[dougies_tx5turbo]

first off ive got a 2005 model jimny vvt manual with 82,000km.

so im looking at putting 215's on my car and i know thats a 7% reduction so to get back to stock i need to do this:
Mark III with Mark II gearbox + a standard Mark II Jimny Transfer + Stock diffs = 6% reduction.

My question is what will this be in percentage?
Mark III with Mark II gearbox + a standard Mark III Jimny Transfer + Stock diffs =?% reduction.
I dont understand this percentage stuff thats why i ask.

so im looking at getting all the parts ready to do my gear box swap in the future as ive just bought a series 2 gear box for cheap. so i would like to have the parts waiting for when i do my motor conversion. so basically i will be putting a series 2 gear box in with an m15 or m16.

What jack shaft will i need to replace the old jack shaft?
Will i need to modify much when replacing with an older model manual t-case?
Is it just a straight bolt up?

I know the gear box wont be.



Old questions that have been answered. new questions are above.
what is the biggest legal tyre you can put on a jimny? 215 75 15 are just over the legal limit, so really 215 70 15 or 205 75 are the highest you can "legally" allowed to go

when i was into sports cars i thought you could legaly go up 2 sizes as long as its only 20mm bigger in rolling diametre, so i would think it would be the same for all cars, is this true for 4x4's?yes in some circumstances in some cars

what is the best tyre size combo with stock gearing, 215 75 15 or 205 70 16?215 75 15

does the vvt have the same extractors as the 2004 m series motor? yet to be answered but more likely yes

im looking at running 215 tyres and im wondering if i take a transfer case from a 2000 model g13bb and put it in my car would this help a tiny bit with gearing? or do all manual jimny's have the same gearing ratio?no this will not be a good option

will the older model rear tail shafts be a straight swap? the series 2 tail shaft will bolt on, to replace the cv

[smiffkid]

Not to sure If there is a difference between the cases. But the change in tire size won't make a lot of difference. Hardly enough to suffice a tease swap imo

[dougies_tx5turbo]

i know its not really worth the swap for the size of tyre but i can get a cheap transfer and i dont like push buttons because i keep knocking them. i dont like the power now with 205's and putting the extra weight of 215 mud terrains would make it more sluggish.
Doug.

[smiffkid]

M15 swap more power more economy less revs on high way. Other wise I know auto tcase is 20 percent in high. But to much reduction.
Can always try It n see. Not hard to swap a case

[dougies_tx5turbo]

yeah but the auto tcase would be costy, ive seen someone do it on here. the m15 swap is on the cards in about 10 months time when the missus is off her p's, as we both use the car for our baby.

[smiffkid]

Ah yup. With the motor increase u will bearly notice the slightly bigger tires. Do u know weather yr diff ratios r 4.3 or. 4.1

[dougies_tx5turbo]

dont know the ratios. i saw a thread about 6 months ago showing all the gear ratios between mark 1 to mark 3 in the different models and i ve been trying to find it but i cant. maybe i saw it on another forum.

[smiffkid]

Is yrs mark 3

[dougies_tx5turbo]

i think so its the first of the vvt

[smiffkid]

So they be 4.3s. The gearing thread was on this forum. Prob few pages back now tho

[dougies_tx5turbo]

found it hope it help me abit http://auszookers.com/forum/viewtopic.p ... 83&start=0

[BertZook]

dougies_tx5turbo wrote:

dont like the power now with 205's and putting the extra weight of 215 mud terrains would make it more sluggish.
Doug.

thats how jimnys are... get used to it

like smiffkid said, for 215's is not worth the gearing at all..... if u happen to get more reduction, great ull have a bit extra power to take offs, but ull be sacrifice in revs at highway speeds... vvts jimnys go good at 3200rpms... u might get the reduction great for bit extra power but now goin into 4200rpms at highways, witch its annoying

[zukenutter]

As the other guys have said with 215s you shouldn't bother with the gearing. 215s on a VVT (Mark III) would go well.
A stick shift transfer from an earlier Mark I (G series motor) or Mark II (Non VVT M Series) would give you about 25% reduction with is way too much for the 7% bigger 215s.
If you were to swap to the earlier transfer you'd also need a custom jack shaft or a flange spacer. Series II lengthened a few cm.

