If you are travelling 80mph in a 1600 how many rpm will u be doing?

I have twin kads and the engine is a 1600 but my gear box is from a 1300.

Just wondering how many rpm its doing in 4th @ 80mph?

Can i blow the gearbox?

my 1600 with unknown swinger box. either 1300 or 1500.

with 31 inch tyres on does 80mph at about 3000 revs

From memory, all being standard on a 1200/1300 box with a 4.375: 1 diff, the result is somewhere around 18.8 MPH/1000 RPM. Therefore, the revs would be around 4,300.

so whats redline on a 1600?

In other words at 80mph will anything break if i do cos the car feels like it go some more?

1300 box running a 15/65/195 profile with a 1835 used to sit at 85 mph all day long which was 4000 rpm so 80 would be just over the 3500 mark


steff..........

so in other words its fine to do 80mph in a 1600 with twin Kads?

Am i pushing the envelope?

pushing it a bit, all depends on the heat of the day how strong the donk is etc etc etc.. i ued to run mine at 85/90mph daily but it was a strong engine and it was in the uk so heat was not as bad.

I had a standard 1600 with twin kads in the back of my kombi and it used to run fine at 80ish for a couple of years till i drove for 6 hours only stoping to fuel once and it threw a rod.. was it the speed? was it getting tired and worn? honestly i would say the speed for that amount of time and the heat generated was the main casue but i never opened it all up to see(i blew it up 3 days before it was being sold and i moved to australia)

steff...................

cheers dont see my self doing 80mph for 6 hours just asking as sometimes I need to overtake dangerous vehicles and need the speed to do it safely have done it before but have been scared i was going to blow something

my 1600 ran at 80mph at around 42-4500 revs, its close to redline, but the beetle took it well

get a rev counter... then you know for sure... 👍

i had one that ran at 5800 rpm at 80mph with 15's. yes in fourth

it was geared a little low🤪

If you need to go fast for a 15 or 20 seconds to overtake something, that's fine - within reason. Many of us pull 6500rpm plus when racing etc with appropriate cransk etc etc. But you can't do that all day - 4000rpm is the maximum constant cruising speed in a standard Beetle and it is less for a Kombi. Any more than that and the engine really can't shed its excess heat fast enough. And teh crank can begin to wobble as it isn't designed to spin that fast!!

How old/tired is your engine?

Yes, get a rev counter - or at least borrow one to determine YOUR revs at say, 100km/h and then calculate form there. My Beetle (1916cc 4.1 diff and 205/60/15 tyre - ie: almost standard gearing) does about 3200rpm at 100km/h, so 3500rpm is around the freeway speed limit.
It can pull a constant 5500rpm in top gear - 175kmh, maybe more, I haven't tried any faster yet! - for overtaking (!) etc but only for a minute or two as the oil temp soon rises, even with Hoodjax.
Hope this helps



[ Edited on 10-2-2006 by VWCOOL ]

Domone, that calculates to 13.8 mph/1000 rpm. Were you running on the rims without rubber?
Both speedos and tacos can be inaccurate or maybe stuck in 3rd gear!
Get that taco checked and let's not forget that a "blue line" is as costly as a "red line"! Our beloved VWs would cruise flat out all day long at "maximum and cruising speed" AS LONG AS IT ISN'T IN HOT OLD OZ! Otherwise we are continually rebuilding engines as well as keeping the boys in blue with good pay.

The above post looks a good indicator for you although it uses the later diffs from the Type 3s and later Beetle with 4.125:1 ratio. This gave around 19.8 mph/1000 rpm.







[ Edited on 10/2/2006 by 1500S ]

When I had my first beetle (a '72 1300 twinport) it was 2 years old and completely standard it would sit on 70mph and do 3500 rpm.

1500S wrote:Domone, that calculates to 13.8 mph/1000 rpm. Were you running on the rims without rubber?
Both speedos and tacos can be inaccurate or maybe stuck in 3rd gear!
Get that taco checked and let's not forget that a "blue line" is as costly as a "red line"! Our beloved VWs would cruise flat out all day long at "maximum and cruising speed" AS LONG AS IT ISN'T IN HOT OLD OZ! Otherwise we are continually rebuilding engines as well as keeping the boys in blue with good pay.

