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-   -   need help with engine decision? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/need-help-engine-decision-128242/)

80CID 10-29-02 08:04 PM

need help with engine decision?
 
Ok, I’ve been throwing around a bunch of different engine ideas and I can’t seem to decide what would work the best on my budget.

My car is a 1988 turbo that I plan to Auto-X and then slowly move into IT (improved touring). I’ve pretty much got all the suspension and braking items taken care of, so now I need an engine. One more thing I will not be driving this car on the street.

1st idea- Turbo motor with a 60-1 hybrid turbo and an FMIC with a Haltech, this will be very expensive because of all the turbo and electronic components.

2nd idea- An all alum. LS1 or an iron block LT-1 Corvette engine and 6-speed trans., this will also be vary expensive about the same price as my 1st idea, but I think it would be more reliable with the same HP in the long run, but it would also add more weight and it would raise the center of gravity. This can be done but.....

3rd idea- A bridge ported N/A I think that this would be the least expensive route but I don’t know? What kind of horsepower can you get from an N/A? I really like this idea but I need some more info.

What engine should I use Turbo or N/A? I thought that the Turbo would be better to port.
Can I use the turbo oil cooler?
What about carburetors and intake? (Webber Carbs.)
What about the distributor? Can I use a distributor from an 12a?
What about the fuel pump? Can I use the stock pump and regulate the pressure down?
If im not using fuel injection will I need to run a computer like the Haltech?
What about a header, will a N/A header fit a Turbo Engine?

This is the idea that I like the best as long as I can get some good HP numbers.

Sorry about the long post. Please help or direct me to a web site that could help me.

-Bill

80CID 10-29-02 09:39 PM

can't anyone give me some options? or opinions?

-Bill

Rs4Racer 10-29-02 09:49 PM

You can make somewhere around 250hp with a bridge ported motor n/a.

the aluminum ls1 wont add weight over a stock tII setup, and you will have gobs of torque and power. If I had already been thru a turbo rotary and wanted to experiment around Id put a ls1 in my car. Theres alot of custom stuff you have to do I think but theres been alot of it done so lots of support. Theres a guy named thewrongmotor I think thats his name look up his name and youll find more info.

A turbo would be cool but I think you have to keep the weight stock witch sucks....

Silkworm knows alot about racing you should ask him.

I hope he doesnt mind but here is his page its awsome it shows alot of steps on building the racecar. truly inspiring ;)
http://www.lcaf.com/silk/RX-7/rx-7.html

LT1-10AE 10-29-02 10:04 PM

With the options you've expressed, I would go with either a ported NA, or the V8 swap. The V8 swap will probably stick you in your own class. The 60-1 turbo setup wouldn't be good for auto-x unless you've got some REALLY long straights. In order to stay in a class with others, the NA route would be the best. I'm pretty sure you can get the car into CSP if you let the tech inspector know it's not a turbo.

The NA will be great down low and awesome up top with a decent port. The V8 will be a grunt machine that will become a "steering defeat unit" if you're making tons of torque :)
The turbo will probably just start to spool (if at all) by the time you're on the binders headed for a turn.

A lot of auto-x courses I've seen are very tight and relatively short - you'll probably never get into 3rd gear. 3rd gear with a 60-1 is just plain magic :D

As far as fuel, the stock NA fuel system should be fine for the track. EFI on a rotary is a lot easier to keep running correctly than a carb'd setup.

chris-reedtn 10-30-02 12:42 AM

call me crazy but whats wrong with the turbo motor the car came with? why wouldn't you use that? That motor, rebuilt, ported, exhaust, s5 hybrid, or just stock turbo, with full exhaust and intake. Should make good power and be fast off the line and if you have a good suspension set up fast in the turns and fast in the straitaways, and this all coming at minumum cost.

1200 rebuilt ported turbo motor,
500 Exhaust,
40 intake
250 turbo
100 fuel pump,

THis all much cheaper and alot better combo to me,
With good auto X power and handling, while still sticking to the motor that the car was designed and built for.

Prepare for flames on here if you go with a domestic V8 your handling will be impared sugnificantly. when you floor it coming out of a turn the torque will cause the tires just to burn, Your cost for this swap will not be cheap by anymeans,

But its all up to you,
just my .02

-Chris

Rotorific 10-30-02 12:54 AM

I would go with the turbo rotary setup theres nothing like it dont take the life out of a rotary by fitting some fatass v8 in it....

Rs4Racer 10-30-02 01:38 AM

With the v8 the overall weight comes out the same as a stock tII so how would it affect handling?


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