Thread: Turbo 202 into series 3. Possible?

Originally Posted by Lotz-A-Landies

Just need to clarify what drive-train you're running in that SIII.

The reasons:

• The maximum rolling circumference a 7.50 X 16 tyre is 2.47M (according to Tyre Size Calculator @ ExplorOz)
• 100KPH = (1000M X 100Km)/60 min = 1666.67 M/min
• wheel RPM for above = 1666.67/rolling circumference 2.47 = 674.763
• prop shaft RPM = 674.763 X diff ratio 4.7 = 3171.39
• mainshaft RPM = 3171.39 X transfer ratio 1.148 = 3640.76 RPM (equivalent of revving the ring off a Holden 6cyl engine)
• Overdrive possibility = 3640.76 X 0.77 = 2803.38 RPM

These are fixed mechanical ratios, there is no way you can get 2250 RPM @ 100KPH on a standard Series transfer even with an overdrive unless you are running larger radius tyres than 7.50 equivalent, have a high speed transfer box or modified diff ratios. (i.e. 3.54:1 diff ratios X Fairey overdrive = 2111.48 RPM @ 100 KPH)

See my signature.

Diana

Yes Diana, I see what you mean, thank you for the info.

I'm now quite puzzled as to my tacho reading.

When I purchased the vehicle I was assured it had all been rebuilt, with new high speed transfer box and all that. I just assumed standard diff ratio.

The speedo was working when I first got it and I have had a chance to verify it against a few overhead radar gantry's.

The speedo cable broke a few weeks later and I've been relying on the tacho since then. Yes, I do recognise that the gantry's aren't all calibrated the same, with 2-3 kph deviations between the posted readouts, but the gantry's readouts are nevertheless consistant. The same gantry always displays the same readout.

The tacho appears to be reading consistantly, though it's hard to know I suppose.

I have managed to acquire a replacement speedo cable, but unfortunately a slow seller took his sweet time sending it and it arrived 2 days after I'd left for the Xmas break, now thinking about all those cameras I went through, and looking at the data you provided is giving me a crinkly brow.

If the tacho is reading wrong, I sure hope it's consistantly reading wrong, meaning that I hope it sits on the same revs and doesn't fluctuate.

Thanks, you have me stressing now. Haha.

Originally Posted by navigation2000

Yes Diana, I see what you mean, thank you for the info.

I'm now quite puzzled as to my tacho reading.

When I purchased the vehicle I was assured it had all been rebuilt, with new high speed transfer box and all that. I just assumed standard diff ratio. ...

....Thanks, you have me stressing now. Haha.

You need to un-stress, the high speed transfer box answers one of the questions I asked. The remaining ones are overdrive or modified diff ratios. The usual ones would be 3.54:1 as the cheapest and most available or 4.11:1 Ashcroft C&P or similar.

A few of the regular tests will answer the Qs.

Diana

Originally Posted by rovercare

Thats a bit rude

Its either got 3.54 diffs already or an inaccurate tacho

Rovercare, I'm not wanting to go here, but. ....<snip> mildly confronting statement removed LAL <snip> ...

I asked a question to clarify a statement, which was not possible with standard running gear. I referred to my signature suggesting I would be interested in facts not fiction, which is soooo often what we get on these forums. 3.54 diffs was one of the answers I may have got, or the tacho answer, however I got a high speed transfer case which is part of the answer.

Originally Posted by Lotz-A-Landies

You need to un-stress, the high speed transfer box answers one of the questions I asked. The remaining ones are overdrive or modified diff ratios. The usual ones would be 3.54:1 as the cheapest and most available or 4.11:1 Ashcroft C&P or similar.

A few of the regular tests will answer the Qs.

Diana

Rovercare, I'm not wanting to go here, but. ....<snip> mildly confronting statement removed LAL <snip> ...

I asked a question to clarify a statement, which was not possible with standard running gear. I referred to my signature suggesting I would be interested in facts not fiction, which is soooo often what we get on these forums. 3.54 diffs was one of the answers I may have got, or the tacho answer, however I got a high speed transfer case which is part of the answer.

I have a bit of an update for you Diana.

On the weekend I went away again and while away I found the time to fit the NOS speedo cable.

I again took some readings with it as well as verified the tacho by using another known tacho, to see if they read different.

I don't know what's going on here, as both tacho's are saying the same thing, and my earlier statement that I was sitting on 2250@100kph was slightly wrong. I may have mentally opted to sit on 2250 as a safeguard, but the true reading appears to be 2450@100kph, as when I hit the radar display(3 times)at around 2500rpm, with speedo reading 100kph, the radar said 101kph. It's my belief that radar in particular is only 1 kph out, always has been.

Not sure on the math you gave, but I did cross check the tacho against a genuine GTS holden unit and they both read the same.

I'm not one to bandy around with facts, and until I know for sure what diff ratios are actually fitted to my diffs, I will still be none the wiser.

