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Discussion Starter #702
I need your input guys, girls, steers and queers. 😂

I would kindly ask you to post your thought on dedicated, high end packaging for our beloved GMS parts. Right now I still use cartel packaging system. Packing the GMS parts in to the boxes, from all the left over packages I can find and then taped to death to make sure somethign doesn't get lost or damaged. Honestly, I think it is great not to produce any more waste than we already do and reusing old packaging. It does it's job twice, no additional cost, kind of eco. It's just the looks that bothers me.

Well the question is. Would you be willing to pay about 20€ extra per order to get your parts in super nice, brand new, clean design, dedicated GMS package. I would love to move on and set a new standard. For me getting a +3k€ exhaust in a shady box is wrong, but in the end, I throw the packaging away anyway and only care about the product. Still it feels nice to open a brand new box of goodies though.

So what's your thought? Thanks...
 

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As long as the packaging safely protects the product, you are always welcome to recycle a box when sending something to me!

The only reasons that I would say otherwise would be:
  • ran out of boxes - don't hold my shipment up because you haven't been online shopping lately! :p
  • the part is too fragile to leave bouncing around in a generic box shape.
  • you have to fill a big recycled box with Styrofoam peanuts, meaning that I have a different disposal issue at hand! :)
  • shipping is higher on the generic recycled box because that was bigger than it needed to be, or stuffed with newspaper/peanuts adding to the weight.
Other than that, save a tree for me (you can tell I'm a tree hugger - I drive a 4C :D )
 

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Discussion Starter #704
Another year of ownership of our beloved Alfa Romeo 4C. A year that was a big step forward for us. We raced entire season of Time Attack Italia. Dream tracks, strong competition and tough challenge. We designed, engineered and released a few important performance aftermarket parts for 4C, and launched official website. It was a very tense and colorful year. Let's see what the future brings...

It is my honor to share this premier with you first. (y)

 

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Discussion Starter #705 (Edited)
As some of you probably already know, we are currently fully focused on developing an adjustable ARB / swaybar kit for 4C. Recent engineering studies have provided us some useful info that will allow us to engineer the GMS ARB's beyond what is currently available on the market. Here are some insights...

Stock rear ARB torsional stiffness is roughly 66 lbs/in or 12N/mm. There is also some loss due to endlink angles, but let's neglect that at the moment for easier understanding. So if you are running, let's say my spring rates which at the rear are 456 lbs/in or 80N/mm, which is a decent track spec. and on a stiff side for backroad racing or more honestly, as stiff as you want to go not to let your car fly over all the road irregularities, then adding stock rear ARB, would during cornering provide additional 66/2 = 33 lbs/in or 6N/mm of spring rate. That means only +8% percent increase in effective spring rate (spring + ARB). That only applies during cornering. During acceleration or braking the car will squat and dive just as much, regardless of the ARB stiffness.

If you are running stock spring rates which are incredibly soft for a sports car at 200 lbs/in or 35N/mm, then adding stock ARB would during cornering provide additional 66/2 = 33 lbs/in or 6N/mm of spring rate. That means +17% percent increase in effective spring rate (spring + ARB). That only applies during cornering. During acceleration or braking the car will squat and dive just as much, regardless of the ARB stiffness. Now compared to the upper numbers, 17% increase in spring rate during cornering is more noticeable.

So, the harder springs you run, the less the ARB will help. So why run ARB at all if you can just run super stiff springs? Well if you are strictly track focused and perhaps even run aero, then stiff springs are the way to go. This way you will keep the body roll during cornering, nose dive during braking, squat under accelerating under control and it will also prevent the car to be negatively effected by the created downforce which can cause car to bottom out at high speeds. This way you will also allow left and right side of suspension to work independently, allowing the car to absorb the bumps and curbs much better than with ARB. The the main reason that race cars do run ARB is that they can be quickly adjusted to suit sudden changes in track conditions. You simply cannot afford to change complete alignment and springs for the final of your run if you know the rain is coming, but it only takes a few minutes to adjust the ARB. In 90's most of DTM race cars featured "on the fly" adjustable ARBs that could be adjusted in the cockpit during driving, by the driver via a a lever that changed the angle of the ARB leverage and therefore the stiffness.

So you're not racing and you do not plan to tune the ARB every trackday. Should you run ARB? Probably yes. If you want to keep your car streetable, decently comfortable and still have less body roll during cornering, then ARB is the answer. To keep the car comfort over bumps and other road irregularities you need soft spring rates which on the other hand will allow excessive body roll during cornering, so the only solution is ARB. Your car will be decently soft over bumps or more precisely, when both of your wheels will hit the pothole or other irregularity and decently stiff during cornering as the effective spring rate will be increased by the ARB torsional stiffness. The car will still nose dive and squat just as much as it did before ARB, but it will have less body roll during cornering. There are also some negative effects. With ARB, your suspension will be more dependent left/right which means when you will hit the pothole or curb with only one wheel, it will also effect the other side, making the car twitchy. If the ARB will be very stiff, compared to the stock spring rates, then the dampers (rebound) won't be able to absorb all the additonal spring force that has been generated by the ARB, so the car will become twitchy as well.

