Tuning help asap

djv1986

Member
So I've got gsr engine with forged turbo Pistons at 10:1 CR I'm torn between how much boost I want to run yet be safe and most power output ( like everyone ) I will be running 91 octane as its a daily driven car.

Should I

run 5psi and more timing

Or 10psi and less timing

I know the effective compression ratio is way beyond the realms of 91 octane at 10psi but theoretically speaking couldn't I reduce ign timing to get the pre ignition down and keep the engine safe ?? Water meth or the lht intercooler will be used
 

djv1986

Member
engine has rc550 injectors walbro 250 fuel pump stock gsr camshafts and engine is head studded block guarded and I think .030 head gasket
 

Muckman

Not a M0derator
Surprisingly your pistons aren't he limiting factor at all. You didn't say if you had stock sleeves or rods. But if you have stock sleeves then I wouldn't recommend more than 400hp - even with a block guard. And if you have stock rods then no more than 300hp as they are very weak. However we use real power metrics not psi as a yard stock as PSI greatly differs between turbo chargers and engine setups.

Finally RC550s will run out of injector around 340whp on gasoline which is the ultimate limitation on your setup.
 


djv1986

Member
Muckman said:
Surprisingly your pistons aren't he limiting factor at all. You didn't say if you had stock sleeves or rods. But if you have stock sleeves then I wouldn't recommend more than 400hp - even with a block guard. And if you have stock rods then no more than 300hp as they are very weak. However we use real power metrics not psi as a yard stock as PSI greatly differs between turbo chargers and engine setups.

Finally RC550s will run out of injector around 340whp on gasoline which is the ultimate limitation on your setup.
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It's a daily driver and it's Jackson supercharger I just added the Pistons figured someone would chime in about what Pistons I'm running. And the connecting rods are hbeam. Engine has stock sleeves +1.0mm over :( I know not smart haha. But what I'm mainly asking I guess is what's the difference between these two

10psi boost less ign timing
5psi boost more ign timing


Wouldn't both scenarios roughly end with the same outcome just one will have more timing then others? I had 8.3 psi before at 8k rpm it made 218whp ( stock Pistons/rods ) and broke both ring lands on 3 cylinders
 

xxBLOOD88SHOTxx

Surge Master
You had a shit tune for that to happen, plain and simple. The 5psi is not going to make the same amount of power as 10psi regardless of the timing unless your 10psi's timing is WAY too out of whack.

218whp on 8psi? Are those JRSC just rebadged hair dryers?
 

Samurai_Blue

Yolo Whippin'
my buddy was running 8 or 10 psi on a jrsc. 240whp 200tq on 91. stock rods, itr pistons .25 over crower stage 2 cams. His cams were the limiting factor for him.

I think its the tuner. We went to tuner A and the car wouldnt run well at all tuner B did everything right and it ran like a champ until he blew out the seals because of a lack of catch can.
 


djv1986

Member
Samurai_Blue said:
my buddy was running 8 or 10 psi on a jrsc. 240whp 200tq on 91. stock rods, itr pistons .25 over crower stage 2 cams. His cams were the limiting factor for him.

I think its the tuner. We went to tuner A and the car wouldnt run well at all tuner B did everything right and it ran like a champ until he blew out the seals because of a lack of catch can.
Click to expand...

I went to eriksracing paid like 400$ he loaded a premade tune and changing the dist. Location with his eyes and ears. Then made small fuel trip changes and that was my tune. I have s300v2 there's no reason he couldn't of made a new map for my exact setup.

Who do you recommended for tuning ?
 

djv1986

Member
xxBLOOD88SHOTxx said:
You had a shit tune for that to happen, plain and simple. The 5psi is not going to make the same amount of power as 10psi regardless of the timing unless your 10psi's timing is WAY too out of whack.

218whp on 8psi? Are those JRSC just rebadged hair dryers?
Click to expand...

Idk but it was a stock gsr engine with 8psi boost and injectors nothing else was done to it. I think that's pretty good considering it was using a LS trans also
 

Muckman

Not a M0derator
djv1986 said:
10psi boost less ign timing
5psi boost more ign timing
Click to expand...
These two tuning scenarios are consistent with all forced induction setups. As boost pressure (and cylinder pressure) increase ignition advance decreases. So any ecu would have less ignition timing at 10psi than it would at 5psi, thats a given. That doesn't mean that cylinder pressure is equal under both scenarios - if it was then both would make the same power and that would be stupid if not impossible. So make no mistake that 10psi with less ignition timing is in anyway SAFER because that's how it already is tuned anyways.

You didn't crack your ring lands because of too much boost. Maybe your tuner had too much ignition timing that caused detonation. Or maybe it was lean. Or maybe IATs were too hot which can also lead to preignition. Stock pistons are usually good up to 300hp, sometimes way more power. My point is the hardware wasn't to blame rather than the tune.
 

Samurai_Blue

Yolo Whippin'
was it on a dyno?

Elton @ Raceline USA loaded a basemap to my ecu and just redid everything from there. VTEC crossover, fuel maps etc.
 

djv1986

Member
Muckman said:
These two tuning scenarios are consistent with all forced induction setups. As boost pressure (and cylinder pressure) increase ignition advance decreases. So any ecu would have less ignition timing at 10psi than it would at 5psi, thats a given. That doesn't mean that cylinder pressure is equal under both scenarios - if it was then both would make the same power and that would be stupid if not impossible. So make no mistake that 10psi with less ignition timing is in anyway SAFER because that's how it already is tuned anyways.



You didn't crack your ring lands because of too much boost. Maybe your tuner had too much ignition timing that caused detonation. Or maybe it was lean. Or maybe IATs were too hot which can also lead to preignition. Stock pistons are usually good up to 300hp, sometimes way more power. My point is the hardware wasn't to blame rather than the tune.
Click to expand...

Hey were 100$ cast Pistons from EBay. And in the tune the knock sensor was disabled also. What sucks is the place who tuned my car " Eriks racing " I guess is actually a good tuner as some people say
 
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