P1000 Jackal's P1000-5

[amc019]

I saw 59 mph (dash) on concrete. Wanna GPS check though.

Wonder why Jackal saw slower speeds with lighter tires?

According to my calculations, which could be wrong, coming from a 25.5 tire at 59mph, a 30" tire would be reading 69.4, and a 29" tire would be 67.1 mph. However, if the Speedo is calculated to 27" tires, then the 30" tire would be 66.6 mph and 29 would be 63.4.

At 51 mph, and 25.5" tires, a 30.5" tire is reading 61. With 27" tires going to 30.5, 57.6.

If only we could calculate our speedos to exact tire measurements, as I doubt they are accurate from the factory. Would be interesting to compare on stock tires with GPS.

 

[Admin]

 

[JACKAL]

Wonder why Jackal saw slower speeds with lighter tires?

According to my calculations, which could be wrong, coming from a 25.5 tire at 59mph, a 30" tire would be reading 69.4, and a 29" tire would be 67.1 mph. However, if the Speedo is calculated to 27" tires, then the 30" tire would be 66.6 mph and 29 would be 63.4.

At 51 mph, and 25.5" tires, a 30.5" tire is reading 61. With 27" tires going to 30.5, 57.6.

If only we could calculate our speedos to exact tire measurements, as I doubt they are accurate from the factory. Would be interesting to compare on stock tires with GPS.

No the tires were NOT lighter they were heavier by 16 pounds each on the front and 11 pounds each on the rear. You interpreted it bassackwards.

 

[Fullthrottle]

I saw 59 mph (dash) on concrete. Wanna GPS check though.

I would say speedometer will be way off.

 

[chadbo]

OK been discussing different tires with @joeymt33 explaining what I ran into vs. his 30" tires ending up only being 28" tall. As previously posted I experienced anomalies in 6th gear only at 51 mph in H or at 30 mph in L range running Roctane XD tires in 30x10x14 all the way around.

So tonight I get out my level and metal tape measure to verify what was the actual tire height. Just measured both the front and rear OEM tires with 14 PSI & Roctane XD at 10 PSI This was done with a level across the top of the tire at the highest point level and measured at bottom of level.

Honda 27" Bighorn 2 OEM Front 25.5" tall @ 14 PSI
Honda 27" Bighorn 2 OEM Rear 25.7" tall @ 14 PSI
STI Roctane XD 30x10x14 tire on 14x7 rim 30.25" @ 10 PSI

This explains how I gained 2.25 " of lift with the tires/wheels alone as they are 4.75" bigger in diameter than OEM, the OEM tires weight about 26 pounds in front and 32 pounds in rear. The Roctanes are just over 42 lbs. each. so with the nearly 5" diameter difference, and 54 pounds of increased un-sprung weight to spin up I am speculating it is causing issues in 6th gear in how the computer is sensing the load on the transmission. I mentioned previously that if you lightly let off it feels as if the clutch locks up and if you mash the gas pedal it feels like it starts to slip and then the engine starts to surge like an electronic cutoff as it if knows the transmission is under stress and limits the power output to prevent damaging anything.

At this point I am thinking of dropping to 28" tires instead of fighting these with forward A-arms. If anyone is interested in a set of Rocatne XD 30x10x14 on 6+1 offset 14/7 STI HD3 rims I would make someone a pretty good deal, they only have about 25 miles of driving on the road.

View attachment 9843 View attachment 9842

Well thanks for the heads up @JACKAL ... Wish it would've worked out you had to much leg work finding out just what you wanted for it not to

 

[Fullthrottle]

Same here with the Outback Max 30's... they shipped at 54# each but I don't figure to be running those speed +50 mph much. Having lowered the air pressures to 10 psi I haven't had any noticeable rubs. I'm gonna play with em a lil longer before I put the big tires to pasture. Although I'm thinking goin back to smaller rubber also to avoid tearing anything up. I'm not a member of the "if you ain't breaking stuff you a'int having fun" school of thought.

What are you running for a lift?

 

[Fullthrottle]

Is TOOLOUD experiencing any transmission hiccups with his 30 inch tires?

 

[amc019]

No the tires were NOT lighter they were heavier by 16 pounds each on the front and 11 pounds each on the rear. You interpreted it bassackwards.

I was meaning that the 30" Rocktane's are lighter than the 30" Outback Max, where you saw a top speed of 51, and tabasco junkie saw speeds of 59. I assume the speedos are all calculated the same from the factory, so it doesn't make sense that a tire (outback max) of the same height that weights 6 pounds heavier each than the rocktane would provide higher top speeds.

