Have over 800 miles on my pump gas turbo and have weaned it from 50-50 pump-av to 1 gallon av to a tank full and have not gone into limp mode (detonation) and sled runs better without avgas. This is with a ebc set at 8 lbs at 5000 and egt's running at 1200-1210 at wot. This is also on a 09 m8, is this what others have seen????
Av Gas Good or Bad for Performance
- Thread starter TREE_MAGNET_777
- Start date
If you left the boost at the same level, and then pulled octane to a level more inline with what the sled needed, then it would make sense that the sled would run better. I would guess this is because of running less octane though, not specifically because of decreasing AV.
makes sence i guess. I just ran avgas for peace of mind and was told it would not make that much of a noticable differance in power but on my sled it was noticable. Thanks for the reply.
I think that's likely a good example for people who are adding way more than needed (I don't mean 1 gal or so, to be safe) of what is to be gained by being closer to their proper octane/ det limit.
The thing that gets me is how different it is from one sled to the next. I went from the least sensitive sled I've ever run, to the most sensitive sled, with the same kit. I guess unless you go find the limit, you'll never know where it's at.
fuel
I like this thread alot because when we raced in Fernie,BC,,you guys should have the seen the conconctions the different racers were brewin up...full c12, full av, 91 plus av etc..nobody was using 87...some guys couldnt build enough boost to save their lives....my cousin was hoping for 24 lbs and could only get 16 on his nytro and ended up ripping his boost controller right off for the final. Brother in-law cracked his manifold and blew his boost lines off.We figure the manifold gets too hot and too cold too fast so they need to be wrapped and sprayed to cool slower.Theres a video on youtube under fernie snow drags which shows some of the races..fuelling is in art in itself.. i agree the magic number variates engine to engine..theres probably more factors like elevation,barometric pressure,spark plugs etc...not sure of em all..
I like this thread alot because when we raced in Fernie,BC,,you guys should have the seen the conconctions the different racers were brewin up...full c12, full av, 91 plus av etc..nobody was using 87...some guys couldnt build enough boost to save their lives....my cousin was hoping for 24 lbs and could only get 16 on his nytro and ended up ripping his boost controller right off for the final. Brother in-law cracked his manifold and blew his boost lines off.We figure the manifold gets too hot and too cold too fast so they need to be wrapped and sprayed to cool slower.Theres a video on youtube under fernie snow drags which shows some of the races..fuelling is in art in itself.. i agree the magic number variates engine to engine..theres probably more factors like elevation,barometric pressure,spark plugs etc...not sure of em all..
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wasatchcomm
Well-known member
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Sparx
Active member
I went through alot of learning with all these issues this season with my 2010 OVS Tial M8 setup. 680miles and not one issue with the motor, reeds, turbo all season long. Best most reliable sled I've ever rode.
My biggest issue was with compressor discharge temp after the 2nd hard pull over 12lbs boost. Without an intercooler I wouldn't recommend running hard over 10lbs boost since no matter the fuel, I'll detonate on my Tial setup.
[http://www.youtube.com/watch?v=vsqSMXaT63w
Going to Propane and Intercooler next year, going to run 14-20lbs boost
- 10-12lbs boost max 6-9000ft on straight AV, 15lbs and you'll be detonating in a heartbeat on first pull
- 1/2 Chevron 94, 1/2 TrackTek 111 Ran great at 9lbs boost
- 1/2 Tracktek 118, 1/2 100LL(AV gas) as well as 1/2 Tracktek 111 Ran great, waste of octane up to 15lbs
- Straight 114 @ 1250ft elevation, 9lbs boost, no problems, ran hard
- Straight Tracktek 111 up to 14lbs boost, ran great everywhere
- Straight AV at 2000ft and 2ft deep on it hard will detonate at 9lbs boost or more, take it easy on the climb up the hill
My biggest issue was with compressor discharge temp after the 2nd hard pull over 12lbs boost. Without an intercooler I wouldn't recommend running hard over 10lbs boost since no matter the fuel, I'll detonate on my Tial setup.
[http://www.youtube.com/watch?v=vsqSMXaT63w
Going to Propane and Intercooler next year, going to run 14-20lbs boost
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The only way to compare would take the same amount of total octane using race gas vs av gas and see how it runs. You where simply running to much octane. I have seen bd kits on 09's run 8lbs on straight pump. Until you hit that det code you will never know, its not life or death if you hit it either just pay attention and adjust boost to not do it consistently, det 21 is no biggy, det 23 is the one to worry about, I have seen 21 lots of times and 23 a few times, Pistons still look great.
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Sparx
Active member
I've ran many tanks straight race, vs many tanks straight AV, not sure what your getting at? Can't compare a BD kit to my Tial sorry, just no comparison. I've rode a BD Pro RMK at 10lbs and it was nothing like my 2010 M8 @ 10lbs with the Tial setup, would have to run like 13lbs to be close on that setup. Elevation matters more than boost levels in what you can run for fuel IMO.
