ReFc

iTrader: (3)

well ill start with my mods

cold air.
no emissions.
tb mod.
rf320 knight sports turbo.
strait through 3 inch custom magniflow exhaust.


Ill start with the easy. I did the tb mod a year ago or so when i didn't drive the car daily and the car idles around 2k to 2,3k which is now a problem for me because i need the car as my daily transport and the idle is not gonna work well in traffic. Is there any way to lower the idle any more with the tb mod?

next

I think i have a boost leak somewhere but im not too sure. Only seems to happen at 1/2 throttle and at wot. feels like the car looses all power and starts bucking. Ive had this problem since i put the t2 swap in with all the stock parts and still cant figure it out. I have the pill for the map sensor so there are no spikes there.
On the new rf320 i installed i just looped a vac hose from the turbo to the actuator. I didn't want to use my manual boost controller until i found the problem. Ive checked the map, afm , tps with a multimeter and they are all in range and work properly through ranges " no drops no spikes ". The bov does release some pressure when decelerating.

does this sounds like boost leak or fuel problem??

RotaryRocket88

iTrader: (7)

The TB mod doesn't raise idle speed. You must have bumped the throttle stop. Adjust it until the car idles where you want it to.

The other problem is bound to be fuel cut at 8.6psi due to boost creeping. An open intake and exhaust will do that if the wastegate is not ported.

Also, I hope you have larger fuel injectors, a better fuel pump and some sort of fuel/timing control to go with that turbo. Otherwise, at higher than stock boost levels, you will blow the engine.

jmabo205

iTrader: (1)

+1 you need some way to control the boost, ecu, boost controller, etc. with a bigger turbo 3inch exhaust with no back pressure, your going to blow the engine. the stock secondary injectors won't cut it safely, your probably using them a 100% capacity and could fail and leak. Do what rotaryrocket said and readjust your throttle for idle.

ReFc

iTrader: (3)

well im about to rtek chip the ecu and go with some 720's , ???? and as for the boost control, i don't really trust manual controllers so what should i go with?

oh and i was wrong about the exhaust its 2.75'' strait through
not a big diff but still pretty open.

any other suggestions on what else i should do on this would be appreciated :]

vrracing

iTrader: (1)

When we built the Tii we put in the vert we saw a similar bucking in the 3-4k range. Stock turbo, RP downpipe, Bonez cat, Corksport exhaust. Pineapple porting. Stock intake. Have an RTek1.8 with 720 GReddys and 1000 RCs. Also a Zeitronix w/b and boost.

We used an SAFC to richen it up from 3-4k as that was causing the bucking. It was really obvious on the Zeitronix graphs. Once we got the AFRs in the right place, it smoothed right out. Since you've done all those airflow mods without compensating for it with any mixture control, I'd guess you're seeing the same thing.

jmabo205

iTrader: (1)

for a boost controller i would say that greddy profec 2 is good, thats what i use. But if you want to really good one and have the money i would get the apexi avc-r. That one is really good, but kinda hard to get use too, but imo is probably the best.

For the injectors the size depends on how much hp you want. If your looking at just 300hp, 720 secondary is good, but if you want more than that i would get at least 1000cc just to be on the safe side. with that you will need a better fuel pump like walbro or the supra tt pump, and a better fuel pressure regulator.

jmabo205

iTrader: (1)

also, vrracing could be right about your problem, you could be running lean in higher rpm, check the voltage from the fuel pump and see if its good, if not rewire the fuel pump.

ReFc

iTrader: (3)

ok rotaryrocket was right about the throttle stop. idle is fixed.

i did the rewire a few years back and did put a high flow pump that was making about 50-65 pounds of pressure... i switched the wiring back to stock but i still have the harness in the car for the rewire. i forgot why i did?

i did forget to mention that my gas tank is rather rusty inside and the filter on the pump gets a little muddy sometimes. i have a brand new borg warner fuel pump somewhere. what kind of flow are we looking for in this setup? at least something close to the 255lph that walbro pumps put out? also this is a t2 s5 swap on a n/a chassis... are the steel fuel lines on the chassis the same size as the lines on the t2 chassis?

ReFc

iTrader: (3)

ok a little update.

i rewired the fuel pump again and it showed some improvement. there is no problem geting a little boost going now. i made about 3 psi by 4k. there is still a boost leak somewhere and i found a leak where the exhaust and the turbo mate.

i went ahead and pulled the fuel pump and found it was an airtex replacement which pushes around 60 gph or 227 lph which is prob not enough for my setup.

still workin on it....

ReFc

iTrader: (3)

bumpo

ReFc

iTrader: (3)

about the rtek7.

since the S5 TII is only in stage one for rtek i would have no control over maps or timing and would only be limited to the injectors size pre-programed to the chip. so its a little pointless to go that direction? it does have timing retard at boost and all. then i could use safc to fix maps?

RotaryRocket88

iTrader: (7)

Yes, you can use an AFC to increase fuel delivery in the mid to upper RPM range. The Rtek will make your job easier, and make it so you have to "fool" the ECU less. When you tweak fuel with an AFC, it also inadvertently causes change in the timing. The boost based timing adjustments on the Rtek will help in this area, as well.

