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Enter The Supra
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Discussion Starter #1
Hey guys, I decided to post this email from yesterday in here to see what other guys are running in similar applications. Anyone with a valid response please reply. Thanks!

Joe,

Ok, so in regards to the spring rating of 11.4-17.1 psi... does that mean it will be optimal to run my car at those boost levels because that's what the spring can best control and maintain boost at? I've never run lower than 92 octane gas (rated at the pump) in my Supra, and typically only run 93 octane sunoco. I figure 92-93 octane is good for about 17-18 psi max which is probably where I'll run it at most of the time. At higher boost levels, I'll be running 115 octane gas. I apologize for not knowing which scale that is going by, but it should be good for about 30 psi of boost. Which spring would you recommend? This car is a daily driver first and foremost, I don't know how often I will be turning it up to 30 psi, mainly because I don't have a roll cage in my car and will be kicked out of the track promptly after making a run at that level. I'd like whatever would give me the best combination I'm looking for. I also read in the thread that these guys are using 2 springs; a base rate one and one for higher boost levels. Can I utilize a combination like that, or is that for another type like a Tial?
Thanks,
Bob
 

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SupraForums Manufacturer/Tuner
Joined
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1,002 Posts
Hey guys, I decided to post this email from yesterday in here to see what other guys are running in similar applications. Anyone with a valid response please reply. Thanks!

Joe,

Ok, so in regards to the spring rating of 11.4-17.1 psi... does that mean it will be optimal to run my car at those boost levels because that's what the spring can best control and maintain boost at? I've never run lower than 92 octane gas (rated at the pump) in my Supra, and typically only run 93 octane sunoco. I figure 92-93 octane is good for about 17-18 psi max which is probably where I'll run it at most of the time. At higher boost levels, I'll be running 115 octane gas. I apologize for not knowing which scale that is going by, but it should be good for about 30 psi of boost. Which spring would you recommend? This car is a daily driver first and foremost, I don't know how often I will be turning it up to 30 psi, mainly because I don't have a roll cage in my car and will be kicked out of the track promptly after making a run at that level. I'd like whatever would give me the best combination I'm looking for. I also read in the thread that these guys are using 2 springs; a base rate one and one for higher boost levels. Can I utilize a combination like that, or is that for another type like a Tial?
Thanks,
Bob
Bob, the base wastegate spring supplied with the HKS wastegate is simply a base range that you can do without an electronic boost controller (right out of the box). The range of 11-17 psi is determined by how far in the adjustment nut is turned on the wastegate to compress the WG spring harder. But with an EBC installed, you should be able to take that base spring and run 28-32 psi on race fuel. There really isnt any need to have two different springs, since the WG spring determines the minimum boost you can run also. In other words, if you remove the 11-17 psi spring and install the 30 psi spring, you cannot go under 30 psi but can go higher. Best to keep the 11-17 psi spring in place and use an EBC to gain more boost for race fuel settings. Of course, there is alot more to consider when running 30 psi, such as proper fueling, engine management, and tuning for proper A/F ratios. Joe can elaborate on this further via email.

Thanks,
JH
 

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Enter The Supra
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Discussion Starter #3
Thanks Jarrett. That pretty much answered my question. I am controlling boost using the HKS EVC6, I just read through some threads of guys not being able to maintain high boost levels (I believe they said they were running an EBC, can't find it to check again without the search function though), and the culprit according to them was the wastegate spring. Thanks again.
 
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