 

[JACKAL]

Well thanks for the heads up @JACKAL ... Wish it would've worked out you had to much leg work finding out just what you wanted for it not to

I think it will be OK got some good contacts with RMATV (where I got them) I believe they are going to swap me out with what I need no problems. Dropping to 28x10x14's they are only 2 lbs. heavier (37 lbs. ea.) than OEM rear tires and a full 2.7" taller at 28.3". This will solve my rubbing issue without spending $500 on forward A-arms.

 

[JACKAL]

I was meaning that the 30" Rocktane's are lighter than the 30" Outback Max, where you saw a top speed of 51, and tabasco junkie saw speeds of 59. I assume the speedos are all calculated the same from the factory, so it doesn't make sense that a tire (outback max) of the same height that weights 6 pounds heavier each than the rocktane would provide higher top speeds.

OK I misunderstood you bassackwards then

My issue isn't top speed it is getting over 5K RPM it WILL not do it in H or L range, put OEM tires n wheels back on redlines like no tomorrow, swapped back and forth 3 x on same day to make sure I wasn't losing my mind. So the speed is RPM limited.

 

[amc019]

OK I misunderstood you bassackwards then

My issue isn't top speed it getting over 5K RPM it WILL not do it in H or L range, put OEM tires n wheels back on redlines like no tomorrow, swapped back and forth 3 x on same day to make sure I wasn't losing my mind.

If you put it in manual mode, does it change anything? Can you stay in say 5th gear longer and reach max RPM? 6th gear?

 

[JACKAL]

If you put it in manual mode, does it change anything? Can you stay in say 5th gear longer and reach max RPM? 6th gear?

It will redline in every gear except 6th in manual mode. Meaning it hits the electronic rev limiter.

 

[amc019]

It will redline in every gear except 6th in manual mode.

Interesting, I am curious to see if others with 30's will chime in with some additional input. Unfortunately, I cant just run mine down the highway to find out.

 

[Fullthrottle]

Strange that won't redline in low range.In sixth.

 

[nbomar]

My 28" intimidators will still redline the engine and will run about 54 mph in 6th. They are probably close in weight to your 30" rocktanes.

 

[JACKAL]

Strange that won't redline in low range.In sixth.

Exactly I was like WTF BBQ I thought I had a mouse nest in my intake tube, didn't I checked everything out.

To quote another member word of the year, "That superwankeydyne transmission" and computer isn't liking some reading it is getting with that tire combo I ran.

 

[Fullthrottle]

Exactly I was like WTF BBQ I thought I had a mouse nest in my intake tube, didn't I checked everything out.

To quote another member word of the year, "That superwankeydyne transmission" and computer isn't liking some reading it is getting with that tire combo I ran.

You'll be going way faster than spedo says so must have some effect on computer.Hopefully someone comes up with programmer soon.lol.Mabye there is some other issue I hope it's just yours that causes this issue.Hate to say that lol.

 

[JACKAL]

For visual comparison OEM 27" tires on P1K and 26" Roctane XD on P500 to right, the P500 tires are same or a hair taller.

 

[Fullthrottle]

Could top speed in low 6th gear and high 6th gear be limited. You reach that top speed with big tires before you reach redline and spedo doesn't show you goin that fast and things get wonky.

 

[JACKAL]

Could top speed in low 6th gear and high 6th gear be limited. You reach that top speed with big tires before you reach redline and things get wonky.

No I don't think so, The measured difference from OEM tire to the 30" Roctanes is 16.5% larger, so at the speedo reading of 51 mph the corrected speed would be 59.4 mph. Maybe that's all it will pull those heavy tires and I could understand if it felt maxed out but the engine will surge just like you put you hand over the intake and cut off the air or in this case I suspect the computer cuts off the fuel.

 

[JACKAL]

In any case ran it nearly 100 miles in the Smokey Mountain trail of Royal Blue with the OEM tires and everything performed flawless. I still cannot get over how well it rides and absorbs the bumps and higher trail speeds, I would dare call it plush compared to the Pioneers that came before it. I am 100% happy with the machine just have to figure out the right combo on tires that doesn't kill the top end speed. I don't really need bigger tires but I definitely want tougher tires than the Bighorns even though they performed just fine from 8" snow & slush to mud well over a foot deep cut out by la logging operations.