Tune to turn a 930 Turbo into a 934

[vonMarshall]

Hello tuners…

I am in the process of building a fleet of 930 Turbos to race against each other in Custom Races in a sort of 1980’s style revival bringing cars together from different racing series.

The power and weight across the group will vary a little bit, some will be 1150kg and others 1250 with more power, to represent cars that raced in Gr.4, Gr.5 and American spec. They will all be c650pp and have different ways of getting power, for instance some will be bored up, some will have higher rpm turbos, some will have semi racing exhausts whilst some have full racing exhausts and manifolds. All will use RH.

What I am hoping to find is a suspension and lsd tune (feel free to move ballast around and tweak the break balance and aero) that maximises the stability and ease of driving these beasts for both me and the AI.

I do like Priano’s tune for road tires and find this car a joy to drive already, but seeing as I will end up with nearly $10m worth across 20 cars, think these deserved a bit more thought from those of you who fancy your tuning skills sets.

I will very happily put in a lot of test laps at Spa, Watkins Glen, Interlagos and Suzuka so if there are several tuners out there who want their tunes benchmarked I would be happy to put them to the test.

Eventually I will let the AI loose with your tunes so we can see what PD think of them too.

Hope some of you tuners take up the challenge!

 

[Meythia]

Edit: this comment small for follow up reading.

 

[vonMarshall]

It like to add one, wide body and rims installed:
View attachment 1248616
View attachment 1248617 View attachment 1248618

Nice! I’ll give it a go. I do have a challenge for you though.l it has to have the standard wing which removes the downforce! Yikes!!

 

[Meythia]

Nice! I’ll give it a go. I do have a challenge for you though.l it has to have the standard wing which removes the downforce! Yikes!!

Both front and rear I assume then?
Ill try to rebalance it

 

[vonMarshall]

Both front and rear I assume then?
Ill try to rebalance it

Unfortunately you are stuck with zero on the rear. You can go to 100 on the front with the Type A front which is what I use for 934s, but when I tried it I found that made the car very unstable

 

[Meythia]

Unfortunately you are stuck with zero on the rear. You can go to 100 on the front with the Type A front which is what I use for 934s, but when I tried it I found that made the car very unstable

Adjusted to the rules of rear aero.
Not a regular user of LSD settings, Im eager to see how much better it can be with other entries.

 

[vonMarshall]

I’ll get stuck in tomorrow night and put 10-20 laps in at Spa. Will feed back! Excited to try it out.

 

[Meythia]

I’ll get stuck in tomorrow night and put 10-20 laps in at Spa. Will feed back! Excited to try it out.

Here is my reference lap on Tokyo, I used that track for one because I know it upsets RR or rear heavy cars and for the other because I can somehow keep them almost fast there
I dont have too much of practice on many of the other tracks, so I simply hope the setup will carry over and not be the burden that the car was without LSD, also this is my first time ever using LSD at all. Feedback appreciated, maybe I can learn to use it more efficiently

 

[vonMarshall]

Hi Meythia

So I have started the testing.

To begin with I decided to ignore PP and just set the same weight and bhp for all attempts and have also decided to use the same gearbox settings throughout.

My car has the wide body which has been stiffened and given the Stage 3 diet. The engine has the stock turbo, no anti-lag, racing intercooler, air filter, exhaust, manifold, and we also have racing clutch and brakes on board.

As she stands, that gives us just over 650pp for those who are counting.

Brake balance and ECU are left at 0 to start with, the power restriction is 100% so we have 424bhp to play with and I added 106kg to bring her up to the Group 4 legal weight of 1120kg.

I am running at Watkins Glen at sunset, a track I know and love and no pesky rain to throw off lap times.

For reference, I am a high “C“ to low “B” driver on a DS controller.

This gives me the following variables to play with as I tune…

Suspension
LSD
Front downforce (no rear downforce available with a standard wing)
Brake balance
Ballast positioning

Tonight I started with some banker laps, the car with stock suspension, lsd etc to see what we are dealing with. I do love my Porsches and have done more miles in them than any other car so far, and my driving style suits them, slow in - fast out and ideally predictable understeer.