You also should be using at least 4x 720cc injectors with that turbo. In order to use it to it's full potential ( up around 15 psi or so), you'll max out a 550/720cc combo. Having some injector headroom is a good thing, since maxed injectors can stick and blow an engine.

ReFc

iTrader: (3)

thanks alot rotaryrocket

i found a set here for sale, how would 750's do on the secondary rail? would it run just a little richer?

RotaryRocket88

iTrader: (7)

Just a bit richer (4% more fuel), and you could adjust that out with an AFC.

ReFc

iTrader: (3)

in your opinion what version of the safc controller works the best?

RotaryRocket88

iTrader: (7)

No idea, I don't use any of them. The Apexi SAFC is probably the most common.

ReFc

iTrader: (3)

well...

i wish we knew the eta on the ver.2 rtek. i wouldnt have to worry about gettin a piggy back.

do u think it would be necessary to get the safc if i keep it at stock boost levels untill i can get my hands on the new rtek chip when it comes out?

vrracing

iTrader: (1)

No. You still have to manage the air fuel ratio. We are still running with the stock boost (5.5?) and had stuttering when it'd lean out in the 3-4k range.

Remember that an engine is a big air pump. With your mods, you've made it a more efficient air pump. But the ECU, even an RTek'd one, doesnt know that so it is still squirting fuel as it you had an unmodded system or one that matches the RTek's assumptions about what has been modded.

Putting bigger injectors on is a guess. And the injectors are a fixed change across the RPM range (ie, they are 4% more across the board) but what we found is that the mixture will change across the RPM range (I'm guessing because of fluid dynamics that are too complicated for me to figure out). We put an RTek1.8 (rated for 720,720) on the S5 Tii we built with 720,1000s and still ended up with a big lean spot in the 3-4k rpm range. I expected us to be stupid rich above 3400 when the secondaries kicked in. We weren't.

IMHO based on my experience building our Tii Vert, on the board there should be a big sticky in all caps saying "DO NOT MODIFY YOUR ENGINE, INTAKE OR EXHAUST WITHOUT A WIDEBAND AFR SENSOR!"

Even with an SAFC, you'll still need to see the wideband AFRs (reading off your stock oxygen is a waste of time and money) so you can tune the SAFC. I have a Zeitronix one but there are several others.

Note that the cost of guessing wrong on the AFR on a rotary is likely a rebuild. You run too lean, you detonate. You detonate, you break a seal. You break a seal, you cry.

Good luck!

RotaryRocket88

iTrader: (7)

^ The Rtek base fuel maps (which is all the stage 1s have) are 90% stock. The only thing that changes is a 5% increase before the secondary transition, which is moved to either 3500 or 3600 RPM. All of the other points in the map are adjusted ~ -25% to allow the same flow through the 720cc injectors as was available with the stock 550s. This is part of why a stage 1 alone should not be the only engine control used with anything other than the stock turbo. The change in air flow characteristics doesn't have to be huge to throw off the AFRs.

The second part is the stock timing, which is pretty aggressive even with the added boost-based retard over 9psi. I'd imagine you could drown the engine in some extra fuel in the upper RPM range to try to compensate for this, but it's not the most ideal situation. But this factor could also be lessened if lower boost is used. At stock-like boost a small hyrbid should have top-end airflow similar to the stock turbo. But that doesn't mean the fuel should be ignored just because boost is at stock levels.

ReFc

iTrader: (3)

yea im about 1k deep in stuff i need to buy

thanks for all the insight rotaryrocket! vrracing!

vrracing

iTrader: (1)

$1k? You have not yet begun to spend!

ReFc

iTrader: (3)

whoah i just noticed something...

why is my oil pressure showing 0 at idle!?

and a little above 30 at 3800 rpm?

eeeeeek!

ReFc

iTrader: (3)

eh... lol
false alarm...
p-o-s sending units ftw

here's the thing that really stumps me about all this that we have been talking about...

vr u said that you had to richen your range up a little to keep it from leaning out....

i swear i could kill myself if i lit a match in my garage! the damn thing smells so rich! even at idle! almost seems like the primary's are running at 100% duty.

oh and on top of that i was tweakin around with vac hoses and accidentally unplugged the map sensor... but nothing really happened? need to check the map sensor again i guess...

vrracing

iTrader: (1)

I think cars of this gen smell richer than newer ones. We have a 91 MR2 turbo, the 90 RXVert Tii and my 04 G35 coupe. The two older ones smell richer than the G.

but if you smell gas I'd check that out in a hurry. We had a misty leak from the fuel line from the filter to the hardline that was hard to see but really dangerous.

I'm convinced that without a w/b sensor it's really hard to judge mixture by smell. But maybe that's just me.

btw, how do you know your low oil pressure is the sender?

ReFc

iTrader: (3)

yea well it kinda slipped my mind Ive seen it before where the gauge would read zero at idle. im gonna hook up mechanical gauge and try to read the true pressure. i mean if it really was zero the car wouldn't run at all lol.

im lookin at AEM's UEGO w/b controller. looks nice but wth do i know about w/b ha.

prob just save up for the zeitronix setup...