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radix power


zippy

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i don't think the issue here is bad information. at this point we're still working some of the problems out and i figured i'd post the information i had as i went. i haven't directly said that the 42's aren't big enough or that a walbro won't pump it. i have already in fact had a wideband on a truck with a 3.0 pulley that has only a 255 in tank and the stock radix 42's. it was very rich down low and slowly got closer as the rpm came up to what it needed to be. it also has a week timing curve yet. it's my theory so far that once we begin to get the tune on that truck where it needs to be we may run into a lack of fuel. this same truck doesn't drop fuel pressure with only the intank pump at this point. the truck we put the 2.8 pulley on was an 04'. the 04' has a different fuel pump system. we may be putting another stock pump back in (it began to give up on the last pass at the track) or a walbro 342 and buying a voltage increase mod to gain the volume. from there we'll do some wideband testing to determine what we find on the injector size theory. i haven't proven anything at this point or said for sure that these are deffinitly the issue. this is the reason the first post asks if anyone has actually ran theirs on the wideband. i was hoping to get a response from someone saying yes and that they had no problems at all. if you notice that isn't seeming to happen. part of the theory on the 42's does involve radix trucks only and only LQ9's. the LQ9 having the highest cfm requirement of any of the gen III trucks. the 42's in a radix use the stock fuel pressure regulator and do not increase the pressure as you would in something like a lightning or centrifugal (by means of an FMU). the lighting timing issue isn't even at all similarly related. two engines of different design will have a different timing curve. the car in my avatar we were able to run a peak of 28º of timing on pump gas and 30º of timing on a race fuel mix with 8psi and no intercooler. it had 8.8:1 compression and edelbrock heads. simply swapping the heads to fastburns (a gm performance part head) would have made more power with timing at around 22º to 24º. you say if you want to trap higher, add more fuel and timng and spin it faster. well, their are plenty of small pulley radix trucks on here and most on a mail order tune. i'm sure they have more fuel and more timing than came with the stock radix tune. the issue here is that even the one's self tuning only added as much timing as they could get away with without KR* and never bothered to check the actual afr. i'm hoping to gather enough information one way or another if the injectors are indead big enough for x" pulley's and if it's going to take more fuel pump than comes with the kit. my main basis for this is future information for the guys with a radix and looking to buy one. don't just go throwing pulley's on the truck to try to go faster. get it tuned first and with a wideband, not tuning by KR*.

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:withstupid: Awesome thread; please keep at this issue, it would be a huge breakthrough to authoritatively undertand why the Radix lays down on the top-end. And Zippy is right, you can't just raise the advance until the engine "pings" then back it off 2-3 degrees and call it good. And MNC5 is right, assuming that winding up beyond 5500-RPM will make more HP might well be a misassumption too. I am not trying to sound stupid here, but have you tested to see that you are meeting the basic octane requirement of the engine while under load (inaudible/undetectable knock)? Just trying to help eliminate another potential variable...

 

Mr. P. :)

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lol, the octane thing is a good point. this coming weekend we are hoping to have the 04' fixed and try some passes on 100 octane just to see how much gain there is. this would be a seperate tune for the different fuel of course.

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lol, the octane thing is a good point. this coming weekend we are hoping to have the 04' fixed and try some passes on 100 octane just to see how much gain there is. this would be a seperate tune for the different fuel of course.

Yeah it would be great to see what it takes to get the MPH up there (forgetting about the ET). I'm betting you already know this: Testing for Octane Requirements

 

Mr. P. :)

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I would not reccomend a Radix for a 402. It will not push enough air to provide much of a gain over that motor.

 

I had the Radix on a 427 and it made 7-8lbs of boost. It made even more boost with a broken valve spring :P (Some of you will know what I'm refering to..lol) As far as power goes it won't add as much as it would on a 347 for sure. But it will make tons of TQ and would be a worth while mod to a 402 hauling a heavy truck like the SS.

 

The Radix added about 60 peak flywheel HP to my 427. But it made that power early.. i.e. I think it hit 600 hp at 4400 and like 570lbs of TQ so low the dyno couldn't hold it down...

I'm running a 402 with a 228/234 .588/.598 cam and I'm only seeing 6lbs. of boost,I saw 618rwhp at 5900rpm,but was making 427rwhp by 4100rpm.I went with a bigger inline pump to remedy my fuel pressure loss.I had problems dynoing low rpms spinning my tires all the way through 2nd gear.