The above post looks a good indicator for you although it uses the later diffs from the Type 3s and later Beetle with 4.125:1 ratio. This gave around 19.8 mph/1000 rpm.

i wasn't joking. 800 rpm drop between each gear.was like a motor bike brrnmmmmm bah brmmmm bah brmmm bah brrm ...37mph (6okm/h). putted around at 50mph (80km/h) @4100 for 12 months or so, wheel spin in forth was always interesting

any ways, having come to my senses, i now do 3300rpm at 65mph with an early swinger box (6 volt) with 15s,

i will have a look at 80mph this arvo, but agree with the above- thats too fast for the engine to live a fruitfull life.



[ Edited on 11-2-06 by dumone ]

ok now so now im confused:

so a 1600 with twin kads @ 80mph in a 1300 gear box is redline is this correct?

Im running a 1600SP with a 1200 gearbox 4.275 diff. It'll do 80mph pretty easily. heatwise its not too bad, but I wouldnt do it on a 30deg+ day for hours on end. It's about maximum load for the stock engine.

"6okm. putted around at 80kmph @4100 for 12 months or so, wheel spin in forth was always interesting"

Now hang on! Now I'm realy confused with your technical info much more!!!!!

kmph...... Does that mean kilo miles per hour?? We have followed along with mph which IS miles per houre which I have stated in my quotes from tech info. Are you talking in kilometres per hour or trying to teach us oldies "new maths". Let's use the correct abbreviaton of kph for our metric version!

The above post post doesn't mention revs but yes it is all true and the revs are 80 divided by 18.8 and you'll have close about 4,200 revs with standard tyres.

1500S wrote:"6okm. putted around at 80kmph @4100 for 12 months or so, wheel spin in forth was always interesting"

Now hang on! Now I'm realy confused with your technical info much more!!!!!

kmph...... Does that mean kilo miles per hour?? We have followed along with mph which IS miles per houre which I have stated in my quotes from tech info. Are you talking in kilometres per hour or trying to teach us oldies "new maths". Let's use the correct abbreviaton of kph for our metric version!

The above post post doesn't mention revs but yes it is all true and the revs are 80 divided by 18.8 and you'll have close about 4,200 revs with standard tyres.

domone?

i take it you're hacking on me, dumone?

tacos........

they taste good but give no indication of your engines revolutions per minute!

houre......

how many minutes in an houre?


Now I'm realy confused with your technical info much more!!!!!...........

i'm REALLY finding that sentence confusing, but i know what you are getting at.................

wakey wakey,its not that complicated, it's called a typo! first post was mph, second i spoke of kph, but sadly added a "m" in there and confused the s$@t out of you hey? if you really check up, you would see i mis-spelt fourth as well! i have edited the post to help you out. you must be ancient if your saying i'm teaching the oldies. if you really want to be technical about it, we should be using the forward slash-------m/h ---- km/h...




.....anyways did the flyby this arvo, with my now standard 1300cc/ early swing axle/ 6 volt gearbox.

4100RPM AT 80MPH. tooo many rpm to cruise at for sure considering the redline of a stock bottom end is normally around 4500rpm.

i have always cruised at a max of 3600rpm, more than that seems to increase the heat too much- even 3800 makes the world of difference.

sit on 70 MPH, and be safe.

[ Edited on 12-2-06 by dumone ]

XXX-1.8T wrote:cheers dont see my self doing 80mph for 6 hours just asking as sometimes I need to overtake dangerous vehicles and need the speed to do it safely have done it before but have been scared i was going to blow something

yes its fine for short burst's

XXX-1.8T wrote:ok now so now im confused:

so a 1600 with twin kads @ 80mph in a 1300 gear box is redline is this correct?

almost, 85MPH will redline it.

Hi Dumone. Thought there may have been a typo there but sometimes we read something over and over and can't see what's wrong and why someone is having a go!, (hopefully only "tounge, woops! tongue in cheek!)! Ancient? Well I guess some of us seem to be getting into that category! Hopefully our ramblings from the stone age will still be of some help to those who have only discovered VWs in the last 20 years as there is still plenty of the unknown hidden in the previous years.

After driving the larger modern cars with the high gearing for the last 20 years, the run to and from Nambucca in 2004 had me concerned at the revs of the Notch at 110 (plus a bit!) k/ph was doing. Quite a bit of difference to the 1,900 rpm I've become used to!

See you at 'Bucca? Any Taco shops there?



[ Edited on 12/2/2006 by 1500S ]

one tacho shop,

no taco shops

if the racing is on at raleigh, i will put my close ratio box in my car and you can come for a ride and calculate the technical details for homework.

i remeber checking out your notch last show, sussing the join at the rear pillar of the two tone colours

i was at the first spectacular, were you there?

see ya there, i will shout you a beer.