[dougies_tx5turbo]

thank you for the information, this is what i wanteed to hear before i went ahead and bought it. i think i will just spend the money on extractors.

[Mike57]

Before you spend money on extractors take a close look at these dyno curves. Overall both torque and power was desreased on this 2005 model.

http://www.jimny-crew.com/jimny-on-the-dyno.html

Be careful of the scales and note that one is in Nm and the other in ft Lb. When you do the conversions it's not looking like a worthwhile modification. Not sure if anyone else has before and after dyno results as a comparison?

The rules on tyre sizes I believe are state based. In Vic I think 215/75 is the biggest legal size but check with you own state department of transport or equivalent.

[zukenutter]

^^. The way that article reads to me is the results sheet is from test one.
Test one as he says is pre extractor, he planned three tests and unfortunately hasn't posted test two or test three.
He points out that the power is down from factory quoted output due to his Jimny having 100,000km on the clock. Power decreases with age.

Bottom line this is not a guide for extractor fitting decision IMO.

[Bugsta]

dougies_tx5turbo wrote:

first off ive got a 2005 model jimny vvt manual with 82,000km.

what is the biggest legal tyre you can put on a jimny?

when i was into sports cars i thought you could legaly go up 2 sizes as long as its only 20mm bigger in rolling diametre, so i would think it would be the same for all cars, is this true for 4x4's?

Quote from TMR Modifactions PDF... The rim diameter may be varied from the standard size but the overall diameter of the tyre must not vary by more than +15mm or -26mm.

Doesn't allow much. Even going from 205/70 to 205/75 is a 20mm increase.

Quote:

what is the best tyre size combo with stock gearing, 215 75 15 or 205 70 16?

Down to personal choice and what you want the vehicle to be capable of. My 235/75/15's are a little on the big side for the gearing but not nearly big enough to plough tracks made by Patrols on 35's

Quote:

does the vvt have the same extractors as the 2004 m series motor?

Not sure on this one. I think the block is effectively the same.

Quote:

im looking at running 215 tyres and im wondering if i take a transfer case from a 2000 model g13bb and put it in my car would this help a tiny bit with gearing? or do all manual jimny's have the same gearing ratio?

According to data I have gathered, Mark I&II transfer cases are all 1.32:1 and 2.145:1, which makes High range 30% lower and Low range 7% lower. 7% is at least an improvement but your Jimny will be reving very high on the highway, especialy with those 215's. My calculations suggest that with 32's or so, it would be useable. But your 7% gain in low would be lost. A MIII auto will give you 30% High and Low. Keep an eye out. They do crop up from time to time.

Quote:

will the older model rear tail shafts be a straight swap?

Should be. I have installed an MII in my MIII

dougies_tx5turbo wrote:

i know its not really worth the swap for the size of tyre but i can get a cheap transfer and i dont like push buttons because i keep knocking them. i dont like the power now with 205's and putting the extra weight of 215 mud terrains would make it more sluggish.
Doug.

The Jimny 4WD buttons require a 4 second press and hold so thats not an issue. I installed a high flow air filter and extractors. I think it helped a little.

smiffkid wrote:

M15 swap more power more economy less revs on high way. Other wise I know auto tcase is 20 percent in high. But to much reduction.
Can always try It n see. Not hard to swap a case

An engine change does not mean less revs, at any speed. It has no bearing on the final road speed or revs the engine is doing at that speed. The only effects an increase in power has, is more power (ie better acceleration), or less pressure on the pedal for the same result and possiby better economy for the same reason.

Sounds like you have the time, so you could look out for a m16a from a (06?) GV. Rare but they are around. Will cost you a lot more than a m15a though. I have heard of a few people recently doing an m18 upgrade successfully. Some on this forum.

