need major help ka24det

[knmritz240]

I've had my s13 5 yrs now quick story.. 175k stock threw turbo on stock tune fmu8.1 Walbro tial wg open dump atmospheric bov 7.2 psi wideband steady13.2 wot for a year .. eBay stock rebuild same
setup .60 t3 7.2 add safc fresh motor 370cc greddy bc 9psi daily never a motor prob . turbo went I went to jail sold all parts except fmic n boost gauge and Walbro.. year layer I but .48 trim t3 no tune just Walbro ten psi blew two pistons second pull. been blowing ever since. I now have .50 t3 3 in exhaust tial 7.2 psi hks ssqv aem 1.1 fpr Walbro 255 new ngk wideband safc2 at first w 370cc now have enthalpy w n62 370cc n safc2 to make up for not having 550cc . she runs perfect one pull good another boom I've blown at least 12 pistons over 6 months it's stock build cams deleted egr clutch fan stage 3 clutch no emissions what do ever I am 240 like crazy but I'm lost and dono y she keeps piping low boost some one help

[knmritz240]

no one has any ideas?

[compactfean]

First off, for a turbod car .... Your first engine took a major beating as far as afr. 13.xx is so lean!!! Also enthalpy tends to have there base tunes pretty lean. (hit and miss) with any base tune I would highly recommend dynoing the car or if you have data logging capability monitor everything yourself. My guess is your engine is rather detonating or from running lean your combustion temps are way too high and frying s***. I would say your first engine was a trooper, lol. Monitor you're afr and get it to around 11.5 ish during wot. Also monitor knock. If you are having a fuel delivery issue that can cause you to lean out only closer to red line which you will want to datalog to find this out. If you can monitor monitor fuel pressure while driving, look for why pressure drops or pressure leveling out even though boost is increasing.

[knmritz240]

Ty for the reply. urs first motor was beast I've blown the third block at least 8 pistons.. not so much luck. being i have a safc2 and the enthaply and a ngk wideband can I data log?

[compactfean]

That might be half your problem right there is the safc. All that thing does is take your maf voltage and alter it before going to the ecu. That works very well for adjusting fuel, however, it puts you in the wrong load cell on the ignition map. Does the wideband have a commander of some sort? If so you should be able to plug it into a laptop and datalog your afrs. As far as knock, what you have won't get the job done. The enthalpy ecu only has altered fuel and ignition maps but still runs off of the stock computer. The stock computer cannot accurately read knock past like 4k rpms or so. I would recommend megasquirts ”knocksense” or a piggyback or standalone ecu that has a fast enough processor to read knock that quickly. this is if you want to tackle this yourself though. On the dyno they can monitor knock and you can simply send your ecu and the dyno run sheet back to enthalpy and they can adjust it.

[moso]

If your going to mess with megasquirt you might as well take the plunge and to ms1, its faster and more configurable than your stock ecu. its a breeze (comparatively) to install, infinitely adjustable, and you can get rid of that nasty MAFS!!

[knmritz240]

as far as the safc when I rebuilt the first time i tuned 9psi 11.2 wot daily almost a year then turbo went.. when input Safc in this time it was to make up for lack of injector.. ecu tuned for 550.. I have 370 I added 30% across board .. never blew on spikes of excess 15 on safc before now like I said its poping left and right.. tues lat week piston one fixed it fri and sat night blew piston 3 wtf.. never blew up while detonating for years now it's got a tune and she only pops.. I'll have to see if ngk wideband has a data port.. any good dyno tune around Daytona beach fl

[compactfean]

Mazworx is in the fl area..... They are top notch.

[compactfean]

However, I think you just answered your own question right there. Your adding fuel with the safc which is tricking your ecu into thinking its closer to red line. the extra voltage to your ecu causes the ecu to add fuel and timing. I would recommend pulling the safc and getting the right injectors for that tune, (which will give you room to grow) or get rid of the safc and send your ecu in for a reflash for you're current setup. either way safc has got to go.

[knmritz240]

humm .. thanks about dyno .. safc.. I figured ecu was correcting timing or boost so safc wasn't needing to so to say.. so maybe just baby it and take out safc to order injectors or trade both etc. unjust didn't think safc blew it bc never ever had probs before humm.. after 12 pistons just annoying.. spends thousands to boost and right at that and nothing but boom this time around

[compactfean]

I'm pretty sure if you just run the ecu and injectors and maf that are meant for that tune you will be happy. I was able to run 21 psi on a base tune from e-mance with no problems.

[lexcrob]

So the motor with the ebay stock rebuild faired pretty good? The reason im asking is because im doing mine with the egay bored .020 over and hoping im not making a bomb. I found civic and supra guys have great luck with them some 20k or more holding strong. My machine shop said they looked decent and i shouldnt have any problems. I may yank em out and mic the bore and see if i can use forged pistons. Ill have to measure and then call and see if its even gonna work as far as clearance i suppose.

