My first question is this, Im boosting my car under 300 whp, using a greddy 18g. Will I need to upgrade my main bolts or can I use the stock ones? I don't mean head bolts bc those are being upgraded but the main bolts.

Second question is this. I recently purchased an internal waste gate from ATP for my 18g it was listed as a 14psi wastegate. I'll try to attach the link at the bottom. But anyways I got it with the assumption that I could have a wider range to tune from. I wanted to do 6 psi for daily driving and up it to 14-16 for other. So the question is this, can I do that with this internal wastegate or will it not open for 6psi even if tuned to do that. Not sure if that made sense but I'm Afraid that it's not gonna open for anything less than 14psi. Is this true or not?http://www.atpturbo.com/mm5/merchant...egory_Code=WGT

 

It would help to know what engine you're using...although having said that, I have never heard of anyone upgrading main bolts regardless of power level. For your goals, you will be fine.

As for the internal wastegate, you can only go as low as the wastegate spring allows. In this case, your 14psi wastegate means you will be able to run 14+psi but no less. If you want the ability to vary your boost level, keep the stock WG actuator and buy a boost controller. Your fears about the WG are correct...

 

I guess I did forget that lol, the engine is a b18b1. The whole bottom end is upgraded with the exception of the crank and main bolts, but if the stock bolts are fine then I'll keep them. Thanks

 

I believe I attempted to explain this. once you get the upgraded actuator and rod to the 14psi one, you CANNOT GO BACK DOWN TO 6psi... PERIOD 14psi is the minimum on that wastegate actuator to use. If you're so worried about some sort of boost by gear, forget it.. use your brain, your foot, and good judgement, and you're fine. 1st or 2nd gear wouldn't helpyou anyway at 6psi.

 

You have a built LS but you're going to run less than 10psi on an 18G? That hardly seems worth it...

 

Well that wasn't my goal. The problem is, this car is a daily driver and will see Ohio winters and snow. With that being said, I don't want to run 14 psi as my normal crushing boost. I built the bottom hoping to be able to boost close to 300 with the 18g which will take plenty of boost from it. But I want to be able to tune down to a good driving boost for winters and regular driving. So that's why I have my delema. The stock will only hit 12 psi max with boost controller. So what can I do? Any suggestions or different actuators?

 

I would just run an electronic boost controller and then have 2 tunes for the car. As others stated a wastegate spring is just that, whatever the spring is set for is what it will open at.

If you question was that your wastegate was set for 10PSI yet you wanted to run 18PSI out of the turbo, then that would or could be a different answer. In a turbo system you have intake PSI and then an exhaust PSI, both systems are independent yet needed to make sure nothing bad happens. This goes for those that do not run a BOV and think all is fine.

 

Well I am planning on running an electronic boost controller and tune it but the problem is, the stock actuator is good from 6-12 psi on a boost controller. I wanna keep the low end for daily but I want to go higher for fun riding. But I can't find an actuator that has a larger range while still keeping the 6-8 psi range for daily driving

 

You won't. unfortunately, no actuator is avaiable with that much of a range. You would have the same difficulty even if you wen external. 6-18psi is too much for one spring to handle regardless of the boost controller. The pressure will either drop back down after a brief spike, or your minimum will be high.

Even in the colder winter days, due to the air density increase, you'll be hard pressed to be able to hold even 6psi without proper boost control. you'll go to about 8-9 depending upon the day.

Time for a winter beater.

 

Bingo!

I would assume, but have not had time that even if you have less PSI because of the cold your able to achieve more HP because the air is colder and denser, correct? I am not speaking in terms of 10HP, maybe a few because of that, no?

 

Well not what I wanted to hear but it is the way it is. Thanks everyone for the feedback. I'll look into other options for winter lol

 

It could be 10hp or 20hp depending upon the spike and the ability to control pressure. That's the trick; you don't really know..

 

That is what I thought. But is this in terms of 1-2 bar or does it not matter on the amount of pressure just on the temperature itself?