Manthey Suspension
Discussion
Been looking at sharpening up the suspension on the GT4 to dial out the understeer on track.
Speaking to JZM, they recommended the Manthey Kit: https://www.jzmporsche.com/product/manthey-981-gt4...
Whats people's opinion on the Manthey stuff? How do they compare with the RSS, etc?
Speaking to JZM, they recommended the Manthey Kit: https://www.jzmporsche.com/product/manthey-981-gt4...
Whats people's opinion on the Manthey stuff? How do they compare with the RSS, etc?
I just put full Manthey 3-way KW set-up on my GT2RS
Very, very good - car much better on track than standard (better damped), and still fine for road use, not crash at all.
Only slight downside is squeaking noises, which is standard. Soon drowned out by engine noise, (or even radio if you’re not going fast.)
I wouldn’t waste my time with anything else - these guys test with Porsche on industry days, and sign off every Cup car before it’s delivered to customers. They are the gold standard for Porsche tweaks,
Very, very good - car much better on track than standard (better damped), and still fine for road use, not crash at all.
Only slight downside is squeaking noises, which is standard. Soon drowned out by engine noise, (or even radio if you’re not going fast.)
I wouldn’t waste my time with anything else - these guys test with Porsche on industry days, and sign off every Cup car before it’s delivered to customers. They are the gold standard for Porsche tweaks,
Edited by footsoldier on Saturday 8th September 10:18
I would spend £300 on some rear adjustable monoball toe links and have a track geo done.
Don’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
Don’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
Porsche911R said:
I would spend £300 on some rear adjustable monoball toe links and have a track geo done.
Don’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
This is good adviceDon’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
Steve Rance said:
Porsche911R said:
I would spend £300 on some rear adjustable monoball toe links and have a track geo done.
Don’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
This is good adviceDon’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
I seem to require more adjustment on the front now, based on feel and tyres, so more parts.
not sure that basic Manthey kit will offer you much, bar it monoballs the front LCA ends which should give more feed back, but the kit don't offer any more geo options than you have :-(.
To get that you need the Caster Adjustable Thrust Arm Bushing Kit for the LCA as you are very limited on Camber at the front without having caster adjustment.
hence why this kit was far better, it monoballs all 4 LCA and gives you the caster adjustment needed if you want a real track set up over a fast road one,
very much needed if you go over -2.2 neg front camber. Also as the springs are a bit too soft on the GT4 it seems the DSC box would stop dive and roll with electrics, other wise it's the full on 3 way KW manthey shocks.
Any way every little helps and with you maxing out the geo on that kit now it should feel better over all than how it was.
Maybe JZM will tell you about the Caster Adjustable Thrust Arm Bushing parts while you are there fingers crossed.
To get that you need the Caster Adjustable Thrust Arm Bushing Kit for the LCA as you are very limited on Camber at the front without having caster adjustment.
hence why this kit was far better, it monoballs all 4 LCA and gives you the caster adjustment needed if you want a real track set up over a fast road one,
very much needed if you go over -2.2 neg front camber. Also as the springs are a bit too soft on the GT4 it seems the DSC box would stop dive and roll with electrics, other wise it's the full on 3 way KW manthey shocks.
Any way every little helps and with you maxing out the geo on that kit now it should feel better over all than how it was.
Maybe JZM will tell you about the Caster Adjustable Thrust Arm Bushing parts while you are there fingers crossed.
Edited by Porsche911R on Wednesday 19th September 15:49
northerner said:
I paid £450 for the Manthey kit (2nd hand). I saw the RSS Stage 2 kit (@£1800+) as the next step after the Manthey kit had been fitted and run on a few trackdays this side of the winter layup.
Agree, the Manthey kit is good stage one kit , but only to a point , a point where TDT already had adjustable rear toe links, so unless he fits Caster adjustment parts also he cannot go any more on his geo than he could before. I know he already has the adjustable toe links as I sold them to him :-)So he was at stage 1 already this year. From then it's really the RSS stage 2 kit and the DSC box, Stage 3 being the 3 way Manthey KW set up.
