RB25 s14 very slow...please help

[bovaddict]

Hello,

I dont usually post up things like this, but everything that I am finding from searching has not helped, yet. I really appreciate it if you read through all my over explaining and have any ideas!

I have a rb25det S2 into a 95 s14. no hvac/stereo etc, wiring specialities harnesses with stock chassis harness, stock rb25 s2 ecu, no solenoid(read online to plug that in, but I dont see any spot on my harness for it?) also have my AAC valve capped if that matters

fmic, 3" turbo back, turbosmart raceport bov, walbro, aeromotive afpr set @42-44psi, mishi rad, other misc mods. fresh oil change, fresh plugs, coolant etc(swapped over winter)

I drove it around without giving her over 1/2 throttle and seemed fine, would boost and hold it and sounded great and had enough power for daily driving that I didnt need to give her really any more power while making sure it was safe.. well after about 120 miles of just casual driving over a couple days to make sure it ran great etc, I decided to floor it.. to my suprise, this car seems slower then my n/a daily forester with bolt ons...maybe just as fast at best? but it sure does sound better!!!

Anyway, it went smoothly through the revs with no feeling of being put in my seat even downhill, doesnt sputter or bog, doesnt sound lke a boost leak or sound like its having any issues at all at any time driving it..but its not fun in the least, I would get walked by the wifes 4cyl newer accord guaranteed.. this sucks

So in case you didnt read earlier, Im not running the boost solenoid, explaining the 5psi cap, but I dont have a place on my harness to plug in the solenoid?

I have a manual boost controller I can install if that will help.

I also have a mines ECU that I purchased on here months ago that is tuned for the same mods as I have.. will installing that help?

I havnt tried them myself because I am afraid it could be making a simple problem, into a bigger one.. if that is not the case, then I am all for it as I am tired of having such a slow "track built" car

Thank you!

[ultimateirving]

Sounds like timing? but also, 5psi is bad, put that MBC on there and crank it to stock PSI.
(which for an rb25 is????? I have no idea sorry)

[twofouroh]

Check timing, 7psi is stock boost also diag your ecu for codes, i found out the instructions on some old forums through google..

[fliprayzin240sx]

Check base line timing, TPS voltage, what sparkplugs/gap, make a boost leak tester and look for leaks.

[bovaddict]

update: did a boost leak test and found one.. solved it and went for a test drive right now and it just bogged as soon as I gave it gas. It does not want to drive.. It then felt like it was missing or something then would want to take off but I didnt want to let it..

Any ideas?

[bovaddict]

and it ran 100% smoothly but no power before this^^

[ultimateirving]

Boost leak still, u forgot to hook something back up

Also check some of the other things Flip mentioned.
These can all be impacting your motor and causing it to run slow

[bovaddict]

Maf wasn't hooked up... Damn I'm dumb

[bovaddict]

Ill drive it tomorrow and I assume the Maf being plugged in will help. I'm going to reset the Ecu and install the mbc and ill post what the result is

[mantas]

Stock rb25 is slow even if running correctly. You really need a tune to get the full potential. At 9psi its ok but nothing special and anything above 9psi hits a wall because the stock ecu pulls timing or does something else to prevent it from blowing up. Lol

[feito]

^goes into rich and retard. Check your plug gaps, try them as low as .023 and double make sure u dont have any boost leaks. Also u'll need a wideband

[bovaddict]

I have a mines Ecu going in whenever this snow/rain stops... Also the mbc and my plugs are gapped properly according to whatever spec I was told for the mines Ecu to prevent it from blowing out the spark or whatever.

Ill post results when it's nice enough to drive again, thanks again!

[bovaddict]

Reset the stock Ecu, didn't add the mbc, and went for a drive.. Slightly wet out but there is 0 traction to be had and she pulls much harder!!

Ill have an actual update when it's dry again..

[mantas]

Reset the stock Ecu, didn't add the mbc, and went for a drive.. Slightly wet out but there is 0 traction to be had and she pulls much harder!!

Ill have an actual update when it's dry again..

Yeah the torque doesnt help at all in the rain. If its raining out i can literally spin my tires all the through 4th (never tried in 5th) but in the dry it only spins first lol. And even then its only when the weather is colder and the engine can breathe easier lol. The stock ecu is just garbage from what i hear, just changing over to different ecu and doing a minor tune on the stock engine it will come alive.

[bovaddict]

Well I'll toss in the mines Ecu and mbc and see what happens then :) once work is done I gotta see how it does on the dry (275 toyo t1r's, welded diff)

[bovaddict]

Rain and more rain, snow

[mantas]

Is that the forecast where you live? Well its 95-100 in cali today and it aint fun lol.