[zukenutter]

Bugsta wrote:

dougies_tx5turbo wrote:

first off ive got a 2005 model jimny vvt manual with 82,000km.

what is the biggest legal tyre you can put on a jimny?

when i was into sports cars i thought you could legaly go up 2 sizes as long as its only 20mm bigger in rolling diametre, so i would think it would be the same for all cars, is this true for 4x4's?

Quote from TMR Modifactions PDF... The rim diameter may be varied from the standard size but the overall diameter of the tyre must not vary by more than +15mm or -26mm.

Doesn't allow much. Even going from 205/70 to 205/75 is a 20mm increase.

5% of 205 = 10.25mm increase

smiffkid wrote:

M15 swap more power more economy less revs on high way. Other wise I know auto tcase is 20 percent in high. But to much reduction.
Can always try It n see. Not hard to swap a case

An engine change does not mean less revs, at any speed. It has no bearing on the final road speed or revs the engine is doing at that speed. The only effects an increase in power has, is more power (ie better acceleration), or less pressure on the pedal for the same result and possiby better economy for the same reason.

Sounds like you have the time, so you could look out for a m16a from a (06?) GV. Rare but they are around. Will cost you a lot more than a m15a though. I have heard of a few people recently doing an m18 upgrade successfully. Some on this forum.

I initially read this comment like that too but I think smiffkid meant that swapping to more power would make the bigger tyres acceptable thus, in combination, reducing RPM

[smiffkid]

Yea that's Wat w ment sorry

Yr right zukenutter

[Bugsta]

zukenutter wrote:

Bugsta wrote:

dougies_tx5turbo wrote:

first off ive got a 2005 model jimny vvt manual with 82,000km.

what is the biggest legal tyre you can put on a jimny?

when i was into sports cars i thought you could legaly go up 2 sizes as long as its only 20mm bigger in rolling diametre, so i would think it would be the same for all cars, is this true for 4x4's?

Quote from TMR Modifactions PDF... The rim diameter may be varied from the standard size but the overall diameter of the tyre must not vary by more than +15mm or -26mm.

Doesn't allow much. Even going from 205/70 to 205/75 is a 20mm increase.

5% of 205 = 10.25mm increase

smiffkid wrote:

M15 swap more power more economy less revs on high way. Other wise I know auto tcase is 20 percent in high. But to much reduction.
Can always try It n see. Not hard to swap a case

An engine change does not mean less revs, at any speed. It has no bearing on the final road speed or revs the engine is doing at that speed. The only effects an increase in power has, is more power (ie better acceleration), or less pressure on the pedal for the same result and possiby better economy for the same reason.

Sounds like you have the time, so you could look out for a m16a from a (06?) GV. Rare but they are around. Will cost you a lot more than a m15a though. I have heard of a few people recently doing an m18 upgrade successfully. Some on this forum.

I initially read this comment like that too but I think smiffkid meant that swapping to more power would make the bigger tyres acceptable thus, in combination, reducing RPM

5% of 205 = 10.25mm increase x 2 = ~20mm

[zukenutter]

Haha yeah fair enough

[2stroker]

Just chiming in here, I have not had a lot to do with Jimny's but the one I have looked under have looked under had a CV instead of uni at the transfer end of the rear tail shaft and it was cactus which was why the car was at the workshop. I have seen people looking for rear tail shafts for Jimny's and seeing that Doug was asking about tail shafts and bugsta said he had changed his, is this a common problem/weak point and if so what are people doing to overcome it, i.e. are they modifying sierra ones to fit or what upgrades are they using.

[zooky08]

When you do the Ora Sierra case swap a Sierra front drive shaft ends up being the new Jimny rear shaft I'm pretty sure

[Mike57]

Zukenutter

The dyno curves for the before and after are on that web site (one set in January 2011 and another from June 2011). It shows a drop in both power and torque after fitting the extractors and upgrading the exhaust (after you convert torque from Nm to ftLb and replot on the same scale). The results that are not there are the ones where he said he was going to remove the extractors and go back to the stock manifold with the upgraded exhaust. I agree that one result is not something to go on alone but it does raie questions and so I was wondering if anyone else has before and after dyno results. I know everyone that has upgraded the exhaust says they feel an improvement but I am looking for the evidence.