I did 20 laps, the first 5 working out braking point, then 10 nice consistent ones, then 5 really pushing it. My fastest lap was 1:54.400.

Driving at 95%, it was reasonably easy to get mid 1:55’s but the moment I went for the last 5% I really started to notice wobbles under braking, over-rotation as I accelerated out of slow corners and a lack of predictability at high speed though the esses as you come out of the first corner and up hill. There was a real unwillingness to turn in, and in my last 5 lap, although I recorded 2 sub 1:55’s, I also ruined 3 laps, 2 of them losing a couple of seconds trying too hard at the chicane and one with a full 720 spin adding 9 seconds to the time!

So in conclusion I feel the stripped out 930 is a gem of a car and I hope to find some pace as we strap on the fully customisable suspension and LSD and play with ballast and break balance.

I‘ll report back later this week when I have the time to do 20 laps with your tune. Looking forward to it!

Nice Tokyo laps BTW! Don’t think I’ve ever driven there in the sunshin!

 

[vonMarshall]

Adjusted to the rules of rear aero.
Not a regular user of LSD settings, Im eager to see how much better it can be with other entries.
View attachment 1248941
View attachment 1248942View attachment 1248943

Hi Meythia,
I must have put 100 laps in at Watkins and Spa... she is very fast!
But I am struggling with predictability and I seem to be able to do 3-4 great laps but then, out of nowhere, the nose bites under breaking and she catches me by surprise.
I have been playing with the LSD and have reduced Initial down a lot which seemed to settle the car down a bit.

I then tried Priano's tune which I can get to within about 0.25 per lap of yours but seems to telegraph when it is about to lose grip very clearly, so although I am losing a second every 3-4 laps vs your tune, I am not having the horror lap on number 5.

I am going to have a play around now with a hybrid tune to see if I can retain your all out pace with the gentler handling characteristics I am getting from Priano.

Has to be said I am absolutely loving fettling this car. It is so rewarding to drive and I find myself doing the 5 lap Porsche cup at Spa time after time to bag 90k per 15 minutes of "testing" and when I am feeling brave, I switch out the RH for SS and head to the Nurburgring 1 lap Porsche race there.

 

[Meythia]

I am going to have a play around now with a hybrid tune to see if I can retain your all out pace with the gentler handling characteristics I am getting from Priano.

Thanks for the notice.
Maybe once I get my disc back I might try to tame it down myself, though about the LSD this seems very driver related by preference now, I was slowly increasing the initial torque until it hit the point where I felt most comfortable with.

But I am wondering about the speed difference, in the end I have about the same power (though higher torque by the turbo) all the while your basic tune has a better acceleration on the sheet.

 

[vonMarshall]

I think your set up is tighter up front so when I nail an apex I am carrying more speed. Priano’s tune has downforce front and rear. Because I am using the standard wing I have zero rear downforce. I started by retaining the front downforce that Priano specifies but did not like it. I took it down to zero too and immediately it balanced out. It slides more than your set up so at 100% I am just coming out of corners a bit slower, but on the flip side it is utterly predictable and if I miss an apex or go in a bit heavy, you can just lift and let it tuck in.

I am only a C/B driver and use a DS so imagine an A with a wheel may be able to make less mistakes than I do!

As soon as the 930 is back in the UCD I’m going to buy a load of them and I’ll set some up with your tune and some with Priano’s… let’s see what the AI does with them!!

 

[Carlos Fandango]

@vonMarshall - apologies for resurrecting an old thread, but I wondered what progress you’d made here as I was trying to do something similar, albeit to make grinding the Le Mans race for credits more interesting. To this end, I wanted to create a 934 RSR, and like you, wanted to avoid the rear wing. Equally, because the Le Mans race almost always features rain, it need to not try and kill me every time I turned the steering wheel.

