? for some motorheads

[wheatswake]

so i am getting into understanding the workings of a motor and looking into other mods besides exhaust,air intake,and tune. i have read that running a high octane (92/93) could result in pre-ignition/detonation. i have also read that the ecu adjusts timing according to the knock/crank sensor. (can't remember which one)

so heres my question

is this octane worry resticted to mechanical distributors or does is carry over to modern day ignition systems?

also can one simply do a cam-swap or do heads,rods,springs,rollers,and rockers need to be addressed with a cam-swap? will the ecu adjust the timing for the cam-swap?



is electronically advancing the timing with a programmer very minimal because of a stock setup?


i am just learning so forgive me if i dont word things correctly.

 

[Zed 71]

Higher Octane
- Running higher octane in today's engine is not an issue. If the ECU can not adjust accordingly, there will not be any benefit. Typically a tune is required to take advantage. However, for engines requiring high octane fuel, then there would be a potential issue running lower octane fuel such as knock, etc especially at full load (WOT).

Cam
- Recommend a dyno tune or at least an in person type tune to ensure all operating parameters are within spec and to make the most out of the cam swap.

Timing
- Advancing timing on a stock engine will have very minor gains (if any).

Good questions.

 

[wheatswake]

thanks for the response. i knew someone here would answer. i actually just kinda really meet my neighbor , who builds motors, and he said you can do just a cam swap (without dealing with rollers,rockers,rods,springs,etc.). but then brought up the point of going with a procharger system. doing this you don't have to tear into the motor. also he said it only takes about 3hp to run it opposed to whipple/magnacharger takes 15hp or more to run those systems. he said the procharger can result in up to 150hp. i dont know if thats at the crank or rwhp. i am thinking when my warranty is up, maybe going with a procharger system and blackbear tune. any thoughts about any of this? hoping jennabear will chime in since it is their tune i want.

neighbor also said he has a dynojet to check out rwhp. thought that would be cool to see actual results.

 

[Zed 71]

If you are still considering a cam swap, I would upgrade most if not all the associated valve train parts to make sure it is stout. Those parts should not increase the total cost by a lot and since that part of the engine is exposed already, the additional labor to complete is worth it. This is based on experience with other engines.

If you are deciding on which supercharger to go with based on 3 vs 15 parasitic hp, there are other more important factors because you will not notice that difference. Take a look at the power curves for each and compare where the curve suits your driving style or expectations. That is just one aspect just to give you an idea, there are a lot more factors to review that would be beyond forum discussions.

BTW, Jenna has the magnacharger.

 

[wheatswake]

good point on the other parts with cam swap.

i guess i want to know the pro and cons , magnacharger vs procharger, on a DD

 

[KMeloney]

so i am getting into understanding the workings of a motor and looking into other mods besides exhaust,air intake,and tune. i have read that running a high octane (92/93) could result in pre-ignition/detonation. i have also read that the ecu adjusts timing according to the knock/crank sensor. (can't remember which one)

I think you have the octane thing a bit backward, especially as it applies to a blower application. The higher the octane, the better protection against knocking. When you have a blower on your car/truck, it is the higher octane rating that allows you to advance the timing (have the explosion in the chamber happen sooner, somewhere before the cylinder is all the way at the top of the chamber, creating more pressure to push it back down = compression). When you have a blower, you need to put high octane in the vehicle, or else drive it with the timing backed way off, or else you run the risk of really screwing things up.

When I think about it, I suppose you don't have it "backward" -- maybe what you're suggesting is that if the octane is high, the computer could try to advance the timing on it's own... But, I don't know how/why it would continue to do so if it recognized pinging, either.

I just know that high octane is a must with high compression (blown) motors, and that a boost/retard knob accompanies any timing unit so that you can back out the timing if you sense any detonation.

 

[wheatswake]

on a stock setup-no supercharger
correct me if i am wrong but i understood that in modern day ignition systems the ECU constantly reads the crank and knock sensors and adjusts the timing accordingly. i have read that high octane 92/93 can create pre-ignition/detonation or bring the motor close to those phenomonons. i would think the ECU would see that high octane and adjust the timing for that. so i am thinking that if you are running 87 or 93 octane the ECU will adjust for it. now wondering if there is a cam sensor also the ECU reads. i was suggesting the ECU will adjusts the timing for 92/93 to correct the problem of pinging that the high octane can cause.

now bringing in a supercharger. the forced air that the MAF does not see (i believe that is how it is set up) the ECU will not see and then you would need a custom tune. correct me if i am wrong in this thinking.

ok after reading some more i think i am a little mixed up.lol

 

[Zed 71]

good point on the other parts with cam swap.

i guess i want to know the pro and cons , magnacharger vs procharger, on a DD

Wheatswake, contact Blackbear to discuss the superchargers, or at least post the blower curves for each so we can show you the differences in the powerbands. You will also need to know the differences between scroll and centrifugal blowers. That is your homework for today .

 

[wheatswake]

i will get my learn on and then call. lol thanks