effectively widened, giving more usable power at lower RPMs.

The Turbo II received a new turbocharger. Mazda called it the "Completely Independent Twin Scroll". The impeller was fed directly at the exhaust port. The Mazda press release in 1989 said: “This permits the powerful exhaust pulse generated by the opening of the exhaust port to directly hit the turbine blades without interference from the exhaust from the other rotor." This newer design resulted in reduced turbo lag and increased torque. The new electronically controlled wastegate allowed higher boost pressures and quicker response. The modifications resulted in the peak torque smoothed through the 2000 to 5000 RPM band. The horsepower also climbed another 18 ponies to give the revised Turbo II a Mazda claimed total of 200 horse power @ 6500 RPM and 196 lb-ft of torque at 3500 RPM.

The automatic transmission was now electronically controlled with a "hold" mode that allowed the transmission to be shifted manually in the lower three gears. Plastic end links and ball joint mountings were used on the sway bars to reduce noise, harshness, and vibration. Vehicle speed sensitive power steering became standard on the Turbo II, but in all GTU (base)normally aspirated models, a less accurate and cheaper engine speed sensitive power steering was used. The fuel tank was increased to 18.5 gallons across the line.

Inside the car, shifting was enhanced by a revised shift rod mechanism, and a shorter shift rod. Leather was used to cover the shift ****, steering wheel, and hand brake in all models except the GTU (base) model. The seats were re-contoured for better lateral support. The temperature, fuel, voltage, and oil pressure gauges were placed in round recesses rather than the pie wedges that were used previously and a minor revision was made to the instrument surround. The center console radio, shifter and Logicon (climate control) surrounds were slightly re-contoured with a new rubberized material and the Logicon itself getting updated icons for air direction. A new parcel shelf was added that hid items in the hatch area for GXL and Turbo versions. Controversial motorized seat belts became standard on the coupes in the USA and black became an interior color option with the gray interiors no longer available. The Limited Slip Differential found on the Series 4 GXL and GTU was dropped on the Series 5 cars to save weight and costs.

Exterior cosmetic changes included new a body trim strip that now matched the car color. The front bumper was slightly reshaped with the nose cap restyled with the word MAZDA embossed rather than the decal found on the '86-'88 models. On the upper level models integrated 55 watt fog lights were placed above the brake vents in the front bumper. The radiator opening was reshaped. A new slightly larger rear spoiler similar to the one found of the Turbo II and GTU in '88 became standard on all coupes. A slightly more rounded version of the Turbo II Aero mirrors also became standard across all models. On the Turbo II a new front spoiler and integrated side skirts replaced the 88 models Aero kit. And finally new tail lights finished off the exterior body changes.

TonyTurboII

I really hope you copied and pasted that from somewhere

Icemark

yeah, from my web page

White_FC

You sure about that? I was nearly 100% positive that was a 1986+ thing. (ie. only <1985 had the large side seals)

Icemark

89+ used the .7 side seals... perhaps you are confusing the side seals with the apex seals, which switched from 3mm in 84-85 to the 2mm in 86+

White_FC

No, not getting the two confused, I just went outside and measured the side seal slot on my S4 N/A rotors, and its definatly 0.7mm, not 1mm.

So I hate to say it but I think you may be wrong on that one point there..

Icemark

I'll reconfirm and post the results in the morning

White_FC

Cheers mate.

jon88se

Icemark,

According to car and driver the Infini IV comes with a larger diameter high performance exhaust and the car was quoted at 215HP. the car sat about 1/2 inch lower thanks to some slightly stiffer and lower springs and they also included a front strut brace and a momo corse steering wheel. US mags were allowed to test the Infini IV from mazda as a "prelude to the next RX-7" (FD)

Icemark

again from my website:

jon88se

hehe sorry ice, I just caught your post before about the car not being more powerful but you were just refering to the actual motor etc...being the same. I have an RX-7 history book with that article in it, the car looks beautiful!!

Icemark

The thing I think was most intresting, was that the braking was pretty noticably improved (8ft better from 60-0 and 14 ft shorter from 80-0) by simply lighter wheels and a better brake pad.

No funky crossdrilled or slotted rotors... simply wheel weight and brake pad upgrades.

jon88se

I'm sure the tires contribute...PZEROs are sticky hehe

MtnRacer

That article from the color history of the rx-7 is full of ****. Don't trust much of what it says. I've been working on a translation of a Mazda Infini III media brochure from japan. When I'm done, I'll post a PDF of it(translated) up here. It's really neat! About 14 pages of glossy photos, filled with text, should be a good read.

Steve

P.S. You can find the seats on auctions.yahoo.co.jp, they pop up every once in a while. Just need to find someone to ship them for you. Most of the parts I've been able to collect for my infini project car have been through online auction or personal contacts in japan.

TonyTurboII

You have the wheels?

MtnRacer

I've had a couple of chances to grab some. I passed on both sets. One set had a warped wheel(no good for the racnig I'm planning on doing). Another set was in Japan, but the asshat wanted an outrageous fee for shipping, couldn't talk him down. Eventually what I'll probably do is get some from yahoo.co.jp and have them shipped to my gf's place in tokyo, and then pick them up personally

Steve