RG M8 Turbo Bottom End Response

[Gobig510]

I have a 2008 M8 Turbo, Race Gas, 13 pounds boost. 58/62 bdx lite gearing.

My question is, what kind of throttle response are you guys getting off the bottom end? My bottom end feels a little boggy compared to a stock m8. My brother has a speedworks set-up M8 piped and ported and he will jump like three sled lengths from the start. Once my turbo spools up I'll pass him with over 20mph his speed. I'm just wondering if you guys have been able to get better low-end than stock. I am thinking I might be running too rich on the bottom, cruising around blipping the throttle from quarter to half I run about 700 degrees egt... Should I lean her up a bit? Thanks

 

[TheBreeze]

1/4 to half cruising blipping throttle, i see high 900's low 1000's. My sled seems good in terms of throttle response, but my NA 08 M8, as well as my buddy's 2011 M8 feel stronger off the bottom.

 

[backcountryislife]

I don't see how you could ever see "better than stock" on the bottom... you're pushing a turbo with your exhaust whereas he's not pushing anything, but has a mod setup. We'll always be playing catchup on the bottom end.

That said, it should be darn close.

I usually see 900-950 in that range on my sled.

 

[knzee]

Before I bought my turbo last year our local cat dealer put together a boondocker pump gas setup. Me and another guy took our 1000's up for an afternoon to put some miles on the turbo and see how we like it. First hill we cam to was a little drag racing hill that was packed in like crazy. Now he flat told us he still had to figure out a little of the clutching but it was no race. The 1000's were all the way over the top before he got half way up the hill. I mean we jumped him by 5-6 sled lengths right out of the hole and the hill was too short for him to make it back up. I pretty much said you can keep the turbo I would rather have instant throttle response then big power on top any day for where we ride.
Then we went over to a pretty good hill with maybe 2' of fresh snow. This is were I got hooked on a turbo. It was a totally different race he would take us out of the hole and wheelie out the top while we were turning out.

That being said I picked up an 2010 with an OVS on it with their clutching and I have yet to get beat by an N/A 1000 or 800, cat, prolaris, or ski-doo on hard pack or deep powder. On the hard pack when we take off you can look down the line and who ever gets the best traction right out of the hole is usually ahead for a couple sled lenghts but then its lights out.

I really could not tell you where the sled runs for exhaust temp, it only has air/fuel gauge. I usually see 13-14 on high idle but if i feather it a bit while idling it drops to 12ish. Usually see 13's running down the trail and usually don't see it get too much over 12 on deep hill powder climbs. Sometimes I will start adjusting the my box up in different areas and ride it to see if it needs more fuel but it pretty much always needs adjusted back down afterwards becasue it is getting too much.

 

[kraftymike]

Try a set of MDS turbo weights. Tell Steve what, how, and where you ride. Then just do as the man says. Made a huge difference on my bottom end. Seems like a lot of money, but worth every penny.

 

[WyoBoy1000]

How much octane are you adding.

The 800 HO is a not comparable, its way better off the line. With the right clutching there should be some lag but then its over. Kinda like hitting the throttle, and wait 1/2 second and boom. But the more octane you run the more lag you have. I ran a tank of straight av gas at 13lbs and it was about 3x as bad on bottom end, figured out I could run 3-4gal or maybe less av gas to 91 octane and the bottom end was a lot better. But 91 octane on 7lbs was even better again. You could also add a high comp head and a timing control module and pick up some bottom end but I can't say for sure.

 

[wasatchcomm]

1/4 to half cruising blipping throttle, i see high 900's low 1000's. My sled seems good in terms of throttle response, but my NA 08 M8, as well as my buddy's 2011 M8 feel stronger off the bottom.

this is what is see as well for temps, at that range.

and yes the bottom end is not as strong as a stock sled.....

 

[wasatchcomm]

before you lean it out, check when your secondary injectors come on.
marke sure they are not coming on way to soon, could be all thats wrong...

 

[kraftymike]

before you lean it out, check when your secondary injectors come on.
marke sure they are not coming on way to soon, could be all thats wrong...

That is a good point. If my DC out drops bellow 90's I get a low end bog and have to adjust my cross-over numbers accordingly.

 

[wasatchcomm]

That is a good point. If my DC out drops bellow 90's I get a low end bog and have to adjust my cross-over numbers accordingly.

yes, its happened to me before as well..
i hate it when i fat finger the control box......

 

[Gobig510]

octane

I switched my octane a bit and noticed a huge difference. I was running straight 100ll at 10000 ft. Put in a few gallons of 91 and she perked up off the bottom. Still not as good as I'd like. Going to mess around with my fuel numbers a bit more.. thanks for the advice

 

[backcountryislife]

I switched my octane a bit and noticed a huge difference. I was running straight 100ll at 10000 ft. Put in a few gallons of 91 and she perked up off the bottom. Still not as good as I'd like. Going to mess around with my fuel numbers a bit more.. thanks for the advice

FYI, not sure where you ride, but for 13 psi I run 2 gal of 116 mixed in. That's about equal to 5-6 gallons of 100LL. (I ride 10k+)

 

[WyoBoy1000]

Who's kit are you running and what year/generation kit is it.

I was at 10000ft and 4gal of av at 12.5lbs never hit det sensor, with a 2871 turbo. If I remember right the 08 has a det sensor, I would try 4 av and turn it until det then back it off a bit, just pay attention and dont fry it.

 

[flatlandsledder]

Does the 2007 M8 have a det sensor?

I hope so.

 

[WyoBoy1000]

I hope so.

I don't think so, if you hear a rattling tingy noise, its bad det. sounds like something pinging off the pipe

 

[Vertical-Extreme]

I hope so.

Yes it does have the deto sensor. Same as the newer ones. There is 2 different codes. (can't remember them right now) but one is a "hey take it a little easier on me buddy" code. And the other is a "**** off or I am going to puke 2 balls of molten aluminum" code

 

[WyoBoy1000]

Yes it does have the deto sensor. Same as the newer ones. There is 2 different codes. (can't remember them right now) but one is a "hey take it a little easier on me buddy" code. And the other is a "**** off or I am going to puke 2 balls of molten aluminum" code

Code 21 and 23, 21 meh... 23 aw fawk, you sure the 07 had one, pretty sure the 08 was the first to have it. Little sensor in the center front of the head.

 

[flatlandsledder]

Yep

It has a little sensor in the front of the head. Good news for me.

 

[knzee]

Yes it does have the deto sensor. Same as the newer ones. There is 2 different codes. (can't remember them right now) but one is a "hey take it a little easier on me buddy" code. And the other is a "**** off or I am going to puke 2 balls of molten aluminum" code

LMAO....

 

[Gobig510]

when secondary injectors come on

How do you adjust when the secondaries come on? Can you do this on the boondockers box? I have all the rpm numbers zero, and am running psi low and psi high numbers a little leaner than what boondockers reccommends, but I didn't know you could adjust when the secondaries come on...