Help me sort out my 3.2L SC project

[Super Matty P]

I'm building a FC3S rx7 with a RWD 3.2L conversion. I plan on running a homemade supercharger system with simple bolt-ons but I'm not planning on replacing/upgrading the internals. What kind of power levels can I expect with these mods and what would you suggest for tuning. I've been reading a lot of good info about the Tweecer but I've never used one so I want to make sure someone locally will be able to help with tuning.

3.2L stock block
no PS pump
no AC system
+20 cams
Extrude honed Intake manifold w/ BBB's
Extrude honed heads
80mm MAF
190/255lph warlboro pump
larger injectors (not sure of size yet)
full custom exhaust using equal length shorty headers, catless y-pipe merged to a single 3" exhaust system

Nothing would make me happier than about 400whp on 12-15psi. Is this feasible?

 

[SASHO91]

Charge cooling and tunning... yes thats very very do-able... granted that the tranny in RWD will take more drivetrain loss, i dont see that playing a big factor..

**** even without the +20 cams, im sure 400whp is possible... granted tuning is involed...
if you havent purchased thos +20 yet, save the cash for Tweecer RT..

Im not an expert in the subject of boost.. though... im sure others will chime in.

 

[luigisho]

You might have to upgrade the FPR.

 

[SASHO91]

Yes, if he does go with the 255lph, which IMO you should...

as for injectors, im not sure what is avaliable, but IIRC 44#'ers sound right.

 

[Super Matty P]

So the cams aren't that big of a gain even on a boosted engine? I figured the additional lift and duration would be a huge gain. Cams are expensive and the work to replace is not all that fun so I may take your advice and just spend the money for the tweecer.

 

[SHOMurph]

430hp

 

[Super Matty P]

whp or bhp?!? I'll be in a 2300lb chasis so I want a little extra!

 

[Super Matty P]

Anyoen in the S.E. able to do Tweecer tuning?

 

[yamahaSHO]

So the cams aren't that big of a gain even on a boosted engine? I figured the additional lift and duration would be a huge gain. Cams are expensive and the work to replace is not all that fun so I may take your advice and just spend the money for the tweecer.

Cams will show a gain, however, you have to remember that the available cams are reground and are essentially made for NA cars meaning there is MORE overlap. With the additional overlap, you start pushing that boost and fuel right out the exhaust. With the modifications you listed 400 whp is easily attainable. In fact, with those mods at 10 PSI (and on a smaller 3.0L), I made 381 whp on 91 octane. Remember, with those intake/exhaust mods, your boost reading will be lower than what you would see on a stock motor. With that said, you'll make bigger power with a lower boost reading. I will also second that the TwEECer will be more valuable than the cams.

If you want to get the most out of the cams, your best bet is to get adjustable cam gears. I've been toying with this idea, however, they aren't needed as I'm making plenty of power and I know of a boosted SHO running stage 2 cams that is really making some good power.

44 ro 48 lbs injectors should suffice. Learning how to tune with the TwEECer will be your biggest hurdle. Putting everything together is easy, tuning the car yourself is where it is at. It's not difficult to learn. I assume you know how a motor work and essentially how injectors, MAF, ect work, right? At that poing you just have to learn the interface you're dealing with and then it become cake.

At about 15 PSI with the mods you've listed, you'd be looking at closer to 500whp if setup and tuned correctly.

 

[Super Matty P]

oh jeez. I'm going to have to make it to where I can just slide the blower belt on and off so the wife can drive the car without fear of spinning out of control.

Did I mention that the motor won't have PS or AC on it? It'll also have a new shorty header set on it with a high flow y-pipe and single 3" exhaust.


I may just start with the 3.2L motor, injectors, MAF, Tweecer, and full exhaust and see what kind of power I can make with 10,12,15psi and just go from there.

You think with 450whp in a FC3S I'll be able to hook it up?? I'm going to just order a new LSD and see how much the stock axles will hold.

 

[Super Matty P]

p.s. I just found out THE TedB. now lives about 30minutes from my house. What luck is that??

 

[ghostrider]

I'm sure HD axles can't be to expensive. They've got to have a larger aftermarket then SHOs do.

 

[Super Matty P]

well, honestly I haven't seen any but the shop thats making my subframe has said the stock NA fc axles have held over 500whp on slicks. I find this hard to believe but I don't know for sure.

 

[somedude_001]

500hp or a rotary is different than 500hp on a SHO engine. the tq if pretty close to the HP unless you go turbo then the tq is higer then the hp nd the tq is what destroys stuff.

that thing is going to rip!. have you measured the SHO engine? is it too tall for fit? i can't imagine it would be since they stick chevy 350's in those things.

the internals are really good on the SHO engine the weak point is the pistons but even then they are still pretty good. but i would replace the bearings on the bottom ends, specificaly the rod bearings because they seem to wear a bit fast. simple and cheap no biggy.

 

[Super Matty P]

I agree. The engine I got was babied and well maintained. I'm hoping it won't need anything more than I what I mentioned adding.


Yeah, there's plenty of room. The company building the subframe frequently puts 351's in these cars so I should be ok.

 

[Off Road SHO]

Yeah, there's plenty of room. The company building the subframe frequently puts 351's in these cars so I should be ok.

I think our engines are bigger than a 351 due to the verhead cams and the intake system. I think I have a Windsor out back; I'll try and get some measuements.

Tom

 

[Super Matty P]

Tom ,I think you're right. In hindsight the 351's I saw in the chasis had cutouts in the hood. I wish someone had access to a standard 5.0 so I can measure the hieght from oil pan to IM.

Maybe the motormounts can be made to actually lower the engine in the bay. The u-joints on the driveshaft should be able to handle an extra inch or so of travel.

 

[Off Road SHO]

Lowering is always an option as long as you remember that you did when rolling across speed bumps.:laugh_ti:

I always thought that a really cool look on a SHO powered vehicle's hood would be to match the outline of the snakes. I know it would be difficult **** stain to do, but it would sure get the attention at car shows.

Tom

 

[Super Matty P]

good lord that would be expensive!! Just a stock replacement CF hood cost me $750. I couldn't imagine what a custom molded hood would run. Also think about how the engine would vibrate side to side. Would it ever coem in contact with the hood?

 

[Off Road SHO]

Who said it was going to be cheap? All of my ideas are expensive; that's why not many turn into projects.:laugh_ti:

Tom