In the end as I said, I was hitting DET 21 due to compressor discharge temp more than overboosting for fuel quality. Once you go to 14lbs boost on my setup, you scorch your hands on my intake pipe, night and day compared to 10lbs.
When I set off DET 21 at 2000ft on straight AV gas at 10lbs boost it kinda let me know how much I was pushing the limits with AV, so safe at +6000ft, but take it easy up the trail up to 10lbs boost, maybe 12 if your feeling brave. Maybe even 14lbs if you have an intercooler/fan setup. But now we're getting into speculation as I haven't been there yet. The rest, I've proven first hand with many people to see it first hand and show the codes too. It sounds like your hitting the rev limiter even before the code kicks in.
The way my sled works with this OVS setup it seems impossible to blow it up octane wise with the DET sensor working so consistantly. If I had a boosted M1000 I'd probably have went through 5 motors this season. Thanks to Travis and Garr for steering me towards the race gas M8 setup!
so if I may ask....what is the differance between 21 and 23??? other than two numbers
Thanks for the info
Thanks for the infofuel
just wondering what direct role fuel plays in compressor discharge temps...
just wondering what direct role fuel plays in compressor discharge temps...
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realbass
Well-known member
Your sleds ran differently not because of the fact that you have had a different turbo kits.
It ran differently because it's different sleds, different ignition, different CR Ratio, etc. I think.
AC '09 M8 and AC M8 '10 on the same turbo kit running differently on the same boost. Because they have different engines with different settings.
so if I may ask....what is the differance between 21 and 23??? other than two numbers
21 - code of deto
23 - code of knock sensor failure
sometimes I saw a broken knock sensor which is always a showed error 21
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Sparx
Active member
Pretty much none, it never really made a difference if I had a 118/111 mix or straight Av. It made more of a difference running a Mesh hood simply for the fact I could get an extra pull in or two before heating up the discharge temps more. In the end, I could run straight 118 and still trip on Deto because of discharge temps...
Confirmed this with Garr(OVS) that there's no way around it except to run an intercooler. I don't know how people can run more boost on the twisted kits without an intercooler? Some guys told me they couldn't on their M8 Twisted kit, yet I hear of guys on Snowest claiming to run up to 20lbs??? Seems illogical with such a short discharge tube, even if you could, dunno how the reeds would last 5 pulls like that with the kinda temps you'd get coming into the intake at that load??? I got it over 15lbs a couple times and instantly was bouncing off Deto bad. Can't hear it well in this vid, but the blurbble actually almost stalled my sled mid way through the climb when it mattered most to the point it almost died completely!
http://www.youtube.com/watch?v=_7KjJnS16BE
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Sparx
Active member
Funny, I bought the Tial more because I wanted to run Propane down the road and that's the setup they were using in their kits. They mentioned a power difference with the Tial setup and I left it to be seen on the hill.
It's proven me since I have friends who've ridden the same exact sled (Pro RMK) and a '09 M8 with both pump gas BD kits at 10lbs boost running straight AV. Irronically they say the same thing that either machine on the trip before ours that they were swapping marks all day and he even personally couldn't see a difference. Yet he says my sled at 10lbs is a whole different sled, go figure...
So your basically saying it's most likely that my 2010 M8 with a 2009 head feels so much better not because it's a RG kit or Tial, but rather because of a 4lb lighter crank and HO pipe, different mapping for timing? I find that hard to believe, I think the '09 and '10 sleds aren't much different power wise at the same boost levels once under pressure...
SPARX, on our 09, we can do back to back pulls at 15 psi (2 injectors) with no problems on mostly 91 with 2.5 gal of 114 or 1116 mixed in, NEVER had det with that sled (wish my 11 was like that) There's just so many variables when it comes to what you can run for fuel & boost...
m1
i take it the 1000s dont have a knocksensor..
i take it the 1000s dont have a knocksensor..
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Sparx
Active member
Sure no problem, but please whatever you do, please post the elevation as that matters quite a bit IMO. I'm quite aware you normally run up to 10,000ft? I'm rarely up past 7000ft when doing hard pulls. I'm sure I could get away with 15lbs no problem myself at 10,000ft. I do have the dual injectors. Have you touched your intake pipe after a hard pull? How hot was it?
I think there are alot of variables, but when you put elevation into the equation it's almost like simple math pretty much based on HP. The main difference IMO is the efficiency of your compressor and that's where supposedly the Tial setup makes all the difference in the world and I, personally see a big difference comparing my sled at 10lbs at the same elevation as a boondocker kit at 10lbs, same fuel. It's too bad we can't just go out tomorrow to share our experiences first hand, I'm sure we'd have alot to learn from eachother!!!
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Sparx
Active member
No knock sensors on the 1000, Garr was telling me there's a distinguished sound you get used to when you creep up on detonation on them to tell when your pushing the limits. No, that sound ain't Kaboom either!
It's like a rattly vibration buzzing sound I believe he was telling me about. Sure would love to try a TM1200 sled one day. The RG TM8 is fun, but I want something that scares me silly on the first run! 