[feito]

bs, i understand stock rb25 ecu's r crap but i wouldnt consider it slow by any means. i recently got my rb on stock ecu running flawless and decided to hit the strip for the first time, my very first time and managed to run 14.1, my rear end would keep bouncing during during launch and i was running on street tires, re11's. Give me a few more trips to the track, hell maybe even just a few runs and i'll be in the 13's. So with a good driver i'd say it can run mid 13's. The thing is the stock ecu is very picky and most guys dont pay attention to details. Running right, even on stock ecu, rb25's r fun as hell for the beginner.

[mantas]

Lmao. It might be kinda quick at the strip etc, but not fast enough for me. Like i said, in stock form the rb25 is ok but once you throw in a management system - hold on to your pants!!! Mine has lightweight driveshaft, flywheel, 9psi, neo turbo, ls7 coils, exhaust, ic, q45 tb, freddy mani, few other things. Either way, with each upgrade i noticed a slight increase in power but nothing can match what a tune will do. Hopefully i can get it done soon....

[feito]

Lmao. It might be kinda quick at the strip etc, but not fast enough for me. Like i said, in stock form the rb25 is ok but once you throw in a management system - hold on to your pants!!! Mine has lightweight driveshaft, flywheel, 9psi, neo turbo, ls7 coils, exhaust, ic, q45 tb, freddy mani, few other things. Either way, with each upgrade i noticed a slight increase in power but nothing can match what a tune will do. Hopefully i can get it done soon....
let me ask u, what tire width and brand are u running?

[mantas]

265 continental sport contact in the rear. I had pilot sport 1&2 also 265.

[mantas]

It feels pretty quick to me if i dont drive the car for a few weeks but once i get used to it - its just mehhhh. Hahahha

[feito]

mhh weird, must be that freddy intake manifold taking mid rpm hp because i can spin them all the way up to 3rd on a dry day fully warmed up with 255 re11's on my stock ecu on 10 psi stock turbo. Now, i didnt follow on that "neo turbo", did u miss a coma? as in neo afc AND turbo? But anyway, i do plan on upgrading to a z32 ecu or a ve30 ecu when i upgrade my turbo, but for now i have enough and im sure op will be happy once he gets his shit running right.

[mantas]

mhh weird, must be that freddy intake manifold taking mid rpm hp because i can spin them all the way up to 3rd on a dry day fully warmed up with 255 re11's on my stock ecu on 10 psi stock turbo. Now, i didnt follow on that "neo turbo", did u miss a coma? as in neo afc AND turbo? But anyway, i do plan on upgrading to a z32 ecu or a ve30 ecu when i upgrade my turbo, but for now i have enough and im sure op will be happy once he gets his shit running right.

What i meant was - i got a turbo from a neo rb25, which makes no difference but is newer. I dont know it seems really hard to believe that you are spinning tires all the way to 3rd on a stock tune. Do you mean by dropping the clutch or if launching? If i drop the clutch i can probably spin 4th hahah. If i just put my foot to the floor from a stand still, it will light them up around 4500rpm but once i shift to second, it will only do a chirp or may be a little bit of a spin and then it just goes straight.

[feito]

My 4.11 final gear ratio help a lot. Driving normal (not dropping the clutch) i loose traction if i floor it at around 4-5k rpm on 2nd and sometimes 3rd depending on conditions. At wot my 1st gear's merely useless on the street, after taking off normal if i floor it i loose traction almost right away, maybe around 2k.

[mantas]

Well. That gear ratio probably helps. When i had an rb20 trans it would spin all the way to 4th too but not with the rb25 trans.

[bovaddict]

Car still feels slower then it should.. 11psi mines ecu And other mods in op.. Pulls "hard" until it feels like it should pull harder and it just doesn't, just starts to build lots of power and then it feels like it wasn't allowed to throw me back into the seat..

I have 245's on now and I can drift em but it doesn't burn in first if I don't launch and only chirps second on less then half tread all seasons

[ultimateirving]

Yeah man that wall ur hitting sounds like it could still be retarded timing.

Some other issues that are hard to diagnose but have caused similar issues:
Spark plugs blowing out, Intake pipe collapsing under suction, Knock sensor issues.

[bovaddict]

I have a solid intake pipe but the rest all seem very possible/likely. I'm gonna check em all/gap the plugs and report back

[bovaddict]

It pulls hard till like 3, then hesitates, then pulls meh at like 5500

[ultimateirving]

Just got beat by a 2001 impreza outback sport... Stock 2.2 5 speed

Uh oh time to sell the car.. Its ok, I missed second gear by overreving and lost an onramp battle to a v6 accord

[Yellow4g63]

LoL get a meth kit. I'm sure it was prob 150deg outside too.

