Hey guys,

I recently had my car retuned by GRD to 11psi making 480whp. However, after making a few highway runs last night i was just checking to see where my boost levels were at and i peaked at just over 15 PSi. I know this cant be safe for my car.

I am sure this question has been asked many many times, but what is the most we can realistically get out of our stock blocks? I have been running on this tune for 3 weeks or so and without any issues. I drive my car almost daily given the whether allows me to.

Which brings me to my next question, for those that have gone with the darton sleeved motor. How much power do u see urself making with the engine build (With stage3 heads)?

 

most Boost Gauges show higher boost readings I believe this is normal

 

Thank you, that was confusing me for a while. Any idea how much the margine of error on the guages usually is? Does the brand of the guages make any what of a difference?

 

I have the defi and it's usually about 2 psi more

 

oh dear, really bad advice.

What boost controller are u running? what turbo/s? First thing id do is take it back to the shop if u are no familiar mechanics and get them to check the pressures and make sure the wastegate is working correctly.

 

I beg to differ. When you tune the car and check the psi against the tuning software you will see the correct numbers while looking at the same time at the boost gauge it will be almost always be higher.
I have seen this now on several different cars and setups.

of course better safe than sorry so I wouldn't hurt to check it again just to be sure

 

We have noticed a discrepency as well, between the mechanical boost gauge and the engine management pressure sensor...

but, going from 11psi to over 15psi is questionable... get this checked...how is the A/F?
It is normal to see more boost on the street vs the dyno (airflow and increased load-can build boost quicker and more likely to overboost)...

I see about a 2psi difference at most, and this is between 18 and 20psi...4-5psi variance is too much- get er checked before I need to ship you a motor because you NEED one (not just want one- plus you won't have a usable core the vq35 comes in the "windowed block" option, but unfortunately, this model doesn't run)

-TODD

 

at 480whp I personally think you are driving on borrowed time and every mile at this point is gravy. I know tuan has his car over 500 on the stock block. That said, unless Irshad gets to drive it, I question how hard the car is pushed

You could have as strong motor and it could last a long time, but only time will tell.

seeing 15 lbs vs the 11 the tune was at is somewhat concerning. I know locals to me that run Defi BFs and see 4-6 lbs discrepencies vs EMS map sensors. That is on an STI running 25-30 lbs of boost though. I would take the car in for them to look at and at least take a spin around the block.

My questions to you are:
What does the car feel like? Does it feel like 15 lbs vs your previous tune?
Do you have a wideband?
if so, what are you seeing for AFRs when you gauge reads 15 lbs?
Do you have fuel pressure gauge?
If so, do you see fuel pressure taper when you start peaking at 15 lbs?

As far as your question about sleeved blocks. I have been researching them and have come to the conclusion that some say they are great, some say they are not. Most that don't think they are a good solution are those that have run them before. How much power are you looking to run?

 

The darton sleeved bottom end can handle lots of power, 700whp, 800whp, 900whp? (haven't seen a dyno yet for a street car at this power)

The Darton sleeved motor has better cooling capacity vs an unsleeved built motor, the sleeves are made out of ductile iron, extremely strong and the Darton setup converts the "open deck" design to a "CLOSED DECK"- improves the rigidity of the cylinder- prevents ANY movement under tons of stress (power)

I am runnign a very conservative amount of timing and 18psi, I make 600rwhp and 645ft lbs of tq..I know there is another 40-60 hp in there just with timing, and I feel comfortable upping the boost to 22-23psi (just don't see the need at this point)

I'll be happy to provide a quote for a builtZmotor- sleeved option..send me a pm and I'll get back to you shortly

-TODD

 

Why guys are spending WAYYYY to much money on this trick gauges that cant read accurately? I picked up my boost gauge off ebay for $20. It reads 100% (yes, ONE HUNDRED PERCENT) what my map sensor reads, which is exactly the same what the DYNO reads and which is exactly the same what my electronic boost controller reads. I have my laptop out datalogging and its exactly what my boost gauges reads.... Seriously, go upgrade now because ur block is stock and without accurate presure sensing, u will window it.

To the opening poster. Take the car back to GRD and get them to adjust the boost pressure to suit. Im guessing they didnt use a good load setting on the dyno when calibrating it. This is why a dyno dynamics dynos is such a fantastic tuning tool. U come off the dyno is a totally street-compatible tune.

 

The car feels like it is running much stronger. The turbos spool strong, and since we are finally getting some cooler weather i can enjoy it more too. My previous tune was at 8.5PSi and it does pull harder than it did then. If the discrepancies are always there, i suppose it is possible that is what it is in my case too. Unfortunately i do not have an AFR guage so i can not tell you what they are at 15lbs.


I am in the middle of a motor build at the time. I am doing the sleeved motor along with stage 3 heads and jwt cams, much more.. I bring it down to GRD almost weekly because im always worried since i do have it running this way. Havent had any issues with the car overall though, it seems to be handling the power fine.