audi 016 & 302 windsor problems

[joe]

hi all,

i need help with the 302 windsor & audi 016 setup that i'm running in my cav gt40. the 302's standard, & the 5 speed audi box has the 3.89 final drive - my second one - same problem. my car revs too high & runs out of breath / gears. i only get 140 kph in 5th gear running at 6000rpm. some say it's ratios, some say i need to make a gear cluster change to the gearbox, & i'm even wondering if the problem's not with the motor. i haven't got a clue as to what's wrong or where to go. on paper i'm surposed to get about 250 kph, & i'm not close. have you ever come across a similar proble, & do you have any advice or solutions on where to go from here? finally, the clutch doesn't slip.
much appreciated.
regards.
joe.
you can reply to [email protected] or [email protected] (at home)

 

[Neal]

The 016 ratios are less than optimal for these applications. German Transaxle in Bend, Oregon, USA did did a customer ring and pinion for the 016 which is well documented here.
http://www.gt40s.com/forum/gt40-tec...stom-3-17-r-p.html?highlight=german+transaxle

As I recall there was another outfit in Australia or New Zealand that was offering a custom cut set as well. There are quite a few posts on this.

Home - German Transaxle of America

 

[Chuck]

Joe:

We have essentially the same set up. Same 016 and same final drive of 3.89. Fifth gear .86. Your 140 KPH would be about 90 MPH.

Have not payed close attention to our revs, since our focus has been on Weber tuning thus far. But have noticed that at 65 MPH (100 KPH) it is turning at over 3000 RPMs. That may be good for a four banger, but not a V8. Sure do wish it had a taller 5th gear ratio.

Some time ago Hershal sent me the following message:

Another real good modification would be to buy a ring and pinion from my friend Mick in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com

<st1lace w:st="on">Australia</st1lace></st1:country-region>. He makes it 322:1 which really improves the final drive in 5th gear. You will be turning 2150 RPM's at 75MPH instead of 3400 RPMs at 75 MPH. Here is his link.
http://www.mentalperformance.com.au/
The price is around $2200 but it's worth it. Give them a call or send Mick an e mail. He will be glad to answer your questions.


I never followed up on this but it may be worth exploring. Sounds like a big job to install it and the price is more than I paid for the tranny.

Let us know if you get the issue resolved.

 

[Chuck]

Neal:

Just saw your post and the link to MitchD's thread. Noted it is four years old. Just sent a PM to see if that is still an option. Would be curious to know if anyone has had any experiance with that modificaiton, because it looks like a good option.

Chuck

 

[joe]

thanks for the replies boys, but i don't think that re-engineering is the answer, will just be too costly. we can get used 016 boxes here for around 200 dollars & 01e boxes for around 600 - 1000 dollars, round about. i am no expert on 302's & audi gearboxes & would like to post the following couple of questions if i may.
1. i know of quite a few other standard 302 windsor & audi 016 setups where there are no problems as all, why then this gear ratio problem on a handfull?
2. from all your experience, which is the best audi box to use on a 302, to handle the high revs? is there the one box i can go & buy that'll do the job?

 

[Terry Oxandale]

So if a 3.89 R&P ratio uses a .86 5th gear ratio, then the overall drive ratio should be around 3.345. Then at 6000 RPM, your tires should be rotating 1794 RPMs, which for a 26" tall tire (you appear to be runnning a taller tire for the 155 MPH top speed at 6000 RPM) is 146514 inches per minute, or 138 MPH.

Something does not add up right here. I had a 4.11 rear end 240Z that I raced (short courses) with an .80 fifth gear ratio that did roughly 70 MPH at 3000 RPM (similar situation here), which indicates to me your speedo is off, is using the wrong speedo gear, you forgot to shift gears (sorry, had to add that), or something obvious is being missed here, especially with others running this combination as only an inconvenience.



ox

 

[Chuck]

Joe:

Following is data on gear ratios. You can compare your tranny and see if you have the most advantageous ratios. The underlined text is the tranny I am using.

It does seem that you should be getting a lot more than 90 MPH / 140 KMH @ 6000 RPM in 5th gear despite the Audi 016 gearing.