There is no universal setup that will yield best of both worlds of comfort / performance, but toying with ARB and spring rates can get you the desired results.

Overview of the facts:

  • No ARB will provide ultimate grip due to independent movement of left/right suspension
  • ARB will bind left/right suspension movement making car twitchy when only one side of the wheel will hit the irregularity
  • Too stiff ARB on stock suspension will cause improper damping settings and therefor twitchy car
  • ARB will provide less body roll without sacrificing the comfort
  • ARB allows quick change in spring rates and can be easily adjusted on the track conditions and layout of the track
  • ARB does not cure nose dive on braking and rear squat on accelerating
  • ARB allows quick change of the effective spring rates
  • Stiffer front ARB = more understeer
  • Stiffer rear ARB = more oversteer
  • Stiffer the spring rates, the lesser the effect of ARB
  • 4C has unusual long leverages of ARB, so the effective spring rates are not effected by ARB as much as with other cars
Render of GMS ARB:

84325994_10222582320055119_6011149194264313856_o.jpg
 

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Thanks GMS.

Question about your rendering though. I've been trying to imagine this on the car since you mentioned the issue. The stock one is flat against the underside of the trunk, isn't it? At least there is some silver insulation right above it which I assume is at the level of the base of the trunk.

This image is not the stock bar, but sits in a similar position.



You show a jog upwards in the middle, which (if it is to clear your muffler - this is where I get fuzzy because I haven't mounted the exhaust yet) must go up into the space above that insulation. There really isn't much vertical clearance for that jog.

What am I missing?
 

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On my previous car (VW scirocco with mag ride suspension) when I upgraded the ARB's it was a massive difference --> It was like a different car (I used H&R arb)
On the alfa: with stock suspension when I upgraded the ARB's the difference was not that big --> I upgraded from OEM ARB's (front and rear) to innokinetic ones that I believe are the thickest.
Maybe the innokinetic material is not that stiff or I don't know but I expected for a bigger change.
 

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Discussion Starter #708
Thanks GMS.

Question about your rendering though. I've been trying to imagine this on the car since you mentioned the issue. The stock one is flat against the underside of the trunk, isn't it? At least there is some silver insulation right above it which I assume is at the level of the base of the trunk.

You show a jog upwards in the middle, which (if it is to clear your muffler - this is where I get fuzzy because I haven't mounted the exhaust yet) must go up into the space above that insulation. There really isn't much vertical clearance for that jog.

What am I missing?
You have a very good eye Kevin. Insulation is about 5 cm lower than trunk itself. The insulation is there to keep the heat from the exhaust from heating the bottom of the trunk, but after few runs engine bay is boiling so the trunk gets hot anyway. 4C is no cold beer delivery car for sure. :D

We have 2 options. To ditch the insulation completely or to press it up a bit to allow for ARB clearance. There is no other way. As this is not an essential part and exhaust and ARB are primary thing, this shouldn't cause too many worries, correct?

I also got the idea to make a removable, portable trunk case on the wheels, like traveling case you take on the plane, that could be removed from the trunk and driven to the grocery and then simply put back in the car. You could also remove it on the track as it is quite heavy (+5kg) and engine would cool much easier by allowing the air to pass from the engine bay through the rear bumper grills. But not now...

On my previous car (VW scirocco with mag ride suspension) when I upgraded the ARB's it was a massive difference --> It was like a different car (I used H&R arb)
On the alfa: with stock suspension when I upgraded the ARB's the difference was not that big --> I upgraded from OEM ARB's (front and rear) to innokinetic ones that I believe are the thickest.
Maybe the innokinetic material is not that stiff or I don't know but I expected for a bigger change.
This explains the fact up above: "4C has unusual long leverages of ARB, so the effective spring rates are not effected by ARB as much as with other cars".
 

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Discussion Starter #709 (Edited)
Something extraordinary for the break from all the CADs and test fitments of ARB. At the moment we're printing the final prototype of rear ARB. By now, numerous changes of ARB design were made, to make sure it will be engineered to the very last detail. We have also booked CNC bending machine for the production of the rear ARB in the upcoming weeks. We are advancing forward...

Ah yes, the break I was mentioning. In the future we plan to build a high end Alfa Romeo 4C crate engine with supporting engine map. We plan to work on stock ecu. I believe there are some of you who doubt or are not so sure about us, so here is a bit of insight of what we know about engine building. This engine here was fully built and assembled by GMS and is one of the strongest in our country and among the strongest BMWs out there. Engine mapping is not polished yet, but you get the idea. We want to gain some high rpm power and torque and lower torque a bit in the mid range as 900 Nm is pretty wild ride. All this is achieved on BMW S50B32, 3.2 liter, straight 6 engine, with 1.5 bar of boost. 1.5 bar is what stock 4Cs are pushing, but the head flow on 4C's are nowhere near what reworked S50B32 is flowing, so I believe there is a lot of room for improvement on 4C engine. The GMS 3'' exhaust on 4C is properly flowing now, and the biggest gains and the most smart move from here on would be the head porting and cooling, so you get the idea where our next focus will go. Can you imagine that kind of numbers, 605HP and 900Nm in 4C? I'd rather not. 💀 I'd say about 350 - 400hp and 500Nm from non stroked 4C engine would be glorious. I am not too keen on stroking 4C engine as it already feels more like a diesel with low and mid range torque. I'd prefer higher rpm powerband with highest possible rpm limit for a hydraulic lifters. I'd say about 7.500rpm and a nice BW EFR TS turbo that would deliver nice and linear power through mid and high rpm range. OK, enough of dreaming. Here is the GMS BMW S50B32 Z3 coupe engine dyno. :cool:
 

