RussTypeS

iTrader: (3)

so the GRM $2004 s4 FC is still being stripped. im tying to figure out how to get some cheap power and what the bottlenecks are in the stock system. so i can get some parts in to make it go fast.

its fairly obvious i can just turn up the boost, but what limits how far i can crank it? turbo? injectors? fuel pump? ecu? what are the limits of the stock components and in what order should i upgrade to get the most out of the engine with the available $$?

i was thinking of starting with the walbro fuel pump and fuel pressure regulator to bump up the fuel pressure, which will hopefully keep me from having to get larger injectors. then do an FCD to keep the ECU happy, but would i then need an AFC to keep fuel in check at higher boost levels? whats the limit of the stock turbo?

i also found that my pulse damper screw has fallen out and i hear thats a sign that it is not good. can i just remove the damper and put a bolt in its place or will that kill my fuel pump? i havent found much info about it on the forum but have had people tell me they have done it with no ill effects...

dubulup

https://www.rx7club.com/forum/showth...hreadid=224479

they talk about eliminating the FPD...and the effects on injectors.


I would say the biggest bottleneck in turning up the boost would have to be fuel...you have to have enough fuel for added boost (and something to control the injectors, maybe a piggyback would be cheaper than buying a stand alone or chipped ECU. What is FCD???). Then maybe the turbo, it can't be blasting extremely HOT air into your motor...I don't know what the limits on the stock turbo is. cheap way to limit or turn up boost, could be a ball and spring valve to control the wastegate venting.

Might not be a need for new fuel pump and regulator if you don't want to change the injectors??? Just max out the injectors and that should be achievable with the stock set-up. What injectors are in the car? Isn't this a NA-T swap project car? I have a walbro I can sell you...(bought it from forum (low miles) haven't had the need for it yet) pm me.

https://www.rx7club.com/forum/showth...ater+injection

great info on WI. You can build the kit for under $200. And will allow you to run a few more pounds of boost (if you have the fuel)...I believe an IC sprayer could be added to the set-up pretty cheap too.

Just my opinions...

redrotorR1

The CHEAPEST way to add power ... spray it. I think most of the FB's and FC's in last year GRM challenge were using nitrous.

eoph

if you turn up boost, i'm pretty sure a fuel pump would be wise

RussTypeS

iTrader: (3)

thanks for the link to the thread, since i will most likely buy a FPR i may get one that performs the same damping function and remove the FPD.

FCD=fuel cut defense, to trick the ecu into thinking i am only running 8 psi so it does not cut fuel to the engine.

the car has a fairly complete TII swap, the injectors are (i think) the stock 550's. im not really sure how to tell what i have yet. water injection scares me, but im planning on running the stock windshield washer squirters to mist the intercooler.

im going to spray if i have money left over, but i would like to have the power at the autox as well.

so can i get up to 15psi on the stock injectors with an upgraded fuel pump and higher fuel pressure?

dubulup

Don't be afraid of WI and that sounds like it can be done

ZeroBanger

There is no reason to be scared of water injection. at first you think....that your spraying water in your engine and that has to be bad. But if you saw what I saw..experience what I did..you would change your mind. Have you ever been to the grocery store and in the produce section so see a fine mist of water spray? its like that except even more fine. When i take my elbow off just for kicks and giggles and run this...I put my hand in the elbow to feel the mist in the air..its so fine that alot of it evaporates even in the ambient air.

Under boost conditions 75 pct of the water will evaporate, what doesn't will go into the engine, clean it and further prevent detonation. You will know if its too much water, your car will hesitate and you will notice a power loss. In that case, either add alcohol to your mixture or replace the nozzle with a smaller GPH unit.

Having said all of that, when I first installed this I did not have a LED indicator (big mistake). I had a short and my water pump was activated anytime the car was started. It was running with a big 7.7 GPH nozzle in my elbow for more than 40 minutes. MOst of the time was just cruising on the highway. It took almost 40 minutes for my car to tell me something was wrong. I car started hestitating. I realized the water pump was on and unplugged the wire.

Even through all of that my car didn't hydrolock. Since then I have taken an effort to really check my installation and its been running great. I wouldn't be without it, driving around with 75F intake temps on a 105F day is pretty cool. Also, the way the car feels on a hot day is like what it feels like at night.

Just do some research to see if its for you.

Project84

the cheapest way to get power is weight reduction. Its not really adding power, but the less weight that has to be moved, the more power there will be available to the rear wheels.

damaged-g00ds

in my pexperience the quickest what to get power with a turbo charged car is , upping the boost, now everyone knows when u up the boost you need to up your fuel, and this isn't very cheap and the thing here is cheap HP, so my solution to this is "methanol" all you need is like 1 0r 2 injectors a pump and little 5litre tank or so and a hobswitch. now you set the methanol injection to come in only once you go past a certain amount of boost this way, you can still cruise around normal and now use any of your precious go go juice hehe, with a good methanol setup you can run 19psi EASILY we go some guys running here with 20psi as a daily setup just dont run out of methanol because u cant hear detonation over 15psi and then everything goes boom boom, hehe i know 3 pistons later hehe, not sure if it effects a rotary the same but i know its BAD!!!! hehe yeah so anyways think of the hp with 19psi - 24 psi boost WHEEEEEE!

RussTypeS

iTrader: (3)

ok well i may try WI, methanol might be worth it as well, but keep in mind that iwill prolly only have about $500 to spend on power adders after spending the $$ to get the car to run and the suspension. for sure something to look into, but a tank for methanol, pump, injectors, regulator, electronics to control the methanol, sounds like $$ to me.

obviously weight reduction is key. not only will it give better acceleration but better handling and braking as well. believe me i am a huge advocate of weight reduction and its my primary focus with the car. weight reduction is also free (well, free until it starts to get extremely expensive), so i have some money to spend on getting more power. the car is going on an extreme diet, and will most likely be under 2400 lbs (under 2300 lbs if i decide to remove the bumpers).

damaged-g00ds

yeah weight reduction is the most inexpensive way to get increased performance hehe, but the meth kit is not actually that expensive, obviously u can do it a cheap way(in the long run will be more expensive cause you spray in into your turbos and it kindoff eat away your compressor wheel hehe, so not good idea) and then you have the right way of doing it where you inject it in to the intake manifold, obviously abit more expensive, but a nice kit, will prolly set u back like $300 (thats converted, and without the meth hehe) i think meth is like 9$ a gallon in the states, its much cheaper here although a new turbo here is like $200 dollars so like yeah its hard to judge with the currencies n ****, then again $200 is a lot of money here so yeah hehe its all much of a muchness, but when i get my fd i am gonna meth it to the max cause the octane rating is so low in the rest of the world hehe our regular fuel here is 97 octane, which from what i know is high and then we can buy cans of 102.6 octance from the gas stations so yeah hehe its all good! hehe

David Kim

this is what i did to my friends FC, cut off inner apron, remove impact bar w/ absorver, cut off some part of radiater(not upper tiebar), added fiberglass fender, cut off front door inter shell n removed side impact bar, cut off passenger side floor n added fiberglass piece, cut off inter quarter panel, n as usual remove trims.

chairchild

No-one's mentioned the obvious - exhaust and air filter.

i know it's not even worth mentioning, but Iwanted to post something!