🙂

chances are if you are running a 1300 cc swing axle gearbox then the the ring and pinion is 4.375 which means in 4th the final ratio is 3.89:1, multiply this by the rolling circumfrence of the tyre and calculate the rpm. this combo with standard size 165/15 you would be doing 3520rpm at 110 kilometres per hour. aint too many places where you can cruise faster than this.

Dumone

After teaching apprentices all these years I'm over homework................... but I'll take you up on that pint! We'll have a longer talk if you come to the Nats. Didn't do the join as per the original S as I thought at the time it didn't look as good as the horizontal cutoff. Maybe a repaint when I retire!

You've jogged the grey matter on being ancient so I might put a post on "chit chat" on the VWs of "Wandin Valley" all those years ago!

Regards from the Hawkesbury



[ Edited on 12/2/2006 by 1500S ]

mate, there was no malace in it, just pointing out i ain't that fresh myself.

funny thing is, i said to the missus "check this out, this guy has to be a teacher"--i had a good laugh when i checked out your profile.

Yep! Got the occupation right but after all these years with the changes in the way trades are going I'm ready to stay at home and play in the shed! In those years from 1980 to 1987 there were up to 13 teachers in the Fitting and Machining section at Meadowbank....... now there are two of us! I have seen Auto, Auto Electrical and Panelbeating close. The government doesn't want "hobbyist" people cluttering up the classes. I'm sure many of the guys on this forum have gained skills from the old Journeymans Panelbeating courses at various colleges. In the past we ran Fitting and Machining Workshop Practice classes for the same reasons. These types of course are now TAFE PLUS courses at a VERY high fee structure which turn the average person away. From Penrith to North Sydney there are only a handful of colleges left with my trade so it makes it difficult for apprentices who do have a job to get into a nearby TAFE. This year we are completely full and having difficulty getting part time teachers to help. Of the ones who did apply, well, you wouldn't feed them!

Now! The biggest problem I have is "do I put disks and a 1916 in the Notch or keep it standard"!!!!!!!!

See you at the Nats?

Regards, "the not really grumpy old TAFE teacher" !!

ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

1500S wrote:In those years from 1980 to 1987 there were up to 13 teachers in the Fitting and Machining section at Meadowbank....... now there are two of us!

hey......... i did my apprenticeshipat Meadowbank! 1979 - 81. A Hoover boy
You would have had to put up with a few of us!

😢All gone now though :cry

XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

Costa....I'm up and down the F3 everyday in my bug. I run 135/165s. I sit on 65-70mph, with an occasional "blast" to 75-80mph if I need to overtake in a hurry. This is a standard, fuel injected motor ie, no Kads. I've run those speeds many years up and down the expressway, and this motor has held together, very, very well (touch wood). In the past though I have dropped a valve and lost compression (in other cars), so......hold off on the excessive speed, watch the nutters in the fast lane, and keep the longevity in your motor by dropping the speed back 10mph.

I agree with squizzy. keep the speed down. VW engines don't like to rev too high for hours on end.

When I drove my buggy from Canberra to Perth via Highway 1, I put a PERTH OR BUST sign on the back, ticked over at 95/100 km/h, got lots of toots and waves and once, with a tail wind I got 45 mpg out of it. The engine sang along as sweet as you like the whole way.

At 120km/h she was noisy, rattly, thrummy, and getting unstable.

Don't try to keep up with modern traffic if you want your engine to last.

think about it if your cars 30 years old things are a bit sad and if you drive any old car hard it will brake sooner then later,:cry
having said that i had a standard 69 1500 beetle and it was just in the zone at 70 mph just buzzing along.

[ Edited on 14-2-2006 by ian.mezz ]

I just built up a 1600 tp test motor to see what would happen if I machine of the piston skirts and lighten every thing off. My 61 bug with 1500 box and 195/65/15 will now reach 90 mph not a problem. I have been cruising in to work 40 km at 75-80 mph all summer. The only problem I have had is the motor was getting so hot I was getting fuel vaporisation on the 40C plus day so I put an elec. fuel pump on it. Am looking forward to pulling it down and seeing how it’s holding up. My tacko dose not read correctly so I have know idea what revs I’m pulling. Think I’m getting signal interference through the wire from the coil, and one had this problem?

XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

highly unlikely to blow gearbox

the engine will let go first.

you are approaching the redline at that speed (assuming a stock bottom end)

that is not a recomended cruising speed, however o.k for passing (short bursts)



[ Edited on 14-2-06 by dumone ]

XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

With this tyre combination, your speedo will be quite optimistic unless it has been recalibrrated, i.e. an indicated 80 mph would be somewhat less in reality. How are you judging your speed?

hth

Im judging the speed from my speedo.