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Discussion Starter #713
You can trust me on that. It will be super light, race spec, but recommended only for expert users as the super thin paper sheets will be easy to tear during wiping and leave your hand brown. Use with caution!
 

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^Not sure if my scrotum likes carbon fibre too much....

I also got the idea to make a removable, portable trunk case on the wheels, like traveling case you take on the plane, that could be removed from the trunk
I've had this idea as well, or actually, my girlfriend kind of. Her note was that it was a hassle to take luggage in and out of boot when staying at a hotel for the night. Because you cannot use bags if you want to utilize as much of the boot as absolutely possible, and you need to pack in/out at the parking. She thought of a custom hard case that fit perfectly, but I immediately thought of making a box that can be removed completely with ease. Might require a custom "bonnet holder" pin, maybe going the other way, instead of into the boot.

Since its a lady thing, I guess you could charge about 1 million dollars without a problem.
 

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^Not sure if my scrotum likes carbon fibre too much....


I've had this idea as well, or actually, my girlfriend kind of. Her note was that it was a hassle to take luggage in and out of boot when staying at a hotel for the night. Because you cannot use bags if you want to utilize as much of the boot as absolutely possible, and you need to pack in/out at the parking. She thought of a custom hard case that fit perfectly, but I immediately thought of making a box that can be removed completely with ease. Might require a custom "bonnet holder" pin, maybe going the other way, instead of into the boot.

Since its a lady thing, I guess you could charge about 1 million dollars without a problem.
Oh, just wrap in Gucci Leather or LV synthetic and you will easily get $2.5-$3 million :p
 

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Discussion Starter #716 (Edited)
The COVID-19 situation has some benefits. With the spare time we have on our hand by staying at home and not attending day jobs, we can focus big time on 4C performance parts developement.

Our new GMS 3" exhaust is performing above expectations. The backpressure is immensely reduced, improving response, quicker turbo spool, better flow and far less heat. Dyno numbers are good. Next step is increasing the air flow into the IC and we have a nice solution on the way. Those of you who have seen the new Maserati prototype that is based on 4C has done exactly the same. So yes, it is good to know we are thinking the way other engineers are. I'm proud of that. So what is this part? It is a side scoop for rear flank, entirely made of carbon and modeled the way it fits perfectly on the flank. Super light with increased cooling and as a bonus, aggressive look. We expect first batch to be available within next few weeks. Just a bit of sneak preview for you and more on that later...

received_571018393760550.jpeg received_203946614225691.jpeg received_889310584839188.jpeg
 

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Discussion Starter #717
P.S.: We are also developing carbon rear hatch to replace the stock rear window and allow all the air that comes into the engine to exit as well. We expect big improvement in terms of cooling by these two upgrades. This will allow us then to work on HP.
 

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The COVID-19 situation has some benefits. With the spare time we have on our hand by staying at home and not attending day jobs, we can focus big time on 4C performance parts developement.

Our new GMS 3" exhaust is performing above expectations. The backpressure is immensely reduced, improving response, quicker turbo spool, better flow and far less heat. Dyno numbers are good. Next step is increasing the air flow into the IC and we have a nice solution on the way. Those of you who have seen the new Maserati prototype that is based on 4C has done exactly the same. So yes, it is good to know we are thinking the way other engineers are. I'm proud of that. So what is this part? It is a side scoop for rear flank, entirely made of carbon and modeled the way it fits perfectly on the flank. Super light with increased cooling and as a bonus, aggressive look. We expect first batch to be available within next few weeks. Just a bit of sneak preview for you and more on that later...

View attachment 105574 View attachment 105575 View attachment 105576
You followed my suggestion!! :love:
Carbon parts

Just kidding. Guess when we talked about it at your place, you already had his one in mind.
Way to to!! Looks wonderful!

Any updates on your TCU and ECU mods?
 

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Discussion Starter #719
As mentioned, we can read and write TCT and ECU but other than that we haven't been working on it much as my car is disassembled at the moment for developing of other parts. I expect to release TCT and ECU remaps for GMS 3" exhaust later this year.
 

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At this point, there is an opportunity to touch on something that is very disturbing to me at 4C .The design of front airflow for engine and AC cooling is completely missed so it is not a good idea to increase the downforce in the rear but in the front. There is too much lift in the front now, so I think that a concrete front modification is needed first. My thinking is shown in the attached pictures. What is your opinion?

Stock design:
View attachment 103384
Modification option:
View attachment 103385
Airflow under the body seems to have been the idea in the first sketches:
105582
 
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