website:www.grannysspeedshop.com

...Ordering Information...

'93-'95 3rd gen RX-7 / Chevy LT-1 V-8...

The purpose of this guide is to lay down the necessary tasks in an orderly fashion, to hopefully minimize the time and effort required to pull off a successful COMPLETE conversion.
Often times projects such as this are undertaken without a full understanding of what is involved. Hopefully, this summary of the steps necessary will provide individuals with the insight necessary to evaluate their own abilities, and help them come up with accurate estimates for both time and cost. Most hot rodder types will not need these instructions, but if they encounter a problem at some point, it's nice to know that helpful information is a close as their computer. This is a very easy swap that can be executed successfully by the average shade tree mechanic. No special mechanical skills or tools are required.

Many, if not most of the steps described here, are the same regardless of the engine choice. Injected engines such as the TBI, TPI, Vortec and LT1 will differ mostly with regards to electrical connections and fuel system plumbing. The main mechanical components and basic proceedures are generally the same.

If you would like more info on completing a smog legal conversion in California, CLICK HERE

Additions and corrections to this guide are encouraged, and will hopefully result in an evolutionary process that will eventually include EVERY detail required, right down to the wrench type, sizes, torque specifications and parts required to carry out each individual step.

...Realistic Expectations...

Effects On Maintenence & Reliability...
...If you already own a 3rd gen RX-7, then you already know about the rotaryís high maintenance requirements, have probably heard many stories about dealer service departments that lack proper training on rotary engines, and chances are, your beautiful sub 100k mile RX-7 is probably on itís 2nd or 3rd engine by now. These cars have not been sold in the US for over 5 years now, and replacement parts are getting scarce.
The Chevy engine, on the other hand, is perhaps the most common engine on the planet. Most any person with automotive experience has worked on one, and a well factory trained network of technicians exist from coast to coast. The modern Chevy engine routinely goes 100k between tune-ups, and replacement parts are among the cheapest and most common.

Effects On Performance...
...As you might suspect, the switch to a V-8 powerplane has an effect on performance too. The additional low-end torque makes the RX-7 very easy to drive, and is available throughout the RPM range. No longer will you have to excessively slip the clutch at a stop light to keep from killing the engine. No longer do you have to downshift, wait for your RPMs to come up and boost to build to pass a car. No longer will you live in constant fear of the dreaded boost spike. With the V-8, your power is always available.
If and when it comes time for an upgrade, things can really get interesting. Simple $100. modifications can result in 15-20hp increases, while spending a mere $4-5000. can get you up to around 500hp level. We are seeing low to mid 13 second 1/4mi times from mild smog legal engines with around 300-325hp, which is better than the high 13 second times that were possible with the RX-7ís stock twin turbo rotary engine.

Effects On Weight, Balance, and Handling...
...This is where you probably expected there to be a downside. People have probably told you that your handling and perfect weight distribution will be ruined with the addition of that big, heavy, american V-8. Just ask yourself if any of those so-called experts you have been talking to have any actual experience with piston-powered RX-7s. Weíve got the numbers to prove all those bystanders and spectators are just that....bystanders and spectators.
Here are some real numbers from a typical 3rd gen RX-7 converted to Chevy power:
The example car is a Ď94, which was not lightened in any way. The car was converted using a Camaro engine & transmission, a stock Ď96 LT1 (factory equipped w/ aluminum heads), and a T56 6speed. It has a full stock interior, as well as the stock air conditioning and power steering. The stock RX-7 cooling system was retained, as was the stock RX-7ís engine oil cooler. The car has the Camaroís stock cast iron exhaust manifolds, and is completely OBD-II smog legal, right down to itís cataylitic converter, EGR, and dual O2 sensors. The battery was relocated to the passenger side storage bin behind behind the seats. With a nearly full tank of fuel, the balance is a perfect 50/50, 1475 lbs front / 1475 lbs rear, for a total of 2950 lbs. About 90 lbs heavier than the stock RX-7 with itís TT rotary engine.

Engine / Transmission Choices...
...The RX-7's engine compartment / steering rack location somewhat dictates which engines are best suited for this conversion. The reason we prefer to use Chevy's rear sump small block engines?...engines with an oil sump located to the rear, such as the small block Chevy, allow for a lower and more rearward engine location while still clearing the RX-7's steering rack. Front sump engines, even engine's with a small front sump such as the Ford 5.0, would require either a far forward engine location or re-location of the RX-7's steering rack. Narrower engines such as pushrod V-8s will clear the RX-7's brake booster, while overhead cam engines such as the Ford 4.6 would require some creative re-working of the RX-7's brake system.
...If maximum smog-legal performance is your goal...we suggest using the liteweight Camaro/Firebird LS1 engine/transmission, as it is the best performing smog legal "certified" package that is both 50 state legal and easily adaptable to the RX-7 chassis. It has a very broad power band, with usable power at both ends of the power curve. This makes for a very user friendly power package that is well known and supported by repair and maintenance facilities across the US. Be warned however, that for street applications, the LS1 is a bit taller than the LS1, and will require hood modification to get the needed room. For a race application, lowering the steering rack is an optional compromise to maintain the stock RX-7 hoodline.
...If ultimate power is your goal...we recommend using the "old school" generic small block Chevy or a smog legal LT1 as a platform. These engines can be built to produce in excess of 800hp in naturally aspirated race trim, and over 1500hp can be possible with a supercharger or turbo system. For an all-out competition application, an aluminum block can be used to build a package as light as a LS1, but with more ultimate power potential. While there are LS1s out there built for ultimate power, they usually go to an iron block or use block filler to gain the needed strength, either eliminating any weight advantage or losing their streetability.

Skills Required...
...If you have a good grasp of things mechanical, do all your own automotive maintenance, have a good selection of tools and know how to use them, you are probably qualified to perform this swap.

Estimating Time For Completion...
...We have broken the conversion process down into smaller steps (links listed below). This allows the person actually doing the conversion to estimate the time he should allow depending on his abilities and resources.

Next page....

1....Introduction....

2....Considerations & Requirements....

3....Getting Started....

4....Engine / Transmission Installation....

5....Exhaust / Throttle Cable / Accessory Drive / Pulleys....

6....Cooling / Fuel Systems....

7....RX-7 Wiring Harness Connector ID and Circuit Locations....

8....Electrical System Modifications By Circuit....

9....Start-up / Troubleshooting....

10....Upgrades....

Back to 3rd gen Conversion Page....

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