Hey all, I am currently running a DPA gearbox on my 1.8T BAM and want to change the final drive to drop the rev's at 70mph Code Car 1st 2nd 3rd 4th 5th Final Drive DPA Golf 16v 3.3 1.944 1.308 1.029 0.837 3.684 So I thought about using the final drive out of my VR6 CCM Code Car 1st 2nd 3rd 4th 5th Final Drive CCM Corrado VR6, Golf/Vento, Passat 3.3 1.944 1.308 1.034 0.838 3.389 I know this will effect the drive and the gears will be different due to the change of final drive but I want to know how much of a difference per gear vs mph/revs etc...? Any pointers please?
This thread may be worth a read. Have a search to as there has been various discussions on this sort of thing.
Cheers danster that thread is great, Russ did a good job. 3.4 final drive looks like a good option with a Wavetrac LSD. Still need to look at the difference tyres as Russ used Tyre size = 195/50-15 and I use 215/40-16.
The difference in dia of the two wheel/tyre sizes you have stated is as follows..... 195/50-15 = 576mm dia 215/40-16 = 578.4mm dia So not a huge amount in it to be honest, rolling circumferences as follows...... 195/50-15 = 1809.6mm 215/40-16 = 1817.1mm HTH
So the DPA gives me the below Tyre Diameter = 1816.18 mm 1st Gear = 58.26 km/h 2nd Gear = 98.9 km/h 3rd Gear = 146.99 km/h 4th Gear = 186.85 km/h 5th Gear = 229.71 km/h Based on http://www.boosttown.com/gearbox_differential/speed_calculator.php With the CCM final drive its Tyre Diameter = 1816.18 mm 1st Gear = 63.33 km/h 2nd Gear = 107.51 km/h 3rd Gear = 159.79 km/h 4th Gear = 203.11 km/h 5th Gear = 249.7 km/h CCM gear set used a DPA chasing Tyre Diameter = 1816.18 mm 1st Gear = 63.33 km/h 2nd Gear = 107.51 km/h 3rd Gear = 159.79 km/h 4th Gear = 202.13 km/h 5th Gear = 249.41 km/h So does this mean that at 70mph my revs with be lower?
Ah that's great, so all I need to do now is a plotting chart between both gearboxes and look at the power curves. I would assume if the revs are lower in 5th gear I would get higher BHP output. Though this does not concern me as I am after better fuel economy on the local roads really. On the motorway the engine at 80mph sounds like I am revving the life out of it lol. Just thought it best I better edit this post as I need to look at 3rd and 4th gear.
Lol Russ, Brad and I had a chat some time back, I see he's gone down the o2j route. I had the idea about the gear set but had a few running issues to address lol. Did you change the final drive?
His gearset will be the same even though it's 02j . His gearing will be slightly longer due to having 195/45-16 tyres. Which is what I'll have eventually. You can use the quaife calculator to produce some comparison gear speed graphs.
Nice it would be interesting to do a comparison on mine vs Brads/yours setup from a engineers perspective? I've always concentrated on power and took gearboxes for granted!
Thanks I read your thread http://www.clubgti.com/forum/showthread.php?t=235941 Very interesting as I have been building up my knowledge. I am interested in optimal gear change selection with a shift light on the dash as a long term project but it's a pipe dream.
Did a quick calc and theres hardly anything in it with the different size tyres. Gearbox:- DPA - VR FD Tyre:- 195/50-15 ------------------------------------------------------------------------------------------- Top Gear gives 23.796 MPH/1000 RPM and a top speed of 147.536 MPH at 6200 RPM Engine speeds in top gear:- 30 MPH = 1261 RPM 40 MPH = 1681 RPM 50 MPH = 2101 RPM 60 MPH = 2521 RPM 70 MPH = 2942 RPM 80 MPH = 3362 RPM 90 MPH = 3782 RPM 100 MPH = 4202 RPM Top Speed in 1 gear = 37.421 MPH And changes into 2 gear at 3652 RPM dropping 2548 RPM Top Speed in 2 gear = 63.523 MPH And changes into 3 gear at 4172 RPM dropping 2028 RPM Top Speed in 3 gear = 94.410 MPH And changes into 4 gear at 4878 RPM dropping 1322 RPM Top Speed in 4 gear = 120.008 MPH And changes into 5 gear at 5043 RPM dropping 1157 RPM Top Speed in 5 gear = 147.536 MPH ****************************************************************************************** Gearbox:- DPA - VR FD Tyre:- 195/45-16 ------------------------------------------------------------------------------------------- Top Gear gives 24.037 MPH/1000 RPM and a top speed of 149.026 MPH at 6200 RPM Engine speeds in top gear:- 30 MPH = 1248 RPM 40 MPH = 1664 RPM 50 MPH = 2080 RPM 60 MPH = 2496 RPM 70 MPH = 2912 RPM 80 MPH = 3328 RPM 90 MPH = 3744 RPM 100 MPH = 4160 RPM Top Speed in 1 gear = 37.799 MPH And changes into 2 gear at 3652 RPM dropping 2548 RPM Top Speed in 2 gear = 64.164 MPH And changes into 3 gear at 4172 RPM dropping 2028 RPM Top Speed in 3 gear = 95.363 MPH And changes into 4 gear at 4878 RPM dropping 1322 RPM Top Speed in 4 gear = 121.220 MPH And changes into 5 gear at 5043 RPM dropping 1157 RPM Top Speed in 5 gear = 149.026 MPH ****************************************************************************************** Gearbox:- DPA - VR FD Tyre:- 215/40-16 ------------------------------------------------------------------------------------------- Top Gear gives 23.876 MPH/1000 RPM and a top speed of 148.032 MPH at 6200 RPM Engine speeds in top gear:- 30 MPH = 1256 RPM 40 MPH = 1675 RPM 50 MPH = 2094 RPM 60 MPH = 2513 RPM 70 MPH = 2932 RPM 80 MPH = 3351 RPM 90 MPH = 3769 RPM 100 MPH = 4188 RPM Top Speed in 1 gear = 37.546 MPH And changes into 2 gear at 3652 RPM dropping 2548 RPM Top Speed in 2 gear = 63.736 MPH And changes into 3 gear at 4172 RPM dropping 2028 RPM Top Speed in 3 gear = 94.727 MPH And changes into 4 gear at 4878 RPM dropping 1322 RPM Top Speed in 4 gear = 120.411 MPH And changes into 5 gear at 5043 RPM dropping 1157 RPM Top Speed in 5 gear = 148.032 MPH ******************************************************************************************
At the moment on your tyres Gearing Speed ..... 70 MPH 80 MPH DPA STD 3184 RPM 3638 RPM DPA/VR FD 2932 RPM 3351 RPM Drops ~250rpm at 70 and ~285rpm at 80.
Cheers Russ every interesting. I will use the quaife calculator to give me an idea on the CCM gearing in relation to the DPA - VR FD. I guess you are doing the gearbox work yourself?
