tuckerchef

So I've got an opportunity to get my car on a track in 3 weeks. The only thing is all the other cars are vipers and corvettes oh there is one miata and a mitsu eclipse.

I want to squeeze more power out of my 1990 rx7 j-spec. Current performance mods are as follow, 3 inch no cat exhaust, intake is done, HKS BOV.

Even 50 more HP would be nice. I'm new to the turbo scene. Can I achieve this with a boost controller, new fuel pump and injectors? Help, fast. I at least want to cream the mitsu.

Suggestions,,,, $1500 budget. bolt on only please. Thanks for any input.

tuckerchef

Guess I should mention my car is a turbo II FC3S

RXSpeed16

iTrader: (41)

Couple questions: What boost are you seeing now? Are you hitting boost cut?

Upgraded fuel pump (Walbro 255, Denso Supra pump, FD RX7, etc), fuel pump rewire, Fuel Cut Defenser, ported turbo wastegate + boost controller set to 10 lbs max should net you about 20~25 at the wheels.
Above + 720cc secondary injectors, boost controller at 12 lbs., Rtek 1.7 ecu upgrade should net ~40 @ wheels.
Too much boost and not enough fuel is what kills the rotary engines, so make sure you have the fuel mods taken car of first.

A set of springs and shocks will do wonders to improve handling over the worn out stockers, too.

I'd warn against upgrading in a rush like this, as it hardly ever turns out perfect. The injector install is also a bit more involved than other vehicles due to their location between the upper and lower intake manifold. Just saying it's not really a typical 'bolt-on' installation.

Overall, if you are new to the car, I'd just take it as is and try to hang with the miata in corners. Afterwards, decide what you want to tackle (power, suspension, tires, etc.) Have fun and good to see another car being taken to the track.

tuckerchef

I've already upgraded the suspension, sway bars, volk racing rims, and tires. I'm just looking for a little more from the engine. I'm only running stock boost. Haven't seen boost cut yet.

What can I do just to get a little more from the stock turbo? The danm boost gague is in metric. and it only tops out at 0.5 KG/cm2 so that's 8.1 psi

Can a boost controller alone get a little more boost without a fuel upgrade and a ecu upgrade?

RotaryRocket88

iTrader: (7)

If you want the engine to blow halfway through the race, you can slap a boost controller on there & use a Racingbeat FCD to prevent fuel cut at 8.6psi. Would I suggest doing this? Hell no.

At the minimum you need a better fuel pump and something like the Rtek chipped ECUs to properly prevent fuel cut. FCDs are utter crap, since they alter the boost signal to the ECU. Screwing with that signal interferes with fuel delivery and timing retard under high boost. Modify the engine correctly, and don't get overly boost happy. You'll be the slowest car out there if you lose a rotor and have to side-line it.

tuckerchef

Thanks guys, great advice. I just got the car and want to have some fun with it this summer, I'm planning a big build for the car come fall when I have more time.

Thanks again.

RXSpeed16

iTrader: (41)

Good choice! It's nice to have someone actually take the advice they ask for. Enjoy the car and welcome to the forum!

Tessai76086

iTrader: (3)

I HIGHLY recommend the Rtek 1.8. However to do so you will need a full set of injectors (4) 750cc or larger. Walbro or other fuel pump and a fuel pressure reg. Well, I say a FPR but yours may be able to take it. Mine sure couldent. After that I would go with a boost controller. Make sure of course that all your filters (air/fuel) are clean and ready for the track.