Any way he may come away with extra parts fitted over that kit, time will tell, I hope so other wise he will be back a 3rd time.
Chasing a track geo is a downward slope , then you trailer the car to the track lol
Edited by Porsche911R on Wednesday 19th September 16:28
Porsche911R said:
I would spend £300 on some rear adjustable monoball toe links and have a track geo done.
Don’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
Interested in a source for £300 - presumably the Porsche model you have doesn't change the pricing too much? Don’t spends £1000,s if you are just after dialling out a bit of understeer.
One can spend a lot of money for the manthy named products.
Out of interest what was that stage 1 manthy kit priced at fitted as shown ?
The stage 2 RSS GT4 kit seems to offer more options and looks a much better kit imo
https://www.jzmporsche.com/product/rss-gt4-stage-2...
JZM also does the kit so ask them which seems the best value.
Or as I said at the start spend £300 and see how you get on.
IknowJoseph said:
Interested in a source for £300 - presumably the Porsche model you have doesn't change the pricing too much?
ask C of G for a price off the GT4 CS race car oem parts. the price I guess has gone up from when I got them 3.5 years ago due to the drop in the £ Also TDT will have a spare set going now at a guess.
new ones from RSS are £412 + VAT now.
Edited by Porsche911R on Thursday 20th September 13:11
OK, so.. I went JZM to get my Geo checked over (Was originally setup by CG back at the start of May) since I had done 5 trackdays plus a load of road miles, wheels had been off and on at the OPC for a few service items, so thought it would be a good idea to make sure it still as intended. As part of that initial setup from CG I also had some nice motorsport rear toe links fitted to allow toe adjustment at the rear which would be required to keep the car set-up balanced as we increased camber - both front and rear.
I left CG with a fast road set-up which would also be an improvement over stock on track, so this gave better turn-in than stock, reducing understeer to a point where it wasn't an issue on the road, but also didn’t eat tyres on the road like a full track setup potentially could.
Since that initial set-up where I thought I was only going to do a couple of track days for the year.. I have since done 5 and will end the year probably with 7 or 8, and as I currently don't plan to change the car next year (unless the 718 GT4 is a massive step and I get an allocation, or the bottom falls out of the GT3 Touring market), I am going to be many more track days next year.
Anyway the JZM guys had the car up and did the initial readings…car was still pretty much as set by CG, but it was apparent from the tyre wear and my now revised usage of the car… that I had started to really use more tyre and that understeer on track was an issue.
As has been posted in a few other threads recently.. chassis/tuning shops and people subscribe to various theories about how to achieve a setup and may take different directions to get there.
I gave CG a brief and they delivered on that, and now it seems my brief has changed and so with that, JZM proposed their solution… if I had said the same thing to CG 6months ago they would have advised me to buy more parts at that time also, and in fact they did tell me at the time, that the setup they were applying was about the maximum that could be reached safely without changing parts.
So what did I get…
I got the Manthey Racing 981 GT4 Track Day Suspension Kit - minus the rear toe links as I already had the motorsport toe links (bought from 911R as he has posted).
What do you get in the kit…
- GT3 Cup Control Arm Ends.. Which are longer in the metal casting as well as longer bolts allowing for more camber and safety
- Shims
- Cup Tie Rods which are longer. Stock items limiting factor on how much front camber you can achieve.
- RS Thrust Arms which are longer on the diagonal to the Lower Control arm allowing for more camber and managing caster.
- Brake Ducts to fit the new thrust arms
- New stretch bolts.
- And some little body kit extenders which are supposed to be fitted somewhere but require self tapers into the body work - so I have them but have not fitted them.
All the parts fitted, initial geo applied - road test to get it to all settle a little bit and then back onto the ramps for the Hunter for fine tuning and buttoning up.
