Max "safe" ballpark timing advance range for our motors with blowers on em?

S

SIZEMOREMK

Junior Member
What would be the max "safe" ballpark figure for timing advance range for our motors with blowers on em?

I know it is a loaded question and depends on quite a few factors, but where is the number where one might start getting concerned?

Seems like I have seen the 14* number thrown around a time or two for blower cars?

Mine in particular is a centri, around 13psi, 9.5:1 compression... Teksid block, heads have some kind of aftermarket valves, intake cams are slightly "bigger" than the 98 cobra cams, with an oversized and overpriced custom Bell intercooler.

I went with a local fella here more familiar with LS motors, but has a "ford/cobra guy" that consults with him on the ford tunes...

Would really like to have a more informed and productive conversation with the shop as they near completion.

He tells me they got 511/460 WRHP/WRTQ at 13 PSI, but mentioned that this was at 17-18 degrees of timing and feels that was a good place to leave it at. The fuel wasn't exactly where he wanted it, so he has swapped in an aeromotive 340 and also has to work on a different BOV/Bypass valve issue before he gets it back on the dyno and continues to tune.

That timing figure seemed a little high to me but I'm no tuner, nor did I stay in a Holiday Inn Express last night, so I am not really qualified to have much of an opinion on where the timing ought to be...

I have not verified, but they were suppose to replace the knock sensors that had previously been removed, so maybe that gave him some more flexibility??

Mainly just curious how much timing similar setups are running?

Thanks guys!
 
With that compression I'd set it at 13-14 tops.
Cars don't usually ping on the dyno, since a real world load cant be duplicated.
There are also many places in the rpm range the MM will ping depending on what gear you are in.
Tuning a heavy car isn't always easy.
 
Mike M said:
One of the reasons I run water/meth.
Click to expand...


So I have a snow kit that I was thinking of using, tested it and made sure the controller and pump still worked.

Talked with the guy about using it and he recommended that it would be of no use unless adding extra timing to the tune, where if it failed it could cost a motor.

I was thinking it could be used with the smaller nozzle, as more of a buffer to help against knock or a random bad tank of gas; such that the motor wouldn't let go if the meth failed.

This is the way I used it, or at that was my intention, in my previous Tbird SC with an aftermarket Magnum Powers heaton M90 based roots blower. The boost guage in that car maxed at 15 psi and it pegged that, and this was on a 3.8 V6.

I felt that it worked well in that application.

It's a funny coincident that when I recently took the sow kit off that car it blew a headgasket the first time I beat on it pretty good.

I ran that car for a year or two in that configuration without an issue. Now I have to do a headgasket job on that bish before I sell it:bigcry:

So who uses the water/meth in a manner that is dangerous in the event of a meth failure?
 
If your running a centri why not add the snow kit with more boost.
I wouldn't use meth to get high... :eek:
I mean cover up high timing. :shake:
 
rauder88 said:
If your running a centri why not add the snow kit with more boost.
I wouldn't use meth to get high... :eek:
I mean cover up high timing. :shake:
Click to expand...


Well I am running close to about as much boost as I think this little blower will give me...

It is the smaller Novi1200, and I have an 18% damper with the 3.33 pulley. The max suggested impeller speed of 5200RPM is maxed out at just about 6200 engine RPM according to the calculator. I know I can spin it a bit faster, but I wanted to keep things in a safe range.
 
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SIZEMOREMK said:
Well I am running close to about as much boost as I think this little blower will give me...

It is the smaller Novi1200, and I have an 18% damper with the 3.33 pulley. The max suggested impeller speed of 5200RPM is maxed out at just about 6200 engine RPM according to the calculator. I know I can spin it a bit faster, but I wanted to keep things in a safe range.
Click to expand...


Ya, don't over spin head unit.



Sent from my iPhone using Tapatalk
 
The vortech tech said their max impeller RPM (52Kish depending on model)is a function of the bearings, but also said plenty of guys ignore that limit.

I know of cases where guys overspin them without issue, but at some point efficiency drops off and generates more heat, which would begin to negate gains in addition to wearing the blower out faster.

I know of one guy that spins his centri closer to 60K+ impeller RPM at redline and has for tons of daily miles... But his is a different unit that moves more air than the novi 1200.

But I am curious where the real limit is???
 
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