I tried the popular tuner set-ups, but once you peel the rear downforce off, they are sub-optimal. So I went to work and tried to create something that I could drive respectably and consistently. I’m also still playing around with the right combination of mass through weight reductions, ballast to come back up to period regs, and the correct combination of power mods to get the output I need but not lose the Porsche-ness of the sound. I haven’t nailed any of it yet, but it’s getting there, so thought I’d share where I’m at here (since I found this thread while I was researching where to start in the first place). Note that I’ve retained the standard gearbox as I think the 934 was only a 4spd in period. I’m at 539bhp / 1109kg at the moment but 691pp which is higher than I was targeting - likely some of that is from the RM tires, and RH will bring it closer to 650pp. I run -4 brake balance, again to ensure the car isn’t trying to kill me on a regular basis!

As soon as a 930 pops back into the UCD, I’m going to repeat the build but without the bore and stroke kit so that I can maintain the correct engine displacement.

Please excuse the phone pics from my TV - I’m too lazy to try and do it in the PS and then move them back and forth.

Edit: did the third weight reduction and then addd more ballast at the front to get back to 1120kg as you had… much better. Will be using this car in this configuration for a while (until I can build a second one at 3.0l)

 

[vonMarshall]

@vonMarshall - apologies for resurrecting an old thread, but I wondered what progress you’d made here as I was trying to do something similar, albeit to make grinding the Le Mans race for credits more interesting. To this end, I wanted to create a 934 RSR, and like you, wanted to avoid the rear wing. Equally, because the Le Mans race almost always features rain, it need to not try and kill me every time I turned the steering wheel.

I tried the popular tuner set-ups, but once you peel the rear downforce off, they are sub-optimal. So I went to work and tried to create something that I could drive respectably and consistently. I’m also still playing around with the right combination of mass through weight reductions, ballast to come back up to period regs, and the correct combination of power mods to get the output I need but not lose the Porsche-ness of the sound. I haven’t nailed any of it yet, but it’s getting there, so thought I’d share where I’m at here (since I found this thread while I was researching where to start in the first place). Note that I’ve retained the standard gearbox as I think the 934 was only a 4spd in period. I’m at 539bhp / 1109kg at the moment but 691pp which is higher than I was targeting - likely some of that is from the RM tires, and RH will bring it closer to 650pp. I run -4 brake balance, again to ensure the car isn’t trying to kill me on a regular basis!

As soon as a 930 pops back into the UCD, I’m going to repeat the build but without the bore and stroke kit so that I can maintain the correct engine displacement.

Please excuse the phone pics from my TV - I’m too lazy to try and do it in the PS and then move them back and forth.

Edit: did the third weight reduction and then addd more ballast at the front to get back to 1120kg as you had… much better. Will be using this car in this configuration for a while (until I can build a second one at 3.0l)

Hi Carlos
sorry for the delay… I have been away and was lucky enough to get to the Classic Le Mans weekend… so many 934’s!

In the end I went with pretty much the Priano tune but with zero downforce front and rear, same as you. I like where you are going with the soft rear anti-roll bar and will give that a go.

This is my current set-up and like you I have kept the original 4 speed in there for that lazy long turbo spooling.

I love doing the 30 minute Le Mans in this… FM4 will get me 3 laps but means I really have to work for the win, especially if it is a dry race and Heywood only 1 stops. I like to slap on softs and FM1 for the last 4 laps (with a 2nd stop) but cannot always hunt him or Portillo down.

I love this car IRL and in GT7… nothing like a 934 sliding around Terte Rouge and heading off down the Mulsanne as night falls!

 

[Carlos Fandango]

Hey @vonMarshall - well that's some response!! Jealous of the Classic Le Mans visit. Are you also planning to go to Goodwood FoS? I saw that Kremer has restored a Vaillant 935 that will be making the trip. I haven't been for 5 or 6 yrs now (big trip from California), but friends are certainly going.

I picked up 3 new 930 from the UCD yesterday since it's the first time they popped back in. My current 'big motor' car will become a later model IMSA replica I think in Brumos colors, and then the new cars will be:

1. New Le Mans spec with similar set-up as before without the bore and stroke update to Grp 4 specs - either Jagermeister, Vaillant or Elf colors
2. I'm going to do the RSR engine swap on one (because science again) and will likely run that in Wally's Jeans livery
3. TBD

Let me know how you get on with my changes on the suspension. I think they're still the same as when I posted above. Don't forget BB -4!

