r8rs4lf Posted June 27, 2004 Report Share Posted June 27, 2004 Very good info there guys! I am curious as to the max boost of the Radix SC. What I mean is not taking internal mods into consideration, what would the max (limit) boost the Radix would put out? I know there are different size pulleys, which one creates the most boost and exactly how much? If they do put out about the same amount of boost, it would seem like the Radix is a little better in the pocketbook as well as in ease of installation and being user freindly. I don't plan on tearing up my motor to lower the compression ratio, so as of right now, it seems like the Radix is a better choice for me. I will keep my eye on this STS turbo thread until I have the cash in hand for a purchase which should be in about 2 weeks. Late- Alex Link to comment Share on other sites More sharing options...
BenKey Posted June 28, 2004 Report Share Posted June 28, 2004 Very good info there guys! I am curious as to the max boost of the Radix SC. What I mean is not taking internal mods into consideration, what would the max (limit) boost the Radix would put out? I know there are different size pulleys, which one creates the most boost and exactly how much? If they do put out about the same amount of boost, it would seem like the Radix is a little better in the pocketbook as well as in ease of installation and being user freindly. I don't plan on tearing up my motor to lower the compression ratio, so as of right now, it seems like the Radix is a better choice for me. I will keep my eye on this STS turbo thread until I have the cash in hand for a purchase which should be in about 2 weeks. Late- Alex Alex, Max boost I think is 12. Ten can come pretty easily, but it wouldn't be something I was doing all that often with the stock CR of 10:1. A Radix also, can benefit from an Alcohol injection system, just like the turbo guys are doing. More boost usually equals more chance for knock retard (KR). When you start getting that KR at your max boost, you have to back off on timing. With a Radix, 9lbs of boost, alcohol injection and some custom tuning, you'd have a kickass system. Alcohol injection could allow you to run more timing per the 9lbs of boost. Same thing I think ssblackss is doing. It cools things down to allow for the extra timing, or more boost. The custom tuning, using logged run data could help you max out your timing. Personally I like the idea of N2O and the Radix. If you saw the thread about the two together, it would be awesome. He ran a mid 12sec. You get a double effect. The nitrous itself + the cooled intake air temps. You would get the same for any system, but since the Radix produces so much heat, it's appears to be an incredible difference. I believe PCMFORLESS posted a while back that a 35-shot was about 70hp to the wheels on a vehicle he had on the dyno. We'll maybe see in KS, but I believe that both systems with 8lbs of boost and similar mods, with a difference in torque converter being the major factor, will be damn close in a 1/4 mile. None of the top times on the track times for the Radix have a higher stall converter. I'm selling my Radix, if you're interested. Link to comment Share on other sites More sharing options...
MustBBrent Posted June 28, 2004 Author Report Share Posted June 28, 2004 Ok, here is an update!!! Holy BAT SH!$ Batman. I got to actually get on it several good times today. This is what I am seeing. The GT40 does almost 8psi in 1st, then 9.5psi in 2nd, and over 10psi in 3rd. The tell tale peak button on the autometer gauge shows 11.5psi max hit twice today in 3rd and the warning light I put on at 9psi comes on anytime I stand on it and the tranny shifts into 3rd. This is with the GT40 and a 38mm TiAL wastegate, so I am certain the turbo is too big (at least for the wastegate) and that I am getting boost creep as I have the .6bar which should be about 8-9psi only. Next thing I found out. Turbos like LOAD. I made a mistake this evening of hitting the tow/haul mode switch while messing around with some other stuff just before driving off. (side note: in my tuning, the difference is this... Normal, I don't lock the TCC until I am at whatever speed I am going to, and I unlock it anytime I step on the gas with any kind of decent change in TPS. In Tow/Haul mode, I keep it locked up all the time in 2nd 3rd and 4th. I even lock it at WOT in Tow/Haul mode.) So, I thought, wow, that turbo is behaving so much better than it was.. Not that it was bad, just wasn't as big a difference as I expected until you WOT it. Then I looked at the Tow Haul light on, and remembered what Rusty at the converter shop told me. I built this converter with kevlar so you can lock it up and load that turbo all the time. The grand nationals they do, get locked up to make the big times down the track. What a difference. This is the way, that truck should run. I may go down to the GT67 (GT37 compressor with T04 turbine) as the boost creep and 11.5psi in 3rd scares me a bit. BTW, watching the incoming air temp gauge, I get a consistent 115* when not on it, when I put it over 1psi, it goes up to 130 or so and quickly drops when you let off... and when you from a stop floor it and hold it over 100, I get upwards of 165*-170* and it quickly drops to under 150* when I let off then slowly goes back to 115*... and it was 88 outside and muggy all day by the rear view mirror. Hope this helps you guys. Noone has wanted to race me, but boy do I get a lot of lookers and stares. The turbo is loud outside the truck, but not bad inside the cab. Link to comment Share on other sites More sharing options...