Audi transaxle Data
Audi 100/200/9000 five speed manual transaxle gear and differential ratios
Type Ist 2nd 3rd 4th 5th Rev Diff Speedo drive
013 Serial Number prefix 3T 3.46 1.79 1.07 0.78 0.60 3.17 4.11 0.52
013 Serial Number prefix HE 3.46 1.79 1.13 0.83 0.68 3.17 4.11 0.52
013 Serial Number prefix HF 3.46 1.79 1.13 0.83 0.68 3.17 4.11 0.52
093 Serial Number prefix 3Q 2.84 1.52 0.90 0.64 0.48 3.16 5.22 0.52
016 Serial Number prefix AAZ 3.60 2.13 1.46 1.07 0.86 3.50 3.89 0.52
016 Serial Number prefix 3V 3.60 2.13 1.46 1.07 0.83 3.50 3.89 0.52
016 Serial Number prefix 3K 3.60 2.13 1.36 0.97 0.78 3.50 3.89 0.52
016 Serial Number prefix 5N 3.60 2.13 1.36 0.97 0.73 3.50 4.11 0.52
016 Serial Number prefix 3U 3.60 1.88 1.19 0.84 0.64 3.50 3.89 0.52
016 Serial Number prefix BMO 3.60 1.94 1.23 0.903 0.684 3.50 3.89 0.52

Audi 100/200/9000 four speed manual transaxle gear and differential ratios
Type Ist 2nd 3rd 4th Rev Diff Speedo drive
014 Serial Number prefix QN 3.46 1.79 1.07 0.70 3.17 4.11 0.52
014 Serial Number prefix 4X 3.46 1.79 1.07 0.70 3.17 4.11 0.52

The 016 boxes have the selector shaft on the left hand side, all other boxes have the shaft in line out of the back of the box.

 

[Dave P]

I called the link at the top of this thread. They are out of 3.22 ring and pinions. The need 10 orders to run a batch.

 

[Steve26]

I have the Audi 016 5N box with 4.11 gearing on a 302 and I have been 135 MPH in fourth at 6000 RPM, I have not had a safe place to see what it will do in fifth but rest assured it's way over 150 MPH. I think there is something wrong, are you sure your final is 3.89?

Steve

 

[Cliff Beer]

Joe,

Something is definitely off. Attached is a gear ratio calculator for the 016. At 6,000 rpm you should be seeing 120mph+ even with the least favorable 016 ratios. Couple questions:

1. What wheels are you running and what dimension? Typically it's around 26-26.5 for a rear GT40 wheel,
2. What code do you see stamped on your 016?
3. Have you confirmed that both your tach and speedo are reading correctly? Had to ask.

If you can find lots of 016s in your neck of the world then it might be best to go find a box with better ratios and see what improvement can be had.

 

[joe]

I must say that I am in agreement that somethings off. Speedo not connected, measured it to the t with a gps. My rear tyres are 15 inch with bf goodridge high wallsn total overall around 600mm dia. A friend also made some calcs and acc to that I must reach 256kph on 6000 rpm. Can this not all be an engine thing? What difference can a cam make to rpm? I have a cam in the motor somewhere in the 290's, not exactly sure. Maybe I must have the engine power delivery etc checked, but can that be done with the problem in discussion? Just wondering. You can all see that I am out of my depth here, and very frustrated! Thanks a mil for all the input, I do appreciate it.

 

[Ian Anderson]

Joe

Is your RPM gauge reading correctly

A lot of these tacho's are set for 4 / 6 / 8 cyl applications and if you have yours on the 6 instead of 8 it will read 6000 rpm when you are actually doing 4500 rpm

Worse still if you are set to 4 cyl you will only be doing 3000 rpm when your gauge says 6000

Worth hooking up to a garage diagnostoc machine aas a quick way to rule this out

Cheers
Ian

 

[Neal]

Chuck,

I have a GTA box in my car with a Quaife LSD. It is night and day ahead of my original 5N box. It's the perfect ration for my combination. I can cruise in 4th at highway speeds. The ratios are like a production car. It's easily the best modification I've made. We'll worth the money.

