LQ1 cam retarded ?

[Padgett]

Heard that the factory retarded the cam about 8 degrees on an LQ1 to limit the torque. Anyone know if it is true ?

[Psych0matt]

You're retarded...

 

 

I'm not sure what it is from factory, but I know a 6°/6° timing mod seems to work out great

[Galaxie500XL]

I guess it's possible...they just would have ground the flat on the cam the cam tool sits on, and instant retarded cam.. 

[Imp558]

I think we're supposed to call them "Special", what an offensive thread. I'll look in alldata and see if cam timing is covered at work tomorrow.

[Padgett]

What is 6°/6° ? About one tooth ?

 

ps been called autistic and AR before but not retarded.

Edited November 23, 2016 by Padgett

[Nas Escobar]

The whole LQ1 is special not just the cam lol

[MemphisMan]

I haven't heard that, but the following explains why the engine was retarded in the first place...

 

Also, just a good read.  This article has been around for a while.

 

http://www.angelfire.com/ca2/34Performance/dohc.html

[Padgett]

Also says "Delco electrionics solved the horsepower problem by cutting the fuel delivery and spark advance curves of the motor. This weakened it to a 6250 shift point, and 6500 rev limiter. Free-reving was limited at 3000RPM." Of course his is an automagic but wonder what the original fuel maps looked like, anyone have a copy ?

[Schurkey]

I haven't heard that, but the following explains why the engine was retarded in the first place...

 

Also, just a good read.  This article has been around for a while.

 

http://www.angelfire.com/ca2/34Performance/dohc.html

I'd call that a very well-done high-school English paper.

 

Obvious mistakes, and quite a lot of them.  But, yeah, for a high-school kid's English paper, I'd give it a passing mark.

 

I don't have any actual faith in it at all.

[Nas Escobar]

Just read that website... That's the first time I've heard that the LQ1 is descendant of the Quad 4 or that it inspired the Northstar/Shortstar engines. AFAIK, Cadillac was always doing its own thing up until Sigma came around. 

 

I've honestly heard so many crazy things about the LQ1 that IDK what to think anymore. I've heard it was supposed to be in a 2nd gen Fiero that never happened, that it's good for 280hp stock but was detuned because the 440T4 (later became the 4T60/E) couldn't handle the power, that it was supposed to replace the 3800. It's kinda crazy what people come up with.

[Padgett]

Well some has its roots in truth e.g. Buick in the 80's made just enough 3800s for their own use. The 440T4 (later 4T60) was designed for the 2.8 and was at its limits with a 3800 (in fact between 88 and 91 there were more TSBs on the 4T60 than any other element, the 91 4T60 had been beefed in nearly every component and was very reliable.

 

I see little design commonality between the Quad-4 and Northstar/Shortstar. Both used chain drive cams. Both were designed as individual engines. Norhstar was a 90 degree motor, LQ1 is a 60. LQ1 started as an iron pushrod engine (still has the original chain cam drive)

 

To me the LQ1 is a modified Chevvy V-6 with special heads like an Ardun Ford. Both Quad-4 and Northstar were complete designs. I have no doubt the Chevvy engineers studied the Quad-4 but is a completely different add-on design.

Edited November 24, 2016 by Padgett

[RobertISaar]

Just read that website... That's the first time I've heard that the LQ1 is descendant of the Quad 4 or that it inspired the Northstar/Shortstar engines. AFAIK, Cadillac was always doing its own thing up until Sigma came around. 

 

I've honestly heard so many crazy things about the LQ1 that IDK what to think anymore. I've heard it was supposed to be in a 2nd gen Fiero that never happened, that it's good for 280hp stock but was detuned because the 440T4 (later became the 4T60/E) couldn't handle the power, that it was supposed to replace the 3800. It's kinda crazy what people come up with.

 

some truth, LOTS of speculation and wishful thinking. there is some small lineage between the Q4, LQ1 and northstar, but it's nothing more than design conveniences. the 2nd gen fiero concept had inside of it an either 3.0 or 3.2 liter version of the LQ1(can't remember off-hand). transmissions are rated by torque and RPM limits, not HP(though if you want to get technical, torque and RPM define HP....), the 4.9 and 3.8SC were run up to the torque limit(280lb-ft), and the LQ1 already pushed the RPM limit at 6000-ish. the fact that you can simply retard the exhaust cams 13* and pick up serious output up to the 7000RPM redline is kind of wasted on the automatic(though if you have a manual, go nuts, your idle quality will suffer a little).

