My car has been Dynoflashed with the mods I currenty have. I am concidering adding a uprgraded Intercooler, and was wondering if by adding the intercooler alone would screw up the fuel curve flash. Or if I were to add a fuel pump in addition to the intercooler would I need to be reflashed??? Any experience, Help??? Thanks

 

yes with the fuel pump you would need a reflash i dont think so much for the intercooler but fuel pump yes

 

fuel pump yes. Intercooler No.

 

what the hell, you people are crazy with the reflashes. if you change fuel pumps you DO NOT need a reflash.

let me repeat you do NOT need a reflash if you change fuel pumps.

one more time so that misinformation doesn't get passed around anymore, fuel pumps do NOT require a reflash


and for the explaination... the fuel pump does nothing but supply fuel to the rail. the fuel pressure regulator is what controls how much fuel pressure there is. changing fuel pumps does not actually change anything at all relative to fuel pressure! when modifying an evo heavily, if you were to exceed the stock fuel pump, fuel pressure would begin to drop off at high RPM's... this is not the case with the stock pump until you are significantly modified. changing it out will allow you to make more modifications, supply more fuel, and not get the drop in fuel pressure under WOT at high RPM's.


so to clarify, if you change fuel pumps you do NOT need a flash.

 

But doesnt it run richer since your adding more fuel? Mening getting it retuned

 

That is my main concern.

 

you are NOT adding more fuel!!!!!!


changing pumps does not increase the amount of fuel at all! it is the fuel pressure REGULATOR that changes the amount of fuel going to the injectors. if you are experiencing fuel pressure drops due to maxing the flow rate of the stock pump, then you need a bigger pump, but you still DO NOT need a reflash. if you change regulators, then yes, you will need a reflash or injector scaling or something along the lines of that, but pumps, no.

 

Your explaintion seems logical, I just was told by dynoflash that if I ever upgrade the fuel pump either to do it before flash or reflash if I add it later...which doesn't make sence. Either way If I just added a intercooler is it a common practice to upgrade the fuel pump because of the denser air over stock. Or am I ok just to bolt on a upgraded intercooler? Thanks

 

I would think the regulator still control the amount of fuel being delivered. I would also think adding a bigger Intercooler, could be used to get more HP with a Dyno Tune.

Maybe should be asking a Tuner these question, instead of the public.

 

Maybe should be asking a Tuner these question, instead of the public.[/QUOTE]

Most of the people have experience in this area personally to their own cars, hence my post and the reason for the whole "Forms" process. Thanks for the tip though.

 

https://www.evolutionm.net/forums/sh...d.php?t=221963

After he put in the Walbro (and doing nothing else), the guy was running extremely rich at high rpm's. I would reflash it if I added it after my tune.

 

I thought Buschur decided that he woould not flash ANY VIIIs without having already upgraded the fuel pump. From what I have read in the past it will make the car run richer and does require a flash, but KevinD seems adamant that this is not the case.

 

i tune race cars. i am also a mechanical engineer who has built race cars. al was a LAWYER... he now makes money selling you tunes... i wonder why he is going to tell you to get a flash after every single change you make.

if you want a detailed point by point explaination i'd be happy to draw a diagram.


but let me try one more to to make this crystal clear...


lets say you have (4) 55lb/hr injectors. these injectors are rated at a certain fuel pressure... lets say 50 psi.

we all know that the fuel pressure regulator (herein abreviated at FPR) keeps the fuel pressure at 50psi ( i know, it is referenced off manifold pressure and it will increase with boost, but for the sake of this explaination, ignore that). if you have a pump that can pump 5 gallons per minute, fuel pressure will be 50 psi. if you have a pump that can pump 5,000 gallons per minute, you will still only have 50 psi fuel pressure. now, lets add in the injectors...

injectors open and close, allowing some fuel to pass through them. because they are rated at a certain flow rate at a certain pressure we can calculate how much fuel is being let into the engine, but know this: the ONLY parameters that will effect the amount of fuel being injected are pressure, battery voltage and injector signal pulse width (there are others like temp, friction, etc, but we can ignore those). thus, if we have 4 injectors that are releasing 3 gallons per hour combined (about the amount of fuel getting 20 miles per gallon at 60 miles per hour), then all we need is a pump that can supply more fuel then those injectors are consuming. let me show you:

injectors use 3 gallons/hr

pump is capable of supplying 5 gallons/hr

that means with FPR hold pressure at 50 psi, there is 2 gallons/hr that is returned back to the fuel tank via the return line. the FPR can always do its job as long as there is enough fuel that it needs to go through the return line....

now with a bigger pump:

injectors use 3 gallons/hr

pump can supply 5,000 gallons/hr

FPR holds 50 psi still, and 4,997 gallons of gas/hr go back to the tank. thus injectors still inject the same, fuel pressure remains the same, you are just moving a ton more fuel around.

now for the case where you do need a bigger pump:

lets say injectors now are using 15 gallons/hr (what you would see on the race track approx...)

fuel pump can only supply 5 gal/hr.

FPR cannot maintain 50 psi because the pump isn't even supplying enough fuel for the FPR to do its job. remember, the FPR can only do its job if there is more fuel being pumped then fuel being injected.

and with the bigger pump:

injectors use 15 gal/hr

pump supplys 5000 gal/hr

fpr holds 50 psi because we still have 4,985 gallons/hr flowing back to the tank.


is that more clear? i'm sorry if i am coming off as a jackass this morning... i just don't like it when people spread misinformation for their own profit.

 

I understand your concerns for valid information. As I stated you were pretty adamant that you were correct, and I'm sure that you know better than I do. Everything yo usaid above makes perfect sense, but I don't think that Al was the only one spreading this information. I'm sure if you aren't correct that someone is going to be more than hapy to have it out with you. That person won't be me though. If it turns out that you are correct, then I guess I can go ahead and install the fuel pump that has been sitting in my car for four months waiting to get a flash.

 

i was told by ivey that you will need a tune if your boosting over 23psi. other than that. you can upgrade your fuel pump to walbro 255 without a tune.