 

[joe]

well weekend's here & i'll continue the thinking on monday. i called a mech who suggested we put the car onto a dyno and do a diagnostic to check the power delivery of the motoer, the rpm, the bhp on the wheels, the ratios, etc, etc.

i've up to now been searching the earth for the solution - but probably need to find out exactly what the problem is before finding the remedy.

i have still not had a single reply from anyone saying -.".....oh, i've had exactly the same proble.........."! this probably means that i do indeed have a bigger problem, we'll see.

cheers all.

 

[Bram Boekestein]

600mm dia is only 23.6 inches! (Are you running slicks?)
That makes a very big difference...but still 140kph is low

With a 3.89 final drive and 0.86 fifth gear and 600mm dia wheels you should be doing 126mph (202kph) @ 6000rpm according to the gear ratio chart.

Do you have a 0.86 fifth gear? This wasn't mentioned by you but by Chuck.

 

[Ian K]

Joe,

I highly doubt it is your engine. RPMs are RPMs, regardless of HP, torque, etc.
If the tach says you are spinning at 6000 RPM, but the GPS only shows 140 kph,
then the problem lies with

1) the tach
2) the GPS calculation
3) the transaxle ratios
4) significant power loss between the engine and transaxle

If it was an engine power issue, your engine wouldn't get to 6000 RPM. It wouldn't
have enough power to spin that fast. If your clutch is slipping madly/not engaging
properly, then it would be possible that the engine is spinning to 6000 RPM with
decreased resistance, and the transaxle shaft is not spinning at the same rate
due to clutch slippage.

Ian

 

[joe]

thanks ian, finally, some direction / answers!

i have to say this, and i am extremely grateful for everyone's input - but i often find that discussions in these forums actually just remain that............discussions! one could honestly spend a lifetime discussing this issue without making one metre's progress.

this is exactly what i've been hoping for, a directional checklist thru' which i can work, & i will now take it from here - process of elimination! please keep the feedback coming, but remember you're dealing with an architect - & a very non-mechanical one at that!

ps: there's alot of reference to a possible slip on the clutch - i had an old datsun when i was studying & i thought i know what a slipping clutch sounds like, or can this happen in such a way that you can't pick it up with the ear?

keep it coming, i can't wait to get it fixed & break thru'the 140kph BARRIER!!!

regards.

 

[joe]

joe again,

just a correction on earlier info, the overall rear wheel diameter is not 600mm but 680mm (295mm wide rear tyres), for what it's worth. i think i did mention that we've doen these cals, & on paper i should be getting around 256 kph. not on tar!

on gear ratio charts, we also have most of them here, but most of the gearboxes with those numbers aren't found in south africa. i know how to open a box to calculate final drive, but how do i calculate the ratio of the fifth gear (or any of the other)?

last bit of additional info - i have a 650 weber carb at present, not sure what different carbs would bring to the table, or if they'd have any effect on the revs?

cheers.

 

[Ron Earp]

My estimation is the same as Ian's #1, is that you're not turning 6000 RPM.

What sort of ignition do you have? Is the ignition adjusted for 8 cylinder operation? Is the tach on the same setup and properly setup?

 

[Ian K]

joe again,

just a correction on earlier info, the overall rear wheel diameter is not 600mm but 680mm (295mm wide rear tyres), for what it's worth. i think i did mention that we've doen these cals, & on paper i should be getting around 256 kph. not on tar!

on gear ratio charts, we also have most of them here, but most of the gearboxes with those numbers aren't found in south africa. i know how to open a box to calculate final drive, but how do i calculate the ratio of the fifth gear (or any of the other)?

last bit of additional info - i have a 650 weber carb at present, not sure what different carbs would bring to the table, or if they'd have any effect on the revs?

cheers.

Different carbs might affect the revs, but again, that isn't the problem. If
the engine revs, power isn't a problem, so carbs won't matter. If the
car had power issues, it wouldn't be able to rev high in the taller gears,
the resistance of the gears coupled with the weight of the car and the
friction of the tires would bog the engine down. Since you are turning 6000
RPM in 5th gear (assuming it is really turning 6000 RPM), the engine power
is fine.

You said that the engine revs too high - is that by tach reading or by ear?
If by tach check that first. Hook another tach up or use a timing light to
check that the tach is accurate.

My 240Z had a similar problem - the motor (a 280 block) revved just fine,
but once first was engaged, the car crawled. My tranny wasn't hooking
up properly, so I had to drop it and put it all back together.

Ian