As mentioned before, each of these shops have their own view on what is optimal, and also have their view on how open they should be. JZM said they have worked with Manthey to put this kit together, developed it alongside and have insights from them on the correct settings… so I have been asked to not actually post the print out. Personally I don’t have a problem in sharing but I work in the knowledge industry so do understand.
What I can say is this…
Set up from CG that I have posted before was -2.25F, with caster in the early 10s, pretty much zero total toe.
-1.65R , with about .4 degree total toe (in), ARB(M/M)
I now have gained just about an additional 1 degree of negative camber on the front with caster now back in the mid 9s, and almost an additional 1 degree of negative camber on the rear. ARB at the rear is now set to Hard to move the bias away from understeer, ARB at the front remains Medium.
What's it like?…. Well I've only driven on the M25 on the way back home and a bit of B-road blasting over the last couple of days - have done about 80miles on the new setup .. And so far its pretty mega.. The turn-in is totally immediate now and with caster being pulled back a bit, the wheelbase has been shorted a little v the previous setup and the pivot point of the car now seems a lot closer to where I am sitting - immense turning agility and, I haven't pushed hard enough yet - but there is no understeer.
I'm currently running ever so slightly increased tyre pressures on the road to save some wear on the inners with the much increased camber - and try to even out the life of the tyre - so once I can run the car at track pressures this thing is going to be on rails. I can feel the difference even on the road with the rear ARB set to a Hard - on turning the rear is much more eager to come back into play - reminds me a little bit of the X73 from my Cayman GTS - so will be interesting to see - With the GT4, with the medium setting, the car absorbs input throttle and brake, and soaks and settles before responding, the Hard setting has put it on more of a sharper edge.
So in short it sounds like I have gained more turn-in, some more agility and sensitivity - so the thing to observe is how much of a sacrifice has been made in overall stability - I guess I'll find out, and both the car and I will survive to tell the tales.
So what about the RSS stage 2 kit. This would have given me the solid Caster adjustable thrust bushes, however I have achieved a similar result with the longer RS Thrust arms which are mono-balled , and the OEM LCA Caster bushes are eccentric so can be pushed out and adjusted if I ever needed that…also for now, fore-going that completely solid connection saves the car a little bit in terms of harshness and stress on other components over lumps, bumps and British roads. For me the MR Kit and the RSS kits get to a similar point but in slightly different ways with pros and cons to each approach.
The other big this is that that MR kit is based upon Porsche parts, which is kind of cool to me...to just be able to fit factory parts from other cars to your own model to get what you want, and also for warranty and general OPC servicing, these are very unlikely to be recognised as something out of the norm.
If I had have researched this all beforehand, I would have snapped up the MR kit that was for sale here a few days ago - would have saved a bundle, I was almost just going to buy it anyway, and would have sold it on for the same price if turned out to not use it - but I got beaten to it - so, it is what it is.
So, if you KNOW, you want to track or are already doing a lot of track work - so far I'd recommend this kit and set up as a stage 1. If you’re new to the car and not sure what you want - you can do the intermediate setup of a geo and just the rear toe links like I did or just get a set up with no additional parts, until you think you have reached the limit.
Next (and/or Final?) stage for me long term on the suspension front will likely be the TPC DSC module to control damping.
Roll on the next track day, so I can test this set up out fully.
I left CG with a fast road set-up which would also be an improvement over stock on track, so this gave better turn-in than stock, reducing understeer to a point where it wasn't an issue on the road, but also didn’t eat tyres on the road like a full track setup potentially could.
Since that initial set-up where I thought I was only going to do a couple of track days for the year.. I have since done 5 and will end the year probably with 7 or 8, and as I currently don't plan to change the car next year (unless the 718 GT4 is a massive step and I get an allocation, or the bottom falls out of the GT3 Touring market), I am going to be many more track days next year.