And my engine is a rebuilt balanced 1600 2.5 years old with an engel cam and now with twin kads and stock exhaust.

So can it still let go @ 80mph on short bursts?

if there is something wrong, they will let go at any r.p.m

modulus wrote:

XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

With this tyre combination, your speedo will be quite optimistic unless it has been recalibrrated, i.e. an indicated 80 mph would be somewhat less in reality. How are you judging your speed?

hth

speed variations will depend on profile of the tyres, and the width

like wise with rpm and rear tyre profile

[ Edited on 14-2-06 by dumone ]

[ Edited on 14-2-06 by dumone ]

XXX-1.8T wrote:Im judging the speed from my speedo.

And my engine is a rebuilt balanced 1600 2.5 years old with an engel cam and now with twin kads and stock exhaust.

So can it still let go @ 80mph on short bursts?

now we are getting some info!

is the crank counter weighted

XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

Hi Costa are they 135/80/15?

all i know the engine has been balanced.

the tyres are Michelin 135 ZX's not sure of the profile but they are lower profile than my 165's

why the hell should front tires matter. they throw the speedo out a little. but not too much in my car (according to the gps) the rear profile is the only one that affects the revs/mileage etc etc

dumone wrote:

modulus wrote:

XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

With this tyre combination, your speedo will be quite optimistic unless it has been recalibrrated, i.e. an indicated 80 mph would be somewhat less in reality. How are you judging your speed?

hth

speed variations will depend on profile of the tyres, not the width

like wise with rpm and rear tyre profile

[ Edited on 14-2-06 by dumone ]

The height of a radial tyre is determined by the width X the profile; 'speed variations' will therefore depend on the width and the profile. Between a 135 and a 155 front tyre there is about 5% difference in diameter, directly affecting the speedo accuracy, assuming that 155's are equivalent to standard issue. Couple with a relatively large (comparatively) width (and therefor diameter) rear tyre, the actual engine RPM at an indicated 80 mph might be quite low compared with the rpm of s standard tyred bug. Which, after all, is directly relevant to the amount of engine stress at and indicated 80 mph.

If, as XXX-1.8T has indicated above, the front tyres are lower profile than the rears, then the above differences and their effects are magnified.

hth

[ Edited on 14-2-06 by modulus ]

modulus wrote:

dumone wrote:

modulus wrote:

XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.

Im running 165's rear and 135's at the front!

With this tyre combination, your speedo will be quite optimistic unless it has been recalibrrated, i.e. an indicated 80 mph would be somewhat less in reality. How are you judging your speed?

hth

speed variations will depend on profile of the tyres, not the width

like wise with rpm and rear tyre profile

[ Edited on 14-2-06 by dumone ]

The height of a radial tyre is determined by the width X the profile; 'speed variations' will therefore depend on the width and the profile. Between a 135 and a 155 front tyre there is about 5% difference in diameter, directly affecting the speedo accuracy, assuming that 155's are equivalent to standard issue. Couple with a relatively large (comparatively) width (and therefor diameter) rear tyre, the actual engine RPM at an indicated 80 mph might be quite low compared with the rpm of s standard tyred bug. Which, after all, is directly relevant to the amount of engine stress at and indicated 80 mph.

If, as XXX-1.8T has indicated above, the front tyres are lower profile than the rears, then the above differences and their effects are magnified.

hth

[ Edited on 14-2-06 by modulus ]

i know, i should of had "and" in there instead of "not" hey, sorry

we should have asked for more info right from the start too

tyre size and profile front and rear...

which 1300 box-the late or early

engine mods-specifically bottom end, cooling aids/mods?................

we are learnning more tho as we get along.

:kiss

[ Edited on 14-2-06 by dumone ]

nah no other mods thats about it.

The 1300 gearbox not sure if its early or late car was made on the 16 July 1965 and was rego'd in Australia in 1966.

Heres a pic of my baby:



:beer

nice ride, classic to imagine that rounding up the non-believers at 80mph:thumb

Bit hard to say,but,if your tyres are ZX 135 SR 15 then they have a circumferance of 1821mm and diameter of 600mm and width of 137mm,therefore i think your speedo which runs off the front tyres will read 9-10% too high.So if correct your now doing 72mph and about 4000rpm,but hey these are my guesses with limited research so its possible im wrong,and on the bright side at least my post count is goin up :thumb

so now we are getting to the bottom of things👍

so u reckon 72mph in 4th would be 4000rpm

what the redline on a 1600?

4400rpm :thumb

cheers!