I've got a straight through system and I noticed that the turbo manifold runners would glow red when I free rev around 2500 rpm.
Half bridge single turbo.

I've played with the timing, adjusting between 16 and 40 deg has no effect.

AFR of 13:1 + cause the red hot manifold
AFR of 11.5:1 causes the red hotness to go away.

So whats going on here? I would have thought I could free rev at 13:1

 

Have you actually checked it with a timing light vs just setting in the ecu? T1 & T2 harness wires swapped?

 

what ems are you running? your bast timing is probably off.

 

AEM EMS
I checked the timing via AEM's guide.
I'm not sure how you could swap the harness wires without trying really hard and I assume you would notice under any hard load.

 

so did you actually put a timing light on the pulley and then sync it with the EMS? should be in Configure --> ECU Setup --> Set ignition on the AEMpro software



The workshop manual ignition timing checking procedure for the FD:



I've never had to sync timing on an FD (FC you have to though), but your leading should be at -5 on the EMS with the light on the leading wire and the mark lined up.

 

Oh yes, that was all done, set leading timing to -5 set trailing to -15 and hookup the light to the trailing front plug to read the mark.
I am however about to buy a new timing light just to make sure as the one I have has an advance dial and I wonder if "0" means "0"

I suppose I can also try hooking up to the leading plug, run -5 deg on the leading and that should be my "0" for the pulley, correct?

 

Does the FD pulley have two timing marks (leading and trailing) like the older pulleys? Or does it just have one? If there's only one mark, does that mark correspond to -5 or -20? The old pulleys had a separate mark for -5 and a separate mark for -20. Even older ones had a mark for actual TDC. The leading mark appears to the left of the trailing mark when you turn on the timing light.

 

FD only has a mark @ -20btdc. there is no leading mark stock

the 83 and older cars are TDC and -20BTDC/20atdc, as the idle timing is TDC and -20

 

When you run the ignition timing wizard I would think that the EMS locks the timing to whatever value is in the leading and ignition difference maps. Therefore if I were troubleshooting it, the first thing I would try is this approach:

1) Save your previous main ignition map. Set the main ignition map to -5 across the board, or at least in the idle area.



2) Save your previous ignition difference map. Since -5 minus 15 = -20 , set the ignition difference to -15



Thus the EMS would be set to a fixed -5L and -20T.

3) Attach the timing light to the front trailing plug wire

4) Activate the timing wizard. Advance or retard the timing until the mark lines up. The ignition timing parameter in the timing wizard would stay the same (-5 degrees) but the mark on the pulley should appear to move left when advancing and right when retarding

5) With the timing mark aligned to the pointer, we know that trailing is at -20 degrees. Since leading is 15 degrees advanced from the trailing, the leading should be at -5 and you should be set.

6) See what happens to the timing mark when you try to open the throttle and raise rpms

I've never had to do this approach on an EMS but it makes sense to me.

So did you do what I just recommended or did you do something else? I'm not 100% clear on how you went about checking the timing.

 

The procedure that I said is the same procedure that you listed.

 

do you have EGT probes in the manifold runners?

 

No

 

I dont think that is very unusual to be honest. If anyone has EGT guages youll see temperatures get hot with revs and leaner mixtures.

 

Yeah I figured it has to be normal at this point. I've verified timing with a different timing light yesterday. I went out and drove it around and did some WOT passes, my AFR at WOT is 11.5:1, everything feels like it should, no strange going on.

 

for what it's worth, I notice the exhaust manifold tends to heat up like that when I am part throttle tuning FD's on a loading dyno.

 

Well here is a bonus video just in case. This was at stoich.
http://www.youtube.com/watch?v=VOuV0n6gXsM

 

What gauge tubing is used for your manifold...?

 

Whatever the RX7store brand is. If I was to guess it looked like .090

 

Retarded timing, vacuum leak, extreme rich or lean condition, or natural high idle...

You never stated what your "idle" point is, can you elaborate? Have you sprayed carb cleaner around?

 

Your trigger wheel on correct? Check it. Could be retarding timing and you don't know it. This is easier to do if your running the Tec trigger wheel, but still worth checking. What are your egt's at idle?

 

Idle is set to 1500, no vacuum leak.
Manifold is not red hot at idle, it gets hot when free revving to at least 2500 rpm

An interesting theory, but I'm running a stock wheel and isn't it apart of the pulley?
I also have advanced timing up to 60 deg while testing, more than enough to compensate for something that is "off."

I do not know what my EGTs are, I do not have a gauge so all I can say is that it doesn't glow at idle.

 

the stock trigger wheel is serperate from the pulley but that should not be a issue. If you have done the base timing then i would not worry about it. If you see egt's going over 1800 then i would start to worry. The stock trigger wheel on a fd works just fine with no issues at all.