Mike

[2stroker]

Zukenutter, mate if you go into that site he does a second dyno run and says this.......

After the extractors had been installed:
I felt the engine was breathless and laboured, fuel economy was a little worse, the exhaust note had not changed and worst of all,
the car still slowed up hills in 5th gear.

The Dyno confirmed the worst:
Down 6hp to 70.5hp, not a great result, but I had not finished yet.

After the whole exhaust was replaced:
The engine is free reving, fuel economy was back to the original consumption levels, it sounded great (not too loud as instructed), I felt any losses in hp were regained and then some more,
but it still would not climb hills without losing speed.

It is poorly written and leaves you guessing but reading between the lines it seems that he has done a second dyno run with just extractors and the standard exhaust and gone a little backwards, it insinuates that he then fitted an exhaust to match the extractors and has noticed improvement but has yet to throw it back on the dyno.

With my own experience I have found that playing with exhausts can not only add some power it can often move the point in the rev range at which the power is developed, this can make negligable difference or be to the benifit or detriment of the driveability depending on the rev range in which you do most of your driving. For instance in my crappy old hilux I fitted extractors and a 2" exhaust with free flowing muffler and was disapointed that all it did was make more noise and feel a little doughier off the mark, (I drive the car everyday to and from work through suburdia and just plod along lazy shifting it at low rpm), however the first trip that we did away with the extractors and new exhaust it was noticable how much nicer it cruised at 100kph and it returned better fuel figures on the trip. On the open road now I could probably keep up with an overloaded Diahatsu Terrios towing a boat.

[JrZook]

I must say there is somethign very bizarre with that second dyno graph. It doesn't taper off nicely, it hits a brick wall and levels at 70HP

[2stroker]

Mike I am no expert on dyno charts but I know from experience that the car that has the highest reading on a dyno may not perform as well on the road as a car that has a lower reading, it also depends on factors like how broad the power and torque range is, comparing the two charts it seems although the second chart shows lower overall figure the torque at least is more constant across the rev range.

I was speaking to a HQ racer recently about the combinations that they use to extract as much performance as possible and stay within the rules, I was surprised to hear that they choose to use the low compression 202 head rather than the high compression 202 head because although the high compression option made more power the low compression version develops better torque figures in the rev range where they need it for their races.

These charts are actually hard to compare when flicking back and forward because in one test the red line represents the 4x4 run and in the other the red line represents the 2x4 run, also one is in nm and one is in flbs, obviously not to hard to convert as actual figures but a bit more challenging if you want to compare the linial progression of a chart.

I see that in the 6 months between the tests the vehicle odometer has not changed (which may just be too lazy to type in the new figures) but does anyone know what does the "Correction SAE" and other readings on the chart refer to.

[Mike57]

2 stroker

The other problem is that the two graphs use different scales and this is why the cureves appear to have different shapes. When I plotted the curves by hand from the first graph on to the second graph the curves are exactly the same shape but there is a loss of torque and power after fitting the full exhaust with extractors. The other thing that does not seem right is the big increase in drive train losses between the first and second graphs which does not add to ones confidence level at all. The losses should be constant. You are right the 2WD and 4WD colurs are flipped over on the second one so that makes it even trickier to follow.

From a google search the SAE J607 is a stanbdard for power correction that takes into account the humidity, temperature and atmospheric pressure and converts the charts back to a standard reference level.

Overall I don't want to make decisions based just on these two dyno runs but I am still struggling to convince myself that the local exhaust shop can do more better than a team of prefessional automotive design engineers in Tokyo.

Mike

[Mike57]

Link to the article on corrected horsepower if you are interested. http://www.land-and-sea.com/dyno-tech-t ... epower.htm

[zukenutter]

I stand corrected. This is becoming a habit.