motor runs great.. slow at 7 psi.. high comp pistons..

[DJYoshaBYD]

ok... Im running a NA JDM 6bolt in my 91 TSi AWD... I was told that I cannot run more than 8 psi with the 9:1 compression in this car without getting knock... that seems kinda awkward... I hooked up my stock boost solenoid just like how the manual says and it wont boost past 7 psi and it is SSSLLLLOOOWWWW.... very slow...

question 1: why is my stock boost solenoid only letting my turbo boost to 7 psi?

question 2: is it true that I cannot run more than 8 psi without knocking? I have a rewired fuel pump so I know that fuel is not a problem, but I have to run more boost.. its just to slow...

 

[freshlane]

You cannot run more than 8 w/o blowing it I believe. Mayb the solenoid is hooked up wrong because I thought the 14b wg is set a 7psi, which is what you are getting

 

[DJYoshaBYD]

well.. the 4G63 NA and the turbod model are the same thing... rods and all... different is:

pistons (NA=9:1; turbo=7.8:1)
exhaust cam (VERY little difference)
water pipes
oil filter assembly
Oil pan
Oil squirters
throttle body

I swapped everything from the turbo motor to the NA motor... Im asking because somebody was saying at anything above 8 psi will cause spark knock, which will damage a motor.. I fixed my MBC and turned it up to 10 with no knock... I only run 91 octane and the car feels solid with no stuttering or anything...

 

[JayRolla]

It should still run strong at only 7 psi. I would have the motor compression checked and make sure you have no boost leaks. Im running 8.5:1 pistons and I wasnt able to run more than 11psi on stock fuel system.

If you have a logger just up the boost till you get knock then go back to where you didnt knock. If you have no logger do not run more than 7psi.

 

[DJYoshaBYD]

7 psi was sssllloooowwwwwww..... My friends focus with an intake beat me... its just slow at 7... it feels juicy at 10.... it holds steady and does not knock... Im not running any more than stock boost without doing supporting mods.... I used to have the same 2.3 focus hatch that my boy has and I KNOW that a turbo 200 hp car should kick that focus' shi+ loose...

I heard that the reason I was going to get knock is because of the ignition map advancing rapidly, which will cause knock with the 9:1 CR and 8+psi... Why cant I use higher octane gas to fight against the knock if this is true? remember, I said that I had no knock (I used my buddies scanner to read it while I was driving; twas a Snap-On) at 10 psi and it felt great.

I know that the stock fuel system can handle 10 psi because, if I am not mistaken, stock psi is ~12... fuel supply should not be an issue... Is there anything else I should look out for?

 

[JayRolla]

Stock psi on a 1g is more like 7-9psi. The reason you would get more knock is because of the higher compression with the boost. Timing wont advance more because of higher compression.

There must still be a problem if the car was running so bad at 7psi, because with stock fuel it should have ran strong and a little better with the n/a pistons. I know of a few people in my town that have ran those pistons with good numbers, the problem comes when you start to up the boost.

Next thing I would get is a logger so you can monitor at all times. Make sure you do a good 3rd gear or even 4th gear run to make sure shes not knocking. A run in second wont cut it.

 

[DJYoshaBYD]

I Know.... I did my runs in 3rd.... This is my first experience with these cars.... The first one I was ever in was a 12.3.... so I dont know what to think of this car at 7 psi... it may be stock, and should be solid at 7 psi, but its slow as all hell to me... I had a built motor in it that I rebuilt and at 7 psi it was still just as wack as the swaped NA motor I put in, so I Know its not the motor... Maybe im just spoiled because I havent been in the 15's in a long time.... But my friends focus whooped me up from a roll, which should not have happened.... there is no way that 7 psi 200 HP... Like I said before, im not worried about fuel because Im not going above 12 psi yet... that is not the issue... I just dont understand why im not getting knock at 10 with this setup when I was told that it will knock because of the ignition... and it feels fast and smooth at 10... no stuttering.. no loss of power until real top rpm's... and no knock...

 

[freshlane]

aren't you supposed to run 93oct?

 

[DJYoshaBYD]

we, in California, dont have the fantastic luxury of 93 octane at every pump... 91 and .8 octane booster is the best we do with out going to 76 Gas and getting the 100 octane for 5 bucks a gallon....

 

[freshlane]

oh ok, ...kinda off topic but most turbo cars in Cali use 91?

ps. the information you may have heard may have been for a stock N/A 4g63. What you heard was similar to what i heard when I was planning on doing my N/A to Turbo conversion.

 

[DJYoshaBYD]

all we have is 91... if you are lucky, there are a FEW places that have 92

I basically did that swap... I have a 1g AWD, but I put a JDM NA 4g63 in... I swapped everything over, and it runs great... the only difference internally for those NA motors are the exhaust cam and the higher compression pistons.. same rods.. same crank... etc...

 

[freshlane]

what did you swap into the NA from the AWD?

 

[JayRolla]

You have some type of problem. Should still be strong at 7psi. I would boost leak test it, check compression, check timing. Make sure all plugs and wires are new. The only reason you would get knock is because of your fuel. With higher compression pistons you need more fuel to help with the knock. All cars are different and if you are getting no knock at 10psi than your fine. You shoulnt get more knock by lowering the boost though.

 

[DJYoshaBYD]

ok.. i mean, its cute at 7 psi... when I sat in the passenger seat and had my boy drive it hard, it did kind of pull, but not really... not 200hp pull... but then again, im used to the pull of a mazdaspeed6, a supercharged Iroc-Z, and a honda that weighed nothing and had 210 hp... I really really really think that im just spoiled and used to cars that pull harder...

Plugs are good, just did the timing, rechecked cam timing, and it did the same thing at 7 psi with a BRAND NEW motor as it did with a NA 6bolt that is used a bit... these cars just suck at 7 psi...

And i could've sworn I saw that 1g's boost at ~12 psi

 

[JayRolla]

When my brothers car had a 13g and was all stock there is no way a focus could take it. Not even a SVT unless it had some type of forced induction.

10psi is not much different than at 7psi and shouldnt feel to much different. Sounds like maybe your just not used to a stock dsm. I was in my buddys stock GVR4 and was very unimpressed.

 

[DJYoshaBYD]

My boy had an svt focus, and at 7 psi the only way I could even have the slightest chance of beating him is the AWD... from a roll, I know he would eat my 1g, but now with it up to 10, it feels pretty juicy and there is no way in hell an SVT would keep up now.... I had a friend that drove a stock one before and he said they were slow but had some nip then he drove mine and said it felt almost the same....

Maybe I have the CAS 180* out or I need to change the ignition coil pack to the one that came on the turbo?