[bovaddict]

It was hot out and a bit humid, but even now it's still off. A v6 accord has more then 146hp with awd powerloss..

I'm still checking things out(haven't had a lot of free time) and will hopefully report back soon with good news

[bovaddict]

Changed plugs today.. They had some carbon build up on 5 of em, the cylinder second from the firewall was wet and looked almost brand new?

Any input? I'm gonna test the coil pack tomorrow. That would explain it if I've only been runnin on 5 cylinders

[ultimateirving]

Coilpacks are a common issue on these aging engines. I know my sr would run, but would not pull hard because of a bad coil and it only got worse until i practically couldnt drive it.

[bovaddict]

That sounds exactly like my case.. It's a bummer :/

Oem coils 95-105 a piece
Split fire 500 for all 6
Ls2 conversion 150-250? But then I need standalone... So another 800+

Idk what to do but it's a bummer

[mantas]

That sounds exactly like my case.. It's a bummer :/

Oem coils 95-105 a piece
Split fire 500 for all 6
Ls2 conversion 150-250? But then I need standalone... So another 800+

Idk what to do but it's a bummer

You dont need standalone for ls2 coils. Been running mine like that for 2 years on a stock ecu. It was about $225 for everything but i just spent another $100 for longer wires so i could move them to a corner on the engine bay.

[bovaddict]

Orly?! I will look into this

[mantas]

Yeah my coils were arcing and car would spit or not pull properly. Got the ls2 coils and never had any problems. Also got rid of that infamous rb25 cylinder 6 misfire at idle. If you have an s2 its really easy to wire them in, s1 takes a bit more work.

[mantas]

Bahahahahha

[bovaddict]

Oil smells like gas, gonna change that and install my sandwich plate while at it. Wish me luck

New coil packs come Friday.. Oem for now but I'm saving for a pfc and ls2 coils

[ultimateirving]

Good luck, New coils will probably feel great in there.. And LS2 conversion is a good idea. Go to a junkyard and source them yourself for much cheaper

[mantas]

Yeah. I had no time to go to the yard but honestly ls1 ls2 should be enough for any rb. Ls2 was actually cheaper for harness plugs and wires thats why i went that route but ls1 or ls2 coils are fucking amazing. Before the conversion, when i used to take out my spark plugs they all varied in color slightly and were a bit gunky. I pulled them last week just to see and my 2 year old plugs look almost brand new. I could not believe my own eyes. With a pfc you can turn down the dwell to 5ms and you will be golden. But even on a stock ecu they are a great upgrade.

[ultimateirving]

Yeah. I had no time to go to the yard but honestly ls1 ls2 should be enough for any rb. Ls2 was actually cheaper for harness plugs and wires thats why i went that route but ls1 or ls2 coils are fucking amazing. Before the conversion, when i used to take out my spark plugs they all varied in color slightly and were a bit gunky. I pulled them last week just to see and my 2 year old plugs look almost brand new. I could not believe my own eyes. With a pfc you can turn down the dwell to 5ms and you will be golden. But even on a stock ecu they are a great upgrade.

Im pretty sure the LS2 coils are the desired ones because of the built in heat sink.. Amirite

[mantas]

Im pretty sure the LS2 coils are the desired ones because of the built in heat sink.. Amirite

Yes thats true but ls1 is more than enough and from all the research ive done no one had a prob with overheating etc.

[mantas]

And ls2 are a better shape so you can hide/tuck then much easier.

[bovaddict]

I wish I knew I could've done em without standalone, all the reviews/writeups talk about changing the dwell and I figured I was sol.. Well see how these replacements do and ill be wrapping em in electrical tape as well. I'm excited to hopefully feel this thing pull me to my seat

[mantas]

I wish I knew I could've done em without standalone, all the reviews/writeups talk about changing the dwell and I figured I was sol.. Well see how these replacements do and ill be wrapping em in electrical tape as well. I'm excited to hopefully feel this thing pull me to my seat

Well i have not had a problem since the upgrade, i did that wire look and electrical tape and i soldered all the connections. Just double check all the wiring before you start it up etc.

[bovaddict]

update: I adjusted the fuel pressure, confirmed the coilpack that wasnt working, replaced it, reset the ecu, and drove the piss out of it!

Shes alive. A big thanks to the guy who sold me the coilpacks, went above and beyond!

Went to drift practice yesterday and wow what a difference with the power! and the sound!!!!

[greenmachine300zxtt]

Thx for this info bovaddict wat type of plugs u using n how much gap? My friend with rb has same type of issue u had

[soundboy]

Nice to hear its performing well, I used to use a rb25det series 2 with automatic transmission. Used to literally throw me back in my seats. had a big ass turbo tho. 18psi