I'll sieve my old emails and endeavour to contact the previous owner to ask the question, for I reckon he will know the proper ratio details.

Further, my fuel economy has taken a decidedly positive leap in my favour since I fitted HEI ignition and Brisk Premium LGS spark plugs. I'm now getting at least 50 klm more per tank.

Thanks for the update Nav 2000, as you mentioned the other day you have a hi-speed transfer box which will bring you down from the ratio of the standard box.

I'm not sure of the ratio for the Hi-speed transfer (have asked on another thread) however it would probably not be sufficient to return the RPM you are reporting.

There must be some other factor, like 3.54:1 diffs.

e.g. if the Hi-speed conversion was 1:1 in the transfer box and you had 3.54:1 diffs, then in top gear of the standard box you would return 2389 RPM @ 100KPM (depending on your tyre size).

Keep us informed what you find out and I remain interested in your fuel ecconomy modifications.

Diana

BTW: Do you know on 202 engines, if there were differences between the stromberg carbies used with auto transmissions and with manual transmissions like there were on the 186 engines? Something about the vacuum port being on different sides of the throttle butterfly.

Hi Nav
Your weakest link is the gearbox.You will destroy it sooner than later.
Best option is an auto trannie or a supra 5 speed steel case.The old traumatics wont cut it,T400 may,you will need to then work the transfercase out.
The series transfercase is regarded as one of the toughest you can get,will handle BIG HP,problem is getting a kit to fit a gearbox to it.
My Bro and I both have C4 autos his is a strong alloy head 4.1,mine a 302 Cleveland(stalled project taking up valuable shedspace)
If you can get a transfercase out of a Nissan 720 4wd grab it(early pootrols also possibly run this one,GQ leafsprungs??).They are as tough as nails,bonus is its a remote mount,ie not bolted to a gearbox.It will allow you to run a gearbox of your choice,a jack shaft is needed to connect it up.You will need to build a handbrake,also available as kits from Hilux modifiers.
Front Brakes,get some drums and backing plates of an original 6cyl or Station wagon Series Landy,they are 3" wide instead of 2 1/4",much greater swept area=better brakes
Goodluck
Keep us informed.
Andrew

Originally Posted by LandyAndy

Hi Nav
Your weakest link is the gearbox.You will destroy it sooner than later.
Best option is an auto trannie or a supra 5 speed steel case.The old traumatics wont cut it,T400 may,you will need to then work the transfercase out.
The series transfercase is regarded as one of the toughest you can get,will handle BIG HP,problem is getting a kit to fit a gearbox to it.
My Bro and I both have C4 autos his is a strong alloy head 4.1,mine a 302 Cleveland(stalled project taking up valuable shedspace)
If you can get a transfercase out of a Nissan 720 4wd grab it(early pootrols also possibly run this one,GQ leafsprungs??).They are as tough as nails,bonus is its a remote mount,ie not bolted to a gearbox.It will allow you to run a gearbox of your choice,a jack shaft is needed to connect it up.You will need to build a handbrake,also available as kits from Hilux modifiers.
Front Brakes,get some drums and backing plates of an original 6cyl or Station wagon Series Landy,they are 3" wide instead of 2 1/4",much greater swept area=better brakes
Goodluck
Keep us informed.
Andrew

I think you will find it was the long wheel base MQ-K that had the remote Tx

Thanks Rovercare
Not up to it on pootrol models,just remember seeing a leafie wagon turned turtle with the remote TX case,thats why I mentioned the leaf springs.
Seen them transfercases used "back to front" in a hybrid off-road racer,nissan twin turbo 3.5V6,they apparentley handle the power back to front just as well as the real way,IMPRESSIVE.
Andrew

What I am wondering is if you are buying the engine for nearly 5k and installing all the dump pipe, adaptors ext... and only running it at 5psi boost. It seems like a alot of trouble to only run it at 30% of its potential, plus if the engine is built for lots of boost then it will be sluggish down low due to the cam being set for a sudden onset of boost.

But anyways it should fit inside the engine bay as you could just get the exhaust manifold manipulated to fit, either by a high-mount or a low-mount turbo all the oil and water lines will need to be fabricated, also the radiator will need attention as it will need more cooling. Fuel will need a fairly good fuel pump so maybe a bosch 040 in tank fuel pump would be a good idea.

Why not just rebuild a standard 202 with a few performance mods, this would be cheaper and probably better for the drive train in the long run.

Dont get me wrong I am a turbo fan, I drive a 1993 Nissan Skyline turbo. And I own 2 series 2 land rovers so I would love to see it done. Now my plan in the future would be to put a Nissan RB30DET or RB25DET with a turbo 5 speed manual gearbox and a toyota transfer case and upgrade to lower ratio diffs or replace the axels with a disc brake upgrade. But eventually it comes down to money and time.