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Car Runs Great At 20* Compared To 15* Timing

240dreams
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240dreams Apprentice

240dreams

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Car is a 89 S13 engine is a Series 1 RB25DET.

For some odd reason my car runs like crap on stock timing. There's just no power up top and it feels really rough. It makes lots of noise but doesn't really go anywhere. But when I set timing closer to 20* BTDC, it feels much better. It has more power and it comes on a lot smoother up top and down low. I know for a 5spd RB25 stock timing is 15* and for an auto stock timing is 20*. But my engine is a 5spd manual. I'm really stumped with this and I don't want to ruin my motor by running incorrect timing. Has anyone had an issue like his before? Any help is appreciated.

240dreams Apprentice

240dreams

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Car is a 89 S13 engine is a Series 1 RB25DET.

For some odd reason my car runs like crap on stock timing. There's just no power up top and it feels really rough. It makes lots of noise but doesn't really go anywhere. But when I set timing closer to 20* BTDC, it feels much better. It has more power and it comes on a lot smoother up top and down low. I know for a 5spd RB25 stock timing is 15* and for an auto stock timing is 20*. But my engine is a 5spd manual. I'm really stumped with this and I don't want to ruin my motor by running incorrect timing. Has anyone had an issue like his before? Any help is appreciated.

Is that +6 degrees over stock timing (21* BTDC). How modded is your engine?

mad082 Grand Master

mad082

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how are you checking your timing? is it possible that you have infact been moving the timing the other way and dropping it to 10*btdc?

also what fuel do you run? if it is crap fuel then that may be the cause. set it back to 15* and put some good octane boost in and drive it round for a bit and see if that makes it run any better.

240dreams Apprentice

240dreams

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I'm checking timing with a Snap On timing gun using FSM procedures.

When I was setting timing to 15*, I aimed for the 4th mark from the left on the crank pulley.

For example: l l l l <---This one

0* 5* 10* 15*

I'm running 93 octane fuel (highest grade available here). I'll try octane booster to see if that makes a difference or not at 15* BTDC.

I just went back out for a quick drive. I don't really want to drive too much b/c of my lack of fans. But I noticed that at 15*,17*, and 20* my car felt slow. It honestly felt more sluggish than a stock KA24DE. So in desperation, I rotated the CAS completely counter clockwise (advanced) and went for another drive. It felt great - like a 6 cylinder turbo should. Albeit it wasn't too smooth due to some ignition misfires but it actually felt fast and it knocked my head into the seat. None of this occured at close to stock timing. I'll have to wait to get some fans on before I got out for joy rides again. I don't think I've been doing my engine any good running w/o fans.

Sydneykid Grand Master

Sydneykid

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Posted

One of the things I notice with guys new to RB’s is they tend to point the timing light vertically, straight down at the timing mark on the cam cover. This is wrong, the timing light needs to be 25-30 degrees off vertical, towards the airfilter, (the RHS looking at the engine). If you point the timing light vertically you see about 5 to 8 degrees advanced from where the timing really is. Move the light (and your head) across to the right and you get a better indicator of the real timing.

:) cheers :)

240dreams Apprentice

240dreams

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Posted (edited)

I'm new to RB's but I'm not new to Nissans and timing them in general. Also, I'm a techinician for Honda.

I'm definitely pointing the gun correctly. I also learned that it's easiet from the right hand side. The timing indicator is also easier to see from that angle.

Edited by 240dreams

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