 

[vonMarshall]

Hey @vonMarshall - well that's some response!! Jealous of the Classic Le Mans visit. Are you also planning to go to Goodwood FoS? I saw that Kremer has restored a Vaillant 935 that will be making the trip. I haven't been for 5 or 6 yrs now (big trip from California), but friends are certainly going.

I picked up 3 new 930 from the UCD yesterday since it's the first time they popped back in. My current 'big motor' car will become a later model IMSA replica I think in Brumos colors, and then the new cars will be:

1. New Le Mans spec with similar set-up as before without the bore and stroke update to Grp 4 specs - either Jagermeister, Vaillant or Elf colors
2. I'm going to do the RSR engine swap on one (because science again) and will likely run that in Wally's Jeans livery
3. TBD

Let me know how you get on with my changes on the suspension. I think they're still the same as when I posted above. Don't forget BB -4!

Good taste carlos!

Unfortunately no GFoS for me this year... have been many times though and really need to book it in. I am only an hour or 2 away and not in California, so no excuse!

I have not been around much to trial your settings out but have some free time this week and will get stuck in. I have been too busy finishing my Schiller Racing Mecarrillos 934 off and making the decals for the 1980 Denver 934.

Do you have a strategy locked down? I typically start on RMs and set FM4 which just about gives you 3 laps and I can get 4:13s with this car at that level. If the race is dry, I then 2 stop, both on RS with FM1 which gives you 2 fast out laps, one fast in lap and so far my best is a 4:06 to bring it home.

 

[Meythia]

Hi Meythia,
I must have put 100 laps in at Watkins and Spa... she is very fast!

So, back after my GT7 vacation and coming back here.
I did a few laps to find back to my form on whatever comparable level that may be, after around 30 minutes I was doing laps of around 1.54.3xx consistenly, though I have to admit, my present self isnt happy with the cars handling right now and I dont know what my past self was thinking configurating it like that ;D

 

[vonMarshall]

Welcome back! I have been experimenting with by base Priano tune and the softening the rear as per Carlos’ tune above… is just as quick but I think I prefer the base tune.. just feels so predI table and Porschey.

Interested in seeing your next version.

 

[Amor]

Hi Carlos
sorry for the delay… I have been away and was lucky enough to get to the Classic Le Mans weekend… so many 934’s!

View attachment 1271014

In the end I went with pretty much the Priano tune but with zero downforce front and rear, same as you. I like where you are going with the soft rear anti-roll bar and will give that a go.

This is my current set-up and like you I have kept the original 4 speed in there for that lazy long turbo spooling.

View attachment 1271015

View attachment 1271016

I love doing the 30 minute Le Mans in this… FM4 will get me 3 laps but means I really have to work for the win, especially if it is a dry race and Heywood only 1 stops. I like to slap on softs and FM1 for the last 4 laps (with a 2nd stop) but cannot always hunt him or Portillo down.

View attachment 1271018

View attachment 1271019

I love this car IRL and in GT7… nothing like a 934 sliding around Terte Rouge and heading off down the Mulsanne as night falls!

Great work
I like tune like this which try to maintain or ricreate real behaviours

 

[Carlos Fandango]

@vonMarshall - apologies for the delayed response. Been very busy with work and other home activities. Strategy is similar to yours and target is to run 3laps at the start on FM4. Weather change has been very strange recently in this race, but if it rains heavily then I'll do 2 laps on IM and then last 2 on RM tyres with FM1 or 2 dependent on how close the "competition" is...

That Meccarillos livery looks outstanding - great work!! I've been looking at other liveries as well (not that I have any skill in that direction) as this car has a pretty long competition history in privateer hands. Anyway, while I got lost in the internet, I found this (if you happen to have a spare $600k)!!

Burton-Kremer 934 for sale

 

[Meythia]

Interested in seeing your next version.

I finally did some changes now and manages to improve lap times by about 0.5s per lap on Watkins - within my very first test laps.
The new setup instantly felt much more stable to me.

Much softer on the back and a bit harder on the front + a small difference in LSD values.
This is as happy as this car can make me I think.