My goal is to stay on the stock twins yet reach the highest hp rating that I can.

In threads I've seen that most stock twins can reach 350hp (how much psi?) and I'm trying to figure out what else I'll need to achieve this. I have the following mods already.

Greddy Intakes
PFS Intercooler
HKS Mild Steel DP
RX7Trix MP
Racing Beat Dual Tip Exhaust
RPS Performance clutch (street disc with a sport pressure plate)
Unorthodox Racing Underdrive Pulleys, anodized blue
M2 Radiator
Aluminum AST
Greddy Profec B spec II (turned off right now until I install MP/PFC - 7psi)
Greddy Turbo Timer
Fan switch mod
Power FC (base map)

I'm guessing the next thing I'll need to upgrade is my fuel system? What else after fuel? I'm looking to buy another BOV pretty soon. I had an HKS SSQV but it broke so I'm on stock BOV right now.

Last but not least would of course be dyno run/tune.

 

I'd say you're already practically there, it's very important to port the turbos wastegates before you install a midpipe to avoid boost creep, but other than that you should get your secondary injectors reflowed to 1300cc, primarys flow checked and get a supra tt/nippondenso fuel pump. Then it should just be up to boost and tuning, the general consensus is that you can't run over 15psi unless you have auxiliary injection or run race gas but I think 14 or 15psi can do it. It would also be useful to have a nice set of gauges to diagnose any problems before they become catastrophic... And with regards to blow off valves I havn't needed to research those but I'd think with the greater boost the stock bypass valves might be overwhelmed so installing one could also be a good idea. Good luck.

-Andy

 

Porting wastegate is one of the things I will be doing. I remember a thread a while back of one of the bay area guys around here taking his turbos off and porting it himself so possibly I can find him and maybe he'll help me out. He has a step by step somewhere on the threads here.

What do you mean by get my secondary injectors reflowed to 1300cc? You mean just buy 1300cc injectors or what is meant by "reflowed"? Supra tt fuel pump was found for ~$80 so I will probably pick up one of those and should be a direct replacement/bolt on from stock correct?

 

i'd do a custom intake so you don't suck in hot air from behind the radiator. that'll help out a bit.

 

Pic of engine bay

 

cleanliness is next to godliness

very nice looking! i don't dig the smic... they heat soak WAY too bad on dyno's, but a very nice setup, nonetheless.

 

I hear the previous owner was really **** with the car

Brian, get an efini y-pipe, midpipe (I'd recommend a high flow catalytic instead), port the waste gate, upgraded fuel pump, larger injectors, good tune @ 15 psi, and you're good to go.

 

Hah, well the previous owner sold his car to another **** person who washes the car almost every week and whenever he sees a spot on the car has to drive home to wash it off lol.

Anyways, I already bought the midpipe with the PFC (combo deal). I'm looking to port the waste gate hopefully sometime this coming week. Found a supra tt fuel pump for $80 and then larger injectors/y-pipe will be later on into the year as right now I'm pretty short on funds and need to save to buy xmas presents.

 

Without the injectors you'll want to run 12.5 psi and under, because you'll be hitting some high duty cycles.

 

+1 for what everyone said above.. midpipe, more fuel, port WG.. And good tune.Good luck. G

 

upgrade your fuel system!!!! ask me how I know, 13-15 psi on stock fuel sys= popped my motor.


oh and very very clean car. looks nice

 

There are thousands of people who have run those boost levels on the stock fuel system on these cars, without problems. Heck they were doing it LONG before most people here owned or knew about these cars. There is more to running more power on these cars than just fuel (i.e. charge temps, ignition, etc).


HardHitter,

Are you looking for around 350rwhp? If so, not too many cars make it there on stock ports using the stock twins and the stock fuel system. With the stock fuel system, you can get there on 15 PSI (which you can do on the stock fuel system, and its been proven) but you need a ported engine to do so. Without a ported engine, you'll most likely need to run higher boost, therefor requiring more fuel. I believe you can get close to that number at 15 PSI. Heck, maybe with some Steve Kan magic dust, you can get there but at 15 PSI but its not likely without engine porting.

 

http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

Thank you Max Cooper..

 

Mahjik has the right of it. A ported engine would go a long way alone towards your goals, but obviously you are trying to get there with 'external' mods before you consider tearing the engine apart and doing more work that way.

I guess I have to ask, "why?". Your car is sweet, already makes some good reliable HP.
When is enough, enough?

 

Here is a pic of my engine in the sig. I have a pettit intake, M2 med. w/ a pull fan and 1600 cc secondary and of course an upgraded fuel pump. I run 13-14 psi boost and seeing 350+ rwhp on 93 octane. But of course the engine is ported.

 

Hope you're not chasing big numbers just for bragging rights... Longevity is more important unless you have nothing better to do with your money.

I've dyno'ed 350rwhp with a ported motor, fuel pump, 1300cc injectors and all supporting mods. Tuning makes the biggest difference. I normally run the car at 10psi on the street so at around 300 or so.

 

Quit worrying about hitting a number. I know how you drive your car and the fact that you are in college. These facts equal = don't push it.

On our ****-water 91 octane, you can run 15 psi with an upgraded fuel system and safe tune. With a safe tune, you would probably make around 340 rwhp on your stock-ported motor. Don't push it just to make a few more hp. It's dumb and not worth it.

 

Dont mean to go off topic....but is there any way to avoid boost creep when installing a midpipe besides having to port the wastegate??

 

Install and watch your boost gauge... no, not really.

 

Not going for bragging rights just thought I'd mod the car a little. Not going to port the engine or anything like that just for extra HP until the time comes (hopefully no time soon)

Just looking to have a nice reliable daily driver with some good power for my own fun.

 

You can take out your injectors and ship them to shops that will upgrade them from 850cc to 1300cc. Some other good points were brought up, ported motor and 3mm seals etc, always help. And the ultimate would be a turbo upgrade such as the BNRs . Also I don't think it would be an issue but if you have problems with ignition break up you should invest in an HKS Twin Power.

-Andy

 

Actually he can have a restrictor plate made and have that mounted somewhere in the exhaust.

 

what's the point of removing your emissions gear to replace it with a plate that does the same thing as far as flow is concerned yet doesn't do anything for emissions.

might as well just put the cat back on.

 

Nice car, goodluck to 350.

 

Using a 1/8" piece of metal verses 12-14" of restriction are two completely different things. The restrictor plate just adds enough turbulance for the boost to be controllable. That's it. Its still a signifigant gain over using a converter.