18lbs of boost

[Lou86]

Currently on the car, 42.5lb injectors, 255 warlbro, hotwire, ttchip, adj fpr. stock down pipe no cats, running shell 93 octane.fuel pressure 43 line off. aside from that plugs and wires are new, no vac leaks, exhaust leak is present at turbo to manifold gasket is on order.

can I achieve running this level of boost with what I have safely. from reading previous i see a couple of people able to run this level with no knock, the difference is bigger turbo or alchy...

from the run i had yesterday the SM read 3.4 on the knock @18 psi weather temp yesterday was in the upper 80's

today i ran 18lbs and th SM read 2.0 knock only difference today is that i increased the fuel pressure to 45 line off and the temperature today in sunny south florida is in the lower 70's


also knock is only shown after i let off the gas, not actually under load. Im not opposed to running alchy at all and will order the kit when i recover some funds just want to know if i can do with out? and what adjustments need to be looked at or made?

 

[TurboTnZ06]

Just like tuning with alky, drop the boost down to say 16 psi and see if the knock persists. 18 psi is pushing it on the junk gas we have (E10)

 

[Blazer406]

stock intercooler?

what timing?

I would cut it down til no knock..... not real sure what to make of the no knock until you let off..... you got something hitting on the frame upon let off?

broke motor mounts?

 

[Lou86]

pass side motor mount does need to be replaced, intercooler is stock, and the TT chip was programed with the upgrades i have so far in mind for 16-18lbs of boost.

at 16psi theres no knock.

 

[Lou86]

is it worth getting the urethane motor mounts or will the stock ones suffice?

 

[mtbraun]

is it worth getting the urethane motor mounts or will the stock ones suffice?

Depends on your goals. Stock ones are good for quite a ways, I beleive. I replaced my originals with stock replacements and couldn't get rid of the flex-associated downpipe contact, so went with the HR mounts. Rock solid now, no DP contact. Only downside is now I have more interior rattling than before.

 

[Lou86]

Just looking to go fast on the street. I just ordered the stock ones at $10 a pop why not? Right??

Oh and I need to replace the trans mount, that I have.

 

[Blazer406]

I modified a new drivers side motor mount with a short chain like 3 links and welded the chain between the two halves..... there is a thread somewhere here with pics I started.... anyway... in theory..... the motor mount under hard acceleration tries to separate and usually breaks the rubber quickly on a car making anything over stock HP and sticky tires...... with my mount.... I get the benefits of the stock rubber mounting and as it tries to separate under hard acceleration.... the chain links tighten up and keep the drivers side from separating any further.

Don't know if this helps you or not.... but it is what I am trying..... will know more results of my experiment in the months to come....

 

[kidglok]

i bet the dp is hitting the control arm when you let off the gas

 

[~JM~]

....at 16psi theres no knock.

That's what I have found so far on my car with straight 92 octane.

~JM~

 

[Lou86]

Blazer406, sounds like a good tip thanks man. Hopefully its just the mount, I'm alot confused on how to tune the car other than playing with fuel press and boost

 

[INEEDAGN]

The problem you will find with running max boost on pump gas, is that max boost will vary with atmospheric conditions and the exact fuel you are running that day. I "can" do 18 psi with 0 knock, when everything lines up in my favor. Up until recently I had a 17 psi spring in the external gate so I didn't have much choice. I recently swapped in a 13-14 psi spring and turned it up to 15-16 and am happy with it. If you aren't monitoring knock at ALL times you won't want to leave it at 18 with stock type stuff. Good intercooler helps, ability to fine tune other parameters such as WOT fueling and timing will help you as well.

 

[HelloBozos]

18psi is safe, most have to run external wastegate( bleed off valve) to go higher.I run 22psi with a gt71,72inj, safly,93/alky

Put a Urethane motor mount on drivers side,Works Great ,or RJC racing has the rear one

Put a bronze bushing in top rear Passenger upper A-Arm mount (won't melt)

Enjoy!

 

[Lou86]

Well..... Just put a hole behind the block. Fuuuuudge!!!! Oh well atleast this gives me an excuse to rebuild from the ground up! What brand of pistons can any one recommend??

 

[Lou86]

Here's the pic

 

[Blazer406]

?? What happened there?

 

[Lou86]

dont know. I made a sharp left to get onto an on ramp for 95south then i heard a rattle/clacking and she died... towed her back to the shop and found the hole. I wasnt in boost and was just starting to accelerate after the turn as it happened...

 

[Lou86]

my guess is that the chain broke and lashed out on the cover

 

[Blazer406]

there is your knock.....

 

[Lou86]

you can say that again! oh well live and learn.. guess it leaned out on that sharp left, fuel level was at 1/4 tank and you know these fuel senders are not that accurate.