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Am I overboosting or what? (weird smoke spurts)

1K views 13 replies 7 participants last post by  Blaast 
#1 · (Edited)
Hi guys,

My lude is still working well, don't worry!

However, I might have reach a limit on my setup:

At 7-8 psi, It works like a charm.
At 10-11 psi, the car pulls like crazy (although I know it could be better because it tends to get over-rich: 11.x:1)"
but I'm spurting some smoke as soon as I reach full boost. OOps, I think I gonna have to fix something before I flick that DUAL stage boost controller switch again!!! :)

I have a stock head gasket and studs. I bet I'm lifting the head under boost.
What do you guys thinK?
 
#3 ·
i thought i read on here that studs were good to 20psi. some guy preeched a story about being at the track and running 18 fine and lifting the head at 20-22~ and said to stay below 20. I think search might help, no? this is all from my memory, which could be wrong. search is known to state facts (fact) :p
 
#4 ·
Blaast said:
Hi guys,

My lude is still working well, don't worry!

However, I might have reach a limit on my setup:

At 7-8 psi, It works like a charm.
At 10-11 psi, the car pulls like crazy (although I know it could be better because it tends to get over-rich: 11.x:1)"
but I'm spurting some smoke as soon as I reach full boost. OOps, I think I gonna have to fix something before I flick that DUAL stage boost controller switch again!!! :)

I have a stock head gasket and studs. I bet I'm lifting the head under boost.
What do you guys thinK?
Depends...I assume you're using ARP studs? I had a problem lifting the head at 13-14psi but that was on stockers before the ARPs were available, haven't had a problem since. Did you get any coolant pushed out or notice any bubbling in the coolant bottle? I wasn't making any smoke when lifting as the combustion gasses were pressurizing the cooling system.

What color was the smoke? If it was black then you just need to work on leaning it out at higher boost levels...with mine I noticed that when it headed south of 11.3-4 I'd start smoking like a freight train.

--Ian
 
#5 ·
No, I don'T have ARP studs. Only the stock ones. I did not notice any coolant bubbling NOR saw any sign of oil contaminating the coolant or the opposite. Therefore, I think the head is OK.

Not to sure about the color of the smoke but I'm sure it's oil because when I boost a lot, I can empty a quarter of oil in day. If simply cruising around, Oil level doesn't drop that much. Today, I just noticed that My A/F behaves like this:

idle and cruising: 14.3
early WOT: 13.x
Full boost 13.x gradually reducing as RPM increases.

If I insist a lot on boosting until 8000RPM, the A/F ends up in the 11:1 and even the mid 10:1... That's rich.

When trying this, something strange happened: When boosting at 10 psi, I eared a "POP" in the exhaust followed by a big spurt of smoke. Is that a surplus of unburnt fuel??? MAybe it is washing the cylinder walls and causing oil to leak out ?

However, the smoke puffs occur right when boost gets on, and at this time, the A/F is still in the 13:1, which is not too rich...
...Unless my APEX'i A/F meter is a bit slow?? Possible: it must average data on quite a large time span to have such a stable reading. Yeah, maybe this A/F ratio is delayed...

Finally, maybe my 550ccm inj. set at -50% on the VAFC is a bit too much. I'm gonna try those 440ccm at -40% instead...
(running the hack, of course)
 
#7 ·
AHAH!!! I don't think I blew ringlands on my JE pistons. I still have a solid 24 psi vacuum at idle and my J&S has a quite conservative setting for my setup. 0.6 degrees/psi.

I prefer the hypothesis that my problem is a fueling problem. I need to verify it. I'll receive thoses 440 ccm inj. shortly. Can't wait.
 
#9 ·
HEllo!

A little update: I swapped my 550 cc/n injectors for some DSM 450 cc/m injectors. Then, I use the VAFC hack at -40% and -35 Under boost (with the hacked TPS wiring).

The A/R is still at 14.3 when cruising but at WOT and under boost, the A/R is at 13.5 and it slowly goes down as the RPM increases to reach 12 at red line. But in the power band, I'm in the 12.5-13 range, which produces a lot more power than before when I was playing in the 11 and sometimes 10:1...
I will work on leaning the mixture to -45, under boost, at 7000+ RPM to compensate for this tndency to richen at high RPM. Maybe it's due to that huge Bosch pump...

I also noticed less smoke behind the car when I'm boosting. Finally Maybe I was burning excess fuel and not oil...

Anybody interrested in my RC engineering 550 cc/m injectors??? :)
 
#11 ·
I had the same problem, but only because I was running real rich in boost to prevent problems hah. I also didn't have a cat.
 
#13 ·
zip's smc :



Hey guys, I haven't been surfing this board lately since I've been tirelessly working on the SMC. I'm proud to present a sophisticated electronic device from ECG Performance Electronics that will enable Honda/Acura FI setups to ditch their FMUs with stock injectors in favor of larger injectors (i.e. 450cc) and the SMC.

The SMC is an acronym for Super Map Controller. The SMC features:


-Controls larger injectors up to 440cc to 450cc for FI setups with factory ECUs
-Real-time MAP voltage correction for unparalleled drivability under idle, daily driving, and boost
-Smoothens transition from vacuum to boost
-Active internal MAP clamping to prevent a check engine light*
-User programmability
-Supports boost ranges from 1-14psi on Honda NA ECUs
-Fuel trim, up to -55%, on four rpm levels
-Precise idle fuel control
-Unlimited rpm range
-Ultra-fast 20MHz RISC processor
-Easy installation
-Stealth. Small and compact design
-Works with other factory NA engines and factory boosted engines with a MAP sensor
-Affordability. Introductory price of under $100!!!

* MAP clamping can be removed for use on factory boosted engines. (i.e. WRX, VW 1.8T, etc...)


....

in the end, i think this will probably yield similar results to the vafc hack.
 
#14 ·
Yeah! Good idea. I thought about that too. The VAFC and all it'S fancy functions might come handy for tuning but is overkill since -40% accross the band is sufficient.. I was first thinking of simply installing a resistor corresponding to -40% on the injection signal.
That's even better, it'S a variable resistor. It doesn't have to do any "MAP clamping " since the MAP voltage with 450cc/m is reduce enough to avoid any CEL anyways.

COrrect me if I'm wrong but I thing that while this is an excellent and cheap alternative to the VAFC, you don't gain much from it if already owning a VAFC ??!?!?
 
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