Ignition Timing And Front Wheel Alignment

[wardy18 33 1 Cars]

Ok so because a wall jumped out and hit my pug at the last hillclimb i didnt get a chance to set it up properly with regards to ignition timing, can anyone advise what Deg at TDC and what RPM to set the timing so, im running a rally Catcam with a heavy head skim and twin 45 DCOE's with a re-curved dizzy by H&H?!

 

also

 

Because this wall hit my car i had to replace the 3 Rose Jointed Wishbones so i now need to re-set the camber and tow for the front wheels, what settings have you found to work well for hillclimbs with corner speeds of approx 40-50mph?!

 

Thanx

 

Simon

[DamirGTI 342]

Regarding the ignition timing , 31-32deg. total will do the trick but it'll be best that you try a few settings 30 , 31 , 32deg. and see on which settings is best ..

 

Rgs!

Damir

[wardy18 33 1 Cars]

thats great mate thanx, not sure how the marks on the flywheel will work cause ive got a Helix alloy one which had no single or double timing marks so i marked them on the flywheel myself when lining up with the old flywheel!!

[wardy18 33 1 Cars]

ok so to refresh my memory as its been a while, what would cause pinking - too retarded or too advanced and am i right in that you if standing infront of the car you turn the dizzy towards you to teh front of the car to advance and to the rear away from you to retard?!!?!?

 

at whats rpm should i set the timing too cause the haynes says like 2500 rpm at TDC or 600 rpm at BTDC..............which do i use?!

 

thanx

[DamirGTI 342]

Hi !

 

This might help , read trough :

http://forum.205gtidrivers.com/index.php?s...ignition+timing

 

Yes the pinking starts when you (over)advance the timing - turning the dizzy towards the front of the car will advance the timing and turning it to the rear will retard the timing .. or if you prefer like this : standing next to the dizzy (not in front of the car) looking at the dizzy - turn left to advance , right to retard .. Ok ?

Start turning (advance - turn the dizzy to left/to the front of the car..) in small increments of say 2-3mm at a time (mark each position in between the settings on the dizzy/thermostat housing so that you know how much you need to turn later from this position..) and go for a spin , pick high gear 4-th or 5-th and floor it from 2000rmp - if you can't hear pinking then it can handle more advance . Next , stop the car , turn off the engine , mark this position on the dizzy/thermostat housing and advance again a little bit more (turn the dizzy to left 2 to 3mm from the previous mark/position) and again go for a spin and test if it will pink in 4-th or 5-th gear when you floor it from 2000rmp. ... do this advancing procedure up to the point where the engine will start to pink , then when you hear pinking when you floor it in 4-5-th gear like explained stop the car , switch off the engine , again mark this position on the dizzy/thermostat housing and retard the timing (turn dizzy to right/to the back of the car ..) just a few mm-s , try 1-2mm first and again test if it's fine , if the pinking is stopped ... if not retard some more until it stops , and when it stops , when you retard from this "pinking mark/position" leave it and this will be the best settings..

The key is that you must find "balance" point in between the settings , retarding a few deg-s (roughly 2-3mm) back from the point where the engine starts to detonate/pink is the best position for power/torque.. (well a little bit more back but not too much !)

Also before this adjustment , pick the fuel grade which you'll be using afterwards you set the ignition timing cos if you adjust the timing this way on 97RON fuel it might start to pink if you fill it with lower grade fuel like 95RON and you'll have to again retard the timing a few mm-s back to compensate for lower octane fuel .. So use the same grade/octane petrol if you can , otherwise you'll have to tweak the timing a little bit if you mix various fuel grades ..

 

More precise way is with a strobe light , but you'll need to draw the timing marks on the crank pulley (or the flywheel) so that you can adjust it with the timing/strobe light at say 31-32deg.

But this “on the road” adjustment by ear will do for the start .. afterwards you can experiment with the strobe light when you make timing marks or even better book rolling road session and adjust the timing on the dyno .

 

Rgs !

Damir

Edited April 17, 2008 by DamirGTI

[wardy18 33 1 Cars]

hi mate

thanx for the info, a great help

the only trouble i have with the "on the road test" is that its a non road legal hillclimb car so i have now ay of testing it on the road, BUT like i said before when i fitted the new flywheel i did mark the TDC and BTDC on the new flywheel from the old one so i do have those marks ready to use with a strobe light and i can get hold of a digital strobe light so i think this will be the best way for me

 

my only question is at what RPM do you run the engine at and do i use TDC or BTDC mark when using the strobe light to get to 31-32deg?!

 

thanx

 

simon

[DamirGTI 342]

Ah , so it's track car only

 

ok. then plug off the vacuum advance pipe (you don't need the vacuum advance for race car anyway so my advice is that you just leave it disconnected all the time ... i have H&H dizzy for every day street car with blocked vacuum advance which reduces low down pinking so it can handle more total advance .. ) , run the engine at 3000rmp and set it 31-32deg. BTDC (before TDC) ... (try a few settings and see which suits the engine the best - 30 , 31 , 32deg .. )

 

Rgs !

Damir

[wardy18 33 1 Cars]

Certainly is mate, no lighting or anythin so wouldnt get very far on the roads which is why its a little hard testing and settin up, we have NO rolling road or dyno facilities on the island and certainly no track for a track day!!

 

I have already had the dizzy sent away to H&H to be re curved to the engine spec exactly, at the same time because i said i was running twin 45s they removed the vacumn advance from the dizzy completely so its perfect for the set up!!

 

ive marked both TDC and BTDC on the flywheel so ill find which one is the BTDC mark as one is a double mark and the other is a single mark then get the idle to 3000rpm and start off with 32deg, i wont know until i do a run if its pinkin or not, tomorrow is purely a set up day for me so ill see how it goes

 

thanx for your help mate

[DamirGTI 342]

I can't remember which is 30deg mark me thinks that theres 3 of them (on old 8v flywheels..), i think that i have three marks , one TDC mark , one 5deg BTDC mark (for static adjustment at idle ) and one 30deg BTDC mark (for dynamic adjustment with disconnected vacuum at 3000-3500rmp.)

 

Anyway if you have a 'variable delay' timing/strobe light you just need to find TDC mark on the flywheel and TDC mark on the timing plate (use some white paint to highlight the timing marks on the plate and the flywheel) and adjust the strobe light to flash at say 31deg. , point the light on TDC mark and turn the dizzy as needed to adjust 31deg-s ...

 

Rgs !

Damir

[wardy18 33 1 Cars]

ive attathed a pic of the 2 timing plates i have found on different engines, some plates have both TDC marks and BTDC marks but others only have one, i could never work out why!!

 

the top pic is the plate with only 1 mark and where the other would be the plate is shaped inwards

 

the bottom pic is the one with both TDC and BTDC

 

could never work out why they had different ones!!

[wardy18 33 1 Cars]

attatched

[DamirGTI 342]

True i have the same , one plate with both marks and one plate with just one mark :

 

 

They're both from 8v D6B engines (from 87year and from 90year car/engine) , from left to right the first one is a TDC mark and the second one is a BTDC mark .

 

Damir

[DamirGTI 342]

upss , just spotted now , i made a mistake mix up something here :

 

C/P from the beginning of the thread :

Yes the pinking starts when you (over)advance the timing - turning the dizzy towards the front of the car will advance the timing and turning it to the rear will retard the timing .. or if you prefer like this : standing next to the dizzy (not in front of the car) looking at the dizzy - turn left to advance , right to retard

 

It's the other way around : right -> advance , left -> retard .

 

Sorry

Damir

 

pic :

 

Edited April 23, 2008 by DamirGTI