BenKey Posted June 28, 2004 Report Share Posted June 28, 2004 Your inlet temps sound about like mine, or maybe even a little higher. Did you monitor for knock? How much is your timing set at? Link to comment Share on other sites More sharing options...
MustBBrent Posted June 28, 2004 Author Report Share Posted June 28, 2004 Your inlet temps sound about like mine, or maybe even a little higher. Did you monitor for knock? How much is your timing set at? 0 knock so far. But now that the turbo is on, my LTFTs went from -.5 and -1 to -5 and -6 Link to comment Share on other sites More sharing options...
vette dude Posted June 28, 2004 Report Share Posted June 28, 2004 brent have u thought about just porting the wastegate? that has worked for a ton of people on th WRX STi who would get boost creap after a down pipe change... Link to comment Share on other sites More sharing options...
zippy Posted June 28, 2004 Report Share Posted June 28, 2004 sounds like you're having fun with your turbo so far. turbo's are based on load to make boost, but a supercharger is pretty much the same just not as touchy about it. any engine that makes that much torque accross the band which becomes linear will run stronger with the tcc locked up. on the other hand like with the gn guys, locking up the tcc under w.o.t. will kill parts as it goes. Link to comment Share on other sites More sharing options...
BenKey Posted June 28, 2004 Report Share Posted June 28, 2004 Your inlet temps sound about like mine, or maybe even a little higher. Did you monitor for knock? How much is your timing set at? 0 knock so far. But now that the turbo is on, my LTFTs went from -.5 and -1 to -5 and -6 How much timing are you getting out of it under WOT, or have you even done much tuning yet? Allen tune you? Link to comment Share on other sites More sharing options...
zippy Posted June 28, 2004 Report Share Posted June 28, 2004 brent have u thought about just porting the wastegate? that has worked for a ton of people on th WRX STi who would get boost creap after a down pipe change... most boosted applications get more boost in higher gears than in the lower. Link to comment Share on other sites More sharing options...
vette dude Posted June 28, 2004 Report Share Posted June 28, 2004 isn't boost crep, when the boost continues to build after you let off the throttle? or , when the boost bvuilds above maximum set boost due to the inefectiveness of the waste gate? Link to comment Share on other sites More sharing options...
MustBBrent Posted June 29, 2004 Author Report Share Posted June 29, 2004 isn't boost crep, when the boost continues to build after you let off the throttle? or , when the boost bvuilds above maximum set boost due to the inefectiveness of the waste gate? yessir. I have a 9psi or .6bar spring. When I get 11 in 3rd gear... that's too much. Link to comment Share on other sites More sharing options...
vette dude Posted June 29, 2004 Report Share Posted June 29, 2004 have u thought about fabing up an external waste gate? That would fix it forever, as you could get a waste gate as large as you would like then.. Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted June 29, 2004 Report Share Posted June 29, 2004 The kit comes with a TiAL wastegate. Link to comment Share on other sites More sharing options...
ssblackss Posted June 29, 2004 Report Share Posted June 29, 2004 Correct Erik, It does come with an external waste gate 38mm one at that. and that is adjustable by changing a set poundage spring this denotes your boost level Jonathan Link to comment Share on other sites More sharing options...
MustBBrent Posted June 29, 2004 Author Report Share Posted June 29, 2004 Correct Erik, It does come with an external waste gate 38mm one at that. and that is adjustable by changing a set poundage spring this denotes your boost level Jonathan Unless the gang busters Turbo charger you get is TOO big and wants to make 20+ PSI and the 38mm Wastegate can't keep up. Then you get boost creep... Or you could get a smaller turbo or a bigger wastegate. I am heading down to a smaller turbo. Link to comment Share on other sites More sharing options...
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