3.4 DOHC baffled

[crazyd]

Wow, interesting revelation. Wonder what that means in my setup, with a stock 5spd computer running a '95 engine.

[RobertISaar]

not much. those engines were rated 210, just like the 91-93 manuals.... but the programming on them is WAY different and hard to compare directly. now that i have my notes open, they show 91-95 having roughly the same cam specs(so disregard statement on page 1 about 94-95 being better). the 96-97 cams are a bit different though.... look to have intake advanced by 4* and exhaust retarded by 4* compared to the 91-95 cams.... so kind of like the +6/-6 timing mod. except that the 96-97 setup also had the better heads and intakes, so while that cam change helped lower RPM power, they also had more output at higher speeds.

 

EDIT: actually, those changes may be in reverse of the normal +6/-6 timing change..... i'm not 100% on that.

Edited November 5, 2013 by RobertISaar

[Galaxie500XL]

Interesting, Robert...I wonder what would happen if you set up an automatic car to run the manual engine tune....or would that even be possible/advisable?

not much. those engines were rated 210, just like the 91-93 manuals.... but the programming on them is WAY different and hard to compare directly. now that i have my notes open, they show 91-95 having roughly the same cam specs(so disregard statement on page 1 about 94-95 being better). the 96-97 cams are a bit different though.... look to have intake advanced by 4* and exhaust retarded by 4* compared to the 91-95 cams.... so kind of like the +6/-6 timing mod. except that the 96-97 setup also had the better heads and intakes, so while that cam change helped lower RPM power, they also had more output at higher speeds.

 

EDIT: actually, those changes may be in reverse of the normal +6/-6 timing change..... i'm not 100% on that.

[RobertISaar]

Interesting, Robert...I wonder what would happen if you set up an automatic car to run the manual engine tune....or would that even be possible/advisable?

 

driveability issues, to say the least. especially off-throttle while at speed and coming down to near 0MPH.

 

the "easy" way would be to just remove the torque management from the auto calibration and add in the manual's RDSC spark adder.

 

 

 

also, +6/-6 advances the intake cam 6* and retards exhaust cam 6*. so intake opens slightly sooner and exhaust valve closes slightly later. both of these changes increase the amount of overlap that the engine will experience. so, 96-97 cams have a smaller degree of this ground in when installed via factory method.

 

according to Ben, -13 on the exhaust only raises the powerband noticably to about 6600 when it drops off, while +6/-6 tops out around 6200. stock.... well, HP peaks at 5200, but it doesn't drop significantly until after 6000. supposedly, the main draw of +6/-6 is that it helps out at lower speeds, but it also seems to reach a bit further out of the normal powerband by about 200RPM.

 

if only building a dyno were simple.....

[digitallyphoenix]

well not sure about the older ones but I made some pretty good gains when tuning my 96 and have sold a few PCMs for 96 and 97 LQ1 owners. the stock spark table had some major short comings. add to it that most if not all LQ1's i have seen run lean.

[OldMike]

I've noticed most people junk GM cars because they don't want to be bothered with fixing some of the rather off problems like the belt/chain, the gaskets, or because they mixed dexcool with green coolant. As far as the LQ1, most I see at the yard have relative low miles (130K - 160K) and are in ok condition. A to B type cars. I tend to notice most people just get rid of them when something on em is wrong and it is expensive to fix.

 

Or else when they've been trying to sell one for months and nobody seems to want it. Speaking from painful, personal experience here...

 

-Mike

[gambler87]

To answer the question of this thread. The fiero guys like myself and a couple others I know personally have found various vendors that have anything from reground cams to be custom pistons and milzy motorsports having headers ( expensive but the only option) for these motors.

 

There is a guy that did some really good math and found out where to cut the upper plenum of the high flow motors to make to intake resonance waves match the stock cams in the power band to make a little more horsepower. Tuned runner intake lq1 is what he calls it

 

Sent from my MB886 using Tapatalk

[RobertISaar]

i found a thread on PFF where it was showing that intake, claimed that when combined with altered cam timing(probably 0/-13), it made an extra 58 or 68HP? either way, impressive.

[Galaxie500XL]

I might be interested in something like that, Robert...I generally run premium only in my '95...and I have a spare ECM...tempting. I'm assuming the mods are in the spark table?

not really.... with a couple of keystrokes, the 10HP advantage that the 91-93 manuals have over the 91-93 automatics is back, if not more. i've done a premium fuel tune for someone running a 95 and they picked up ~5MPH at the end of a roughly 1/4 mile distance.

Edited January 2, 2014 by Galaxie500XL

[RobertISaar]

i would have to pull up the calibration file from my archive to find out, but yes, i would assume most of the work was done in the main spark table or through the torque management section.

 

you actually wouldn't need a full spare PCM(and MEMCAL), just a spare MEMCAL. which is easier to swap on a 95 LQ1, i wouldn't know.