 

one of the fiero guys tested a few modifications to the LQ1 and found the cam retard to be worth 25ish HP up top, but the bigger fish turned out to be a modified 91-95 upper intake.... they shorted the runners a few inches(and I think slightly enlarged the plenum?) and ended up making 270ish to the wheels when combined with the 13* exhaust cam retard... this is all going off of memory though, I may have some figures off.

[Psych0matt]

So when my belt goes, 13* timing and put on 95 intake. Got it

[Padgett]

I would think that to boost high rpm performance, you would advance the cams, not retard them. Am I confused ?

[RobertISaar]

So when my belt goes, 13* timing and put on 95 intake. Got it

 

I hope you can weld aluminum.... and have some more significant injectors to go along with it. I think the 4.2 trailblazer injectors drop-in physically(need new connectors on the harness) and are roughly correct for the fuel flow required.

 

otherwise, might as well.

 

stuffs:

 

http://www.fiero.nl/forum/Archives/Archive-000001/HTML/20110502-2-104156.html

http://www.fiero.nl/forum/Archives/Archive-000002/HTML/20120111-1-083048.html

 

finding references to "Michael smith" as being the guy who made the intake+cam setup(but not finding the original threads...)

[RobertISaar]

I would think that to boost high rpm performance, you would advance the cams, not retard them. Am I confused ?

 

that's the reverse of traditional findings... generally, advancing the cam boosts low RPM output at the expense of high-RPM.

 

with intake and exhaust being able to be adjusted separately,  things can get messy pretty quickly.

[RobertISaar]

found the 8* reference:

 

http://realfierotech.com/phpBB/viewtopic.php?f=3&t=3137

 

that's stating that Michael smith had stock cam profiles, just that he retarded them 8* on the intake side and 18* on the exhaust side. word is that it is/was nearly undrivable like that, I can believe it.

 

 

 

 

and here we go, a good link to Michael smith's setup:

 

https://web.archive.org/web/20110503190458/http://fiero.cc/fiero-tdc/members/mws/intake/index.html

 

he mentions no real changes to the calibration, which is terrifying, and may explain the terrible driving characteristics(it should be "bad", not undrivable bad though).

 

only increased torque by about 10lb-ft(but moved the peak from ~4000 to ~6200), but the HP peaked at 7000 now instead of 5200, with a peak gain of almost 70HP. I think even the 284 is probably holding the engine back at this point, I can't imagine the clutch and input assembly liking the nearly 8000RPM this engine should be running up to.

 

I think with a slightly smaller plenum and a little longer runners(maybe an inch or two) to move the peak HP down to 6400ish RPM, what losses you would experience in the peak numbers you would get back 2-fold in being able to drive it in a non-maniacal fashion.

[Padgett]

err if you just move the same 211 lb-ft torque from 5200 to 7000 the horsepower goes up 69.

[RobertISaar]

yes, but stock torque peak is 4000. stock HP peaks at 5200.

[Padgett]

Really, I do not feel any real drop off until past 6500, is the curve different for a stick car ?

 

BTW just ran 109 miles of 50% 70ish, 30% 55ish, 20% city and gave 22.9 mpg at the same pump as yesterday. This is the best ever for my GTP. Do have the "highway mode" turned on now.

[RobertISaar]

That sounds how a normal LQ1 acts, with +6/-6 timing it starts dropping off hard after 6000.

 

There is some small change to the spark advance tables in manual vs auto, but the auto has significant torque limiting setup as well. Either way, it's worth 10hp around 5200.

[Imp558]

I don't think this is what you need but this is what all that has stock

 

[Padgett]

Are the mechanicals the same for stick and automagic - only difference is the maps ?

[RobertISaar]

there was speculation for a long time that the manuals got higher compression pistons, but I've never seen any actual evidence of it. the only physical difference that wasn't required to be a manual vs automatic engine is that the manual cars had one different exhaust manifold for the AIR pump.... otherwise, identical year for year.

 

in the calibration, the auto and manual calibrations run an identical amount of advance a lot of the time at high RPM/MAP. the real differences are that the manual calibrations have RDSC enabled and the autos have lots of torque management enabled. the "piston protection" stuff(which I need to see if that's actually mislabeled as it was in other masks and is actually cat overtemp) also looks to limit advance  a bit more with an automatic too.

[Galaxie500XL]

Really, I do not feel any real drop off until past 6500, is the curve different for a stick car ?

 

BTW just ran 109 miles of 50% 70ish, 30% 55ish, 20% city and gave 22.9 mpg at the same pump as yesterday. This is the best ever for my GTP. Do have the "highway mode" turned on now.

That's just a bit better than I got with mine. Daily driving usually came out right around 21 MPG on average. Best ever was an interstate trip to Georgia.. I averaged about 28.