1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

s4 swap, need info

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Old Jun 1, 2006 | 01:09 AM
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s4 swap, need info

how difficult will it be to swap an S4 engine into my FB? its and 85 gsl so i'll be doubling the horsepower that car is ment for. i need to know how long and around how much money not including the engine will be spent. also, will i be able to put on a 1st gen stb on it with the different engine (will the intake/ intercooler be in the way?)
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Old Jun 2, 2006 | 01:40 AM
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Most 1st gen strutbars will clear.My RB bar cleared the TII intake and TMIC easily.

Do a search,its been covered to death and asked twice a week.Thats why no one has answered yet......

The S4 is the easiest FC engine to swap since it has more in common with the GSL-SE engine.The S5 is more difficult but can be done.
Ive done both and would be happy to assist when the time comes for you to swap.Just ask specific,precise questions on the boards,and search for the general stuff like,"What parts do I need?" and "How hard is it?"......things like that.
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Old Jun 2, 2006 | 03:46 AM
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sweet, cause im thinkin of doin it myself but i really dont have anything to help with that. i dont have a cherry picker or like anything else to help me out. btw do i need different motor mounts when i put in the engine?
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Old Jun 2, 2006 | 07:59 PM
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Im doing a similar thing to my series 2 83 RX7. I recommend you opt for the series 5 instead of the series 4 motor and turbo as they is only slight differences in price and it has more potential. In the way of price it is hard to tell, you can spend as little as $5000AU or up to $20000AU on a drive in drive out deal. Im spending aroung $10,000-12,000AU on a complete rebuild high flow turbo and front mount intercooler. It will produce aroung 270-300hp at the wheels and do quarter miles on around 10pound boost in 12-13 seconds. Saw a s2 with the same setup but had been boosted to 16pound and had quality fuel running through it and slicks and it did 11.68 seconds in a quarter mile. Freakin quick

Ryan
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Old Jun 3, 2006 | 02:56 AM
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GSL-SE front cover and GSL-SE oilpan will get you mounted up.You can buy a RB 13B front mount bar,or just notch the 12A front bar.
Just rent a cherry picker,they're about 20 bucks a day and youll only need it for a few hours to drop in the block.If you have a friend,a chain, and a 4X4 post,you can install the engine by hand,the bare block is very light.

S5 is nicer,but presents a new set of issues if you wish to retain the stock EFI.Plus the S5 stuff is harder to find and usually costs more money.
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Old Jun 3, 2006 | 05:21 PM
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hmmm, i've got a lot of thinkin to do on this one. how does the s5 have more potential? now im not sure if i should keep my carbed 12a, get a turbo 12a or get the 13bt (s4 or s5)! i want to be able to drfit but still be able to grip really well for autocross and if the situation comes up ****** smoke the **** out of someone at a light. my reasons ****** ricers in my town and some ****** awesome roads to touge n drift on plus gymkhana's. ****! i need help.

Last edited by MWMburton; Jun 3, 2006 at 05:33 PM.
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Old Jun 3, 2006 | 05:42 PM
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is the 13b t going to mount straight up or am i going to need to get diff motor mounts n ****?
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Old Jun 3, 2006 | 07:41 PM
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MWMburton,
When i bought my s2 RX7 it had already been converted to a 13b carby. However my engine mounts seem pretty similar if not the same as the 12a mounts.

Ryan
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Old Jun 3, 2006 | 09:45 PM
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You dont need a 13BT to drift in a 2500lb car (not that I condone such a destructive and abusive "sport" anyways)

A bone stock 185-200 HP TII swap is more than enough to be driftable,it will probably be too much power for autoX,which is more technical and tends to be slower and more suspension/brake oriented.
As far as blowing away ricers on the street.....theres no way to know what the next car will have under the hood.It can be a Mustang or a CRX......it still might blow you away with your TII swapped FB.
Im no prude,but I just dont support street racing or the type of one-uppsmanship rivalry that "ricers" and kids seem to have these days.For all the years I spent working it up and countless dollors I spent on my turbo FB,there are still things I cant do with my car and people I cant beat...its just wasted effort to think that way.Im happy just to have a moderately powerful,reliable and unique/fun car.

For mounting the 13BT.....see my previous post...........
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Old Jun 3, 2006 | 11:04 PM
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i just wanna have some fun. i'd love to learn to drift but hate the fact it is becoming a trend. i already autocross and i am almost done building up my suspension, i have the best stuff i could find for the price and the car and all i need now is strut tower braces and sway bars to be one of the better handeling cars around. i am worried that 200 hp in my car will be too much for the autocross but i dont know anymore. i would love to have a turbo in my car and i'd love to tear **** up anywhere. but right now a performance rebuild and porting for my engine are way too much and it will probably only get me 150hp if that. (not sure about how much power porting will produce). but i dont know if i should get the s4/s5 or what. ah, im so conflicted about this. what do you think i should do? (not that i will or wont do it)
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Old Jun 4, 2006 | 12:28 AM
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If you want to do a TII engine swap,the S4 or S5 will both do the trick.I have done both to my 84 and both were massively more powerful than any N/A engine I ran in the past.The reason is torque.
Rotaries usually have to wind out to make good power.This makes them more predictable and the lower power output is well matched to the very light 1st gen chassis.And even the torquier N/A 13B engines dont have much punch,they mostly make broad,flat power across the RPM range.Predictable,managable power is what most car makers strive for in a mass produced vehicle.
A turbocharged rotary will behave just like an N/A engine when at lower RPM,smooth and tractable.But when the turbo kicks in,usually around 3000 RPM,there is suddenly a huge surge of torque and the small engine pulls like a large one.Typically,N/A rotaries dont start their big power until high in the RPMs,like 4-5K.Turbos change the way the engine delivers power,and this must be taken into account when trying to negotiate a tight quarters AutoX course,or performing acrobatic manuvers.Going from 100lbft of torque to 200lbft of torque is a huge difference in such a light car. And itll be more a Jekyle&Hyde personality since turbos always have some lag,but when they do hit its usually quickly,so you have to be prepared and basically re-learn how to control the vehicle.

Basically,the S4 is more availible and simpler to swap in because its more mechanical and similar to the 1st gen 13B of the SE.The computor is a little dumb,and they can be cantankerous,but the swap itself isnt tough.182HP and 180lbft of torque is bone stock and it can go up 30-40HP with bolt ons.I hit about 250HP with the stock ECU and controls.Supporting mods kept the whole thing alive,but I didnt like the S4's less sophisticated nature and lack of good diagnostics ability.

The S5 uses a faster computor and smoother EFI controls.It also has a superior/simpler turbo hotside and exhaust manifold.There is more electronic monitering of the engine parameters and theres a real check engine light to make diagnostics a breeze.They tend to be harder to find and cost more but J-specs are abundant and cheap.They can be a gamble and the backwards wiring harness makes it a pain to install(RHD in Japan). And there are also a couple technical barriers to overcome with the mounting and electronics of the S5's OMP,but its not an impossible task by any means.200hp and 200lbft of torque is bone stock and its capable of about 300hp with the right supporting mods and upgrades(where Im at now)
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Old Jun 4, 2006 | 02:38 AM
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thats a lot of info, thank you. that brings up a good point too. it's going to be crazy when i step on it and the turbo kicks in. i'll probably freak the **** out.
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