Anyway the JZM guys had the car up and did the initial readings…car was still pretty much as set by CG, but it was apparent from the tyre wear and my now revised usage of the car… that I had started to really use more tyre and that understeer on track was an issue.
As has been posted in a few other threads recently.. chassis/tuning shops and people subscribe to various theories about how to achieve a setup and may take different directions to get there.
I gave CG a brief and they delivered on that, and now it seems my brief has changed and so with that, JZM proposed their solution… if I had said the same thing to CG 6months ago they would have advised me to buy more parts at that time also, and in fact they did tell me at the time, that the setup they were applying was about the maximum that could be reached safely without changing parts.
So what did I get…
I got the Manthey Racing 981 GT4 Track Day Suspension Kit - minus the rear toe links as I already had the motorsport toe links (bought from 911R as he has posted).
What do you get in the kit…
- GT3 Cup Control Arm Ends.. Which are longer in the metal casting as well as longer bolts allowing for more camber and safety
- Shims
- Cup Tie Rods which are longer. Stock items limiting factor on how much front camber you can achieve.
- RS Thrust Arms which are longer on the diagonal to the Lower Control arm allowing for more camber and managing caster.
- Brake Ducts to fit the new thrust arms
- New stretch bolts.
- And some little body kit extenders which are supposed to be fitted somewhere but require self tapers into the body work - so I have them but have not fitted them.
All the parts fitted, initial geo applied - road test to get it to all settle a little bit and then back onto the ramps for the Hunter for fine tuning and buttoning up.
As mentioned before, each of these shops have their own view on what is optimal, and also have their view on how open they should be. JZM said they have worked with Manthey to put this kit together, developed it alongside and have insights from them on the correct settings… so I have been asked to not actually post the print out. Personally I don’t have a problem in sharing but I work in the knowledge industry so do understand.
What I can say is this…
Set up from CG that I have posted before was -2.25F, with caster in the early 10s, pretty much zero total toe.
-1.65R , with about .4 degree total toe (in), ARB(M/M)
I now have gained just about an additional 1 degree of negative camber on the front with caster now back in the mid 9s, and almost an additional 1 degree of negative camber on the rear. ARB at the rear is now set to Hard to move the bias away from understeer, ARB at the front remains Medium.
What's it like?…. Well I've only driven on the M25 on the way back home and a bit of B-road blasting over the last couple of days - have done about 80miles on the new setup .. And so far its pretty mega.. The turn-in is totally immediate now and with caster being pulled back a bit, the wheelbase has been shorted a little v the previous setup and the pivot point of the car now seems a lot closer to where I am sitting - immense turning agility and, I haven't pushed hard enough yet - but there is no understeer.
I'm currently running ever so slightly increased tyre pressures on the road to save some wear on the inners with the much increased camber - and try to even out the life of the tyre - so once I can run the car at track pressures this thing is going to be on rails. I can feel the difference even on the road with the rear ARB set to a Hard - on turning the rear is much more eager to come back into play - reminds me a little bit of the X73 from my Cayman GTS - so will be interesting to see - With the GT4, with the medium setting, the car absorbs input throttle and brake, and soaks and settles before responding, the Hard setting has put it on more of a sharper edge.
So in short it sounds like I have gained more turn-in, some more agility and sensitivity - so the thing to observe is how much of a sacrifice has been made in overall stability - I guess I'll find out, and both the car and I will survive to tell the tales.
So what about the RSS stage 2 kit. This would have given me the solid Caster adjustable thrust bushes, however I have achieved a similar result with the longer RS Thrust arms which are mono-balled , and the OEM LCA Caster bushes are eccentric so can be pushed out and adjusted if I ever needed that…also for now, fore-going that completely solid connection saves the car a little bit in terms of harshness and stress on other components over lumps, bumps and British roads. For me the MR Kit and the RSS kits get to a similar point but in slightly different ways with pros and cons to each approach.