 

Those #'s are much stronger than mine were. I tried a few cams to but ended up with a 224/224 600 lift with Zero degrees of overlap. One of the others was a 230-236 on a 115 with about the same lift as yours and still wasn't close to 700hp. My heads were the equivelent of todays stage II's. I don't know what your doing but you definately were able to get more power out of the Radix than I was. Great Job.. :smash:

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lol, the octane thing is a good point. this coming weekend we are hoping to have the 04' fixed and try some passes on 100 octane just to see how much gain there is. this would be a seperate tune for the different fuel of course.

i dont have a wide band, but i do have two different tunes i run. a 91 octane for the street and a 100 octane for the track. i have had a kr problem since the day my radix was installed at magnuson. they wanted to keep the truck longer (over the weekend) to get a new timing set for it, but for the $100 + a night for a room down there i just had them send me a new tune. after that i got a custom tune from Allen. on my 91 octane tune he has pulled timing on it atleast 5 or 6 times do to "pinging at the shifts". my 100 octane tune has been fine, even spraying a 50 shot of nitrous on top of it... no kr, that i can hear.

i just wanted to let everyone know that ive been trying to figure out this kr thing for awhile now. Allen is a good tunner and a great guy. by no meens am i saying Allen is to blame here, he was just trying to help me fix the problem... about a total of 10 tunes later.

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lol, the octane thing is a good point. this coming weekend we are hoping to have the 04' fixed and try some passes on 100 octane just to see how much gain there is. this would be a seperate tune for the different fuel of course.

i dont have a wide band, but i do have two different tunes i run. a 91 octane for the street and a 100 octane for the track. i have had a kr problem since the day my radix was installed at magnuson. they wanted to keep the truck longer (over the weekend) to get a new timing set for it, but for the $100 + a night for a room down there i just had them send me a new tune. after that i got a custom tune from Allen. on my 91 octane tune he has pulled timing on it atleast 5 or 6 times do to "pinging at the shifts". my 100 octane tune has been fine, even spraying a 50 shot of nitrous on top of it... no kr, that i can hear.

i just wanted to let everyone know that ive been trying to figure out this kr thing for awhile now. Allen is a good tunner and a great guy. by no meens am i saying Allen is to blame here, he was just trying to help me fix the problem... about a total of 10 tunes later.

From what it sounds like, you have no logging software. If that is true, I just don't see how you can do a Radix and nitrous and feel like everything is good. Logging software won't net you any hp, but it one of the MOST important mods you can have. Especially for a combo like yours. The only real way to monitor KR is with the software, not your ears. I've seen as much as 8-10 degrees KR, but never heard a thing. Also the best way to maximize your setup.

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Well, you can't hear KR, KR is NOT knock and knock is what you hear. KR is the amount of timing thats being retarded to prevent Knock. Its when you max out the amount of KR allowed by the motor and computer that you run into the chance of actually have a knock count which is bad for your motor.

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Well, you can't hear KR, KR is NOT knock and knock is what you hear. KR is the amount of timing thats being retarded to prevent Knock. Its when you max out the amount of KR allowed by the motor and computer that you run into the chance of actually have a knock count which is bad for your motor.

That was kind of my point. KR you will never hear, but when it happens, it's definitely something to be concerned about - depending on the level of course. If it gets to the point of being heard (actual knock), then KR is probably already happened.

 

The main point is if any of you are trying to max out your setups, especially those that involve power adders or combinations of power adders, would abosolutely have to be insane to not monitor with some type of software, at least from time to time, what the hell is going on. That's just my opinion.

 

If you were doing mail order tunes, you could actually tell your tuner what you were seeing, or in the best situation, email him your logs for him to look at.

 

I will now step off of my soapbox. :happysad:

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Nope I think you're right BenKey. To be honest, too, I have always viewed my mail order tune as a conservative stopgap until I am through modding for a while and can go to Allen or someone else with experience for a wideband/dyno tune. I think a tune specific to the vehicle with readings on all pertinent variables is ultimately the only way to go to optimize performance on a particular setup. ;)

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Ben, you are right,. i have no logging software. :sigh: i was just trying to say that i have two different tunes for two different octane levels and it makes quit a difference. what you are saying about not knowing is true and this is one of the reasons i have taken the nitrous off. i would love to have a wideband set up, or at least done on my truck. i just dont know anyone who has a set up.

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