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Mikes Chips, RSI Stage II: help me find the sweet spot.

Ursan

Ursan

Bored Member
Joined
Jun 14, 2004
Location
Satan's Kingdom, Ma.
Sort of a followup from this thread: http://www.turbobricks.com/forums/showthread.php?t=178158 But I didn't want to thread jack as I have some separate issues.

My car currently:

RSI Stage II Turbo Cam/RSI Adjustable cam gear currently @ -2?

1990 780 B230FT (stock block & head)
Crane Cams PS60 coil
LH 2.4 with Mikes chips (both)
90+ port matched.
Stock(ish) .43A/R with "H trim wheel" (can't find specs, bought over 12 years ago)Turbo
3" Exhaust with UIWG
3" Intake with 012 MAF and air-raid offset cone air filter. (mounted behind front bumper)
NPR (big one)
940 E-Fan
55lb Injectors(3bar)
NGK BPR6E (stock replacement out of the book) plugs @ 0.28"

I installed the cam straight up (didn't have the cam gear yet) & drove the car as listed above from last July (2009) until 2 weeks ago when I installed RSI adjustable cam gear. Cam is adjusted to the middle of spec on all 8 valves. I installed the hushers *after* I did the final cam adjustment.

It ran okay, but it wasn't terribly exciting. I was actually a little let down. But gradually the LH2.4 with Mikes chips did it's thing & things did improve.

I don't have a calibrated boost gauge (yet) so I'm not entirely sure what the boost level is, but it's "just past the yellow bar" on the stock gauge. I also don't have the wideband installed yet, but that's coming once I complete the move to the new house.

The idle is rough, but not overly so. It does have some other issues that I'd need help on as I just can't hear everything that's going on.

first, on damp (raining) days, there is a major miss under load. I've done my best trying to locate what ever it is that's doing it, but I've not been very successful so far.

Sometimes, even when it's dry, I "feel" a little miss, but I can't describe it any better than this. I'm mentioning this not as anything against RSI, I'm just throwing it in there as one of the issues I'm experiencing.

Cold weather/initial startup performance is not that good. If I let it warm up for 2 or so minutes & things settle out. Idle when cold is VERY lopey.

Now, when I installed the cam gear 2 weeks ago, I initially set the advance to 2? but didn't notice any additional low end so I then bumped it to 3? then to 5?. At each level of advance, I didn't notice any additional low end gains, but I definitely lost top end.

Here's where it get weird.

Last Thursday I set it to 2? retard & I got my low end back & then some. On top of that. I regained my top end and them some.

Does this make any sense? I was always under the impression that advancing gains you bottom end while sacrificing top end. Am I wrong on this.

I checked the ignition timing & it's right around somewhere between 10? & 15? at idle. I know I can't really adjust it with LH2.4, but that's where it is.

Also, when I do the adjustments, should I wait a few days for the LH to figure things out or can I just assume that that's what it's going to me once the adjustment is made?

If anyone has suggestions or advice about finding that sweet spot or point out where I'm going wrong, I'd love to hear it.
 
Get a boost gauge, and get a wideband, tho IIRC end of stock is around 15psi

The rough idle could be a Vac leak, Have you ever pressure tested the entire system? you might be surprised by how many cars 'run fine' but have vac leaks that fix a lot of their issues.

Have you cleaned out the AMM or IAC? how about the TB and intake manifold? EGR car?
 
Sounds like your cam is advanced a tooth farther than you think it is, so retarding it gives you closer to what your powerband is supposed to be.

That, and you have STOCK heatrange plugs in a motor that wants at least one step colder. Try BPR7ES or BPR8ES plugs in there to try and get rid of the miss(detonation), and STOP trying things until you can SEE what your engine is doing with the help of a boost gauge and a wideband oxygen sensor.
 
Get a wideband, running to rich can cause a slight missfire on cold damp days. And i cant believe you have done all the work that you have without a boost gauge.
 
Yeah, not having a permanent home makes working on the car kind of difficult. All the work mentioned above was done last summer. We were evicted in September. Wideband and boost gauge are sitting in storage & I can't get to them. We're just now closing on a house & I'll be able to get my tools & equipment unloaded. I don't believe that the cam is off a tooth, two sets of eyes checked & re-checked it. But I'll check it again as it never hurts. I've replaced all vac hoses, but I'll test for vac & boost leaks as soon as I have the stuff to do it with. Plugs are also a good idea. I'll pick up a set this week. Other than NGK, are there others I could consider?

AMM was cleaned prior to install last July. Throttle was jet cleaned and the idle valve hoses were replaced with the mods from last summer (org ones were cracked) The ports leading to & from the IAC are clear. other than that I don't know if anything I can do to the IAC than to replace it. This is a non-EGR car.
 
No real reason to go with anything other than the NGKs, as they're proven but I don't know what else is... :)
 
the autolites seem to be less prone to spark blow out from what ive heard. ive run the autolites at .35 gap and had no issues
 
Get Dave Bartons faceplate for your stock boost gauge! I really like mine, since it doesn't take up my precious A-pillar gauge pods. And it's only $20!!

new-gaugefront2.JPG
 
Autolites are the best. 64 is the number I run. .028 or slightly less with modified engines. They run smoother and accelerate harder than NGK in every volvo I've owned. I think a bigger turbo would wake your car up big time. That setup should move out in a hurry. You need a boost gauge badly. With the chips you should be solid on AFR but hell you never know unless you get some real data
 
by the way i feel your pain. The old lady liked to kick me out repeately so i had to get my own spot. I liked her garage better, however. I digress...
 
sorry I was replying to "Yeah, not having a permanent home makes working on the car kind of difficult. All the work mentioned above was done last summer. We were evicted in September." above
 
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