Anyways on to the safc bash party. SAFC has a place and its honestly just a bandaid to help you get up and running. In a nutshell if you add fuel (make maf think there is more air) you in turn retard the timing. If you take a look at some base maps and read the MAF across the top and find a cell in fuel and ignition you'll see exactly how it works. In other words if you get a tuned ecu and take away fuel with it...... your advancing the timing. This also explains how many make decent power on a stock ecm and injectors. If you get larger injectors and have to "lean out then your back to advancing timing. Hopfully you also realize how important base timing is in relation to WOT. (also keep in mind base idle speed affects base timing! -refer to the FSM) Many people shoot the timing with a higher idle and advance it and say "wow its got so much power". Sadly this is because as your cars emission system ages it will create a higher idle speed then you just advance it but really you just put it back where it should be. To further elaborate your distributor gear will wear also causing timing to retard over time. There are still many other factors here but maybe that will help you out. 12 pistons......please invest in a safeguard knock sensor! <its kinda like a wideband easy to install i believe and you'll stop poping engines* i hope- let me know if it works good!!

[lexcrob]

these guys put it a little better:
http://www.dsmtuners.com/forums/tuning- ... tment.html

That is not correct, negative numbers on the SAFC will lower the amount of airflow the ecu is seeing, which in turn removes fuel and adds timing. Take a look at some fuel and timing maps. Lower load cells almost always have more ignition timing, when the safc tricks the ecu into seeing less airflow, fuel is removed and timing is advanced.

SAFC Tuning / How and Why

Read the 9th paragraph to verify what i said, then read the whole thing to get an idea of how the safc works in conjunction with the ecu



____________________________
-Luke

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03-28-2010, 01:14 PM Show Printable Version Email this Post #7 (permalink)
romeen
Proven Member


Car: 99 Eclipse GST
From: Vancouver, Washington
Registered: Jul 2006
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Reputation: Luke is correct.

The SAFC doesn't directly change timing. But since it alters the airflow signal to the ECU it makes the ECU "think" that the volume of air entering the engine is different from what it actually is. If the ECU "thinks" that the volume of air is more than what it actually is (+ adjustment on AFC) then the ECU might use a different timing map in effect pulling timing and vice versa.

[lexcrob]

Lets touch base on the FMU set up you had! 7.2 psi 8:1 fmu =57.6 stock fuel pressure 43+7.2 at full boost because the factory fuel pressure regulator is a 1:1

= 107.8

Thats actually perfect EFI fuel line operating pressure is max 100psi with a burst rating of 300psi so id say go back to that with a catch*

13.2 afr was because your turbo was to big for your set up! Bigger turbos flow more cfm in other word you should have used a 9 or 10:1 and just lowered the boost a hair. Its best to get to big an fmu then use a check valve and create an air bleed to fine tune it.

BLAHH anyways good luck at least you got the money im so poor i have to read and read and buy books and read...

[knmritz240]

thanks for the good info.. an yes my stock motor and rebuilt eBay internals stock motor both never popped.. I went NA for a few months and fuel pump took a s*** but I didn't know till I put a turbo on no wideband no exhaust no nothing and boom ever since I've out 2500 in parts and still boom.. I looked up into the safc today and set up my knock stuff so ima see how it looks in the pedal idling to full tach shows zero but in the last few days I fixed up some stuff.. little
ground on back of alternator came
off.. gapped plugs to 40 and new cap bc got messed up. so hopefully with the good afrs I have and watching knock will allow me
to pedeal it. hopefully the few fix ups stopes the pop as well. I'll let u know how it's going

[lexcrob]

tip: Retard you base timing more than you even think is safe. Get wideband and stuff all good hammer out the bugs like plug gap. Then go back to timing a very carfully bring it back up. With an SAFC your really playing with fire make shur you got a copilot with automotive ears to tell you that sounded funny watch guages with you!

Good luck and if you blow another one just go back to the fmu. If thats not enough give it to the professionals and pay extra to have it done right***. Professionals as in the best you can find and tell them I WANT IT RIGHT THE FIRST TIME IF ITS WRONG FIX IT IF THERES A PROBLEM LET ME KNOW.



Great to hear the ebay stuff held together im pulling mine back apart now from machine shop to check all their work and do some final mods. Still never got a piston deck height spec. anywhere guess ill be the first one to measure it in the frigen world. ......

i miss hondas everythings been done tried blown tested rebuilt and tweaked then put on a dyno!!!!

240 guys seem to just wreck there cars or keep quite about it or most chump out and grab up that seet jdm yo!

[knmritz240]

30 day later reply lol my bad . ok first tweaked a bit of stuff . new alternator.. other was going in and out plus found a ground missing.. didn't know if it was causing electrical surge ie maybe knocking. also hot knock part of safc working to monitor. 90 percent of the time it knocks more idle than under full boost. quick down shifts high rpm long gears sometimes hits a quick spike knock but usually stays under 25% knock if at all.. new tps .. var didn't move for a month now been driving 3 days now and still good.. the motor has blow by from blowing so many times so imnthinking maybe if the motor wasn't weak down low it would hold up like usuall. always had a wideband crusing Afr 14.2 at70mph put to floor in 5th. 7psi runs 11.2 wot any boost Amy gear.. I have a built motor I'm buying but waiting on some cash otherwise I'm bullying pistons n taking it to get honed and reringged with forged.. otherwise it runs good

[knmritz240]

oh and my b18t soon to be chrome always around and 6 years same s13 never give up I bring hope to all lmao boosted no matter what no mommy or daddy help bro

[knmritz240]

I actually beat the hell outta her last night against my b18 I pulled so hard but a few random pulls I was watching knock and had to let off others dull tach rev pop and slam a gear no knock at all . buying 550 right now install Tom or Thursday and out with safc only to monitor. I'm hoping that takes away a problem w knock randomly