The other big this is that that MR kit is based upon Porsche parts, which is kind of cool to me...to just be able to fit factory parts from other cars to your own model to get what you want, and also for warranty and general OPC servicing, these are very unlikely to be recognised as something out of the norm.
If I had have researched this all beforehand, I would have snapped up the MR kit that was for sale here a few days ago - would have saved a bundle, I was almost just going to buy it anyway, and would have sold it on for the same price if turned out to not use it - but I got beaten to it - so, it is what it is.
So, if you KNOW, you want to track or are already doing a lot of track work - so far I'd recommend this kit and set up as a stage 1. If you’re new to the car and not sure what you want - you can do the intermediate setup of a geo and just the rear toe links like I did or just get a set up with no additional parts, until you think you have reached the limit.
Next (and/or Final?) stage for me long term on the suspension front will likely be the TPC DSC module to control damping.
Roll on the next track day, so I can test this set up out fully.
Edited by TDT on Saturday 22 September 01:00
Sounds a great set up, for a dry track, might be a bit extreame on the road in the wet, one thing of note which you can do your self is that rear ARB on full stiff, I did this and it feels great on the road and on track at 85%,but on track at the limit the cars too twitchy I found as did a few others who tried that option, but it’s 10 mintutes to put it back to middle if you do find that.
Esp down craner at 120 odd.
I would be shocked if you managed to use all that rear camber mind you esp with a stiff setting on the rear ARB. And esp so if you do go down the DSC route which reduces roll.
People who know more then me can advise if one can run stiff on one side of the arb and middle on the other to get a mid setting. I have heard different thoughts regarding this practice.
But imo that would be about right.
I do think this might also give you a tad less traction out the bends again now the weathers getting cooler. Easiest way to test is chalk test the tyres outters do 5 laps and if you have chalk left you have over done the rear. I do expect that will be the case. I have a race pyro you can borrow if you wish also. This is fun on slower bends as you drift out them of course :-).
Be interesting to report on track going forward to see if my comments are close or way off.
Esp down craner at 120 odd.
I would be shocked if you managed to use all that rear camber mind you esp with a stiff setting on the rear ARB. And esp so if you do go down the DSC route which reduces roll.
People who know more then me can advise if one can run stiff on one side of the arb and middle on the other to get a mid setting. I have heard different thoughts regarding this practice.
But imo that would be about right.
I do think this might also give you a tad less traction out the bends again now the weathers getting cooler. Easiest way to test is chalk test the tyres outters do 5 laps and if you have chalk left you have over done the rear. I do expect that will be the case. I have a race pyro you can borrow if you wish also. This is fun on slower bends as you drift out them of course :-).
Be interesting to report on track going forward to see if my comments are close or way off.
Yep, that rear ARB is the only part I have a bit of reservation on, you can really tell the difference, so I wonder about it, and most people end up back in the middle, but I’ll give it a try and hope not to stack it, or cause any lasting or serious damage. If I build up speed throughout the day, like I usually do and drive for the conditions it should be fine though..... trackdays are not competitive, so there is no pressure.
At a guess if I do eventually get a DSC the arb will be going back to middle.
At a guess if I do eventually get a DSC the arb will be going back to middle.
Edited by TDT on Saturday 22 September 11:01
Taffy66 said:
Some people make the mistake of setting the front ARB on full soft to reduce understeer.All this does is increase front outer tyre wear.Its best to stiffen the rear ARB and maybe dial in a bit higher rear height to reduce understeer.
Agreed, I think its universally acknowledged that the front end of the GT cars have tended to be too soft anyways, for pure track. (991.2 GT2 RS & 991.2 GT3 RS now run much firmer spring rates - double iirc). So softening it off with the front arb as well is only going to make tyre wear worse. I’m running stock ride heights on the springs and dampers but it may have come down a little bit overall with the increase in total camber.
With my settings the springs are too soft to prevent against bottoming out over heavy compressions and i do use the car on the road over a lot of b-roads where I live.
Edited by TDT on Saturday 22 September 11:21
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