NEED ADVICE, TUNING Options for Track Car

[Vladiz93]

Hello,

I have an M4 GTS that is solely my track car. I am looking this year to tune the car but I have a couple of questions?

1. What tune is preferred? Carbahn or VF Engineering? Maybe another one?
- If I were to do VF I would do the Stage 2 set up. But Stage 1 for either if downpipes are not good for the car.

2. Should I down downpipes or just mid pipes? I have heard either side of this.
-
3. Can the car handle a tune while doing this many days a year? Is there anything to worry about engine wise or other parts that it may affect with extra power output.?

The car does around 15-20 days a year on track, I live in Boston. It has Apex wheels on Hoosier R7s as its track set up with M4 GT4 front suspension bits.

I instruct with the PCA.

Thank you,
Vlad

[SYT_Shadow]

Hi Vlad

Congrats on the GTS, it's a great car and a joy to drive on the track. I'm also a PCA instructor, I look forward to seeing you at the Glen!

Do downpipes. The cats are way too close to the engine and have failed in other F8X cars with heavy track use.
I've lost an engine due to melted cats with extended track time and I tell you, never again!

I'm not sure a tune is the best idea. I've tracked a Stage 1 tune GTS (catless downpipes) with 295 R7s and it cannot hook up leaving turns. I'm convinced it would be faster with the stock tune.

The crank hub is a concern for any heavily tracked F8X car especially as you dial up the torque.
I know the ESS Stage 1 tune intentionally limits the stupid midrange torque the engine can produce which is likely the cause of the spun crank hub. BM3 also allows you to limit the torque manually.

I think you'll be fine with most Stage 1 tunes, just ask them for the catless version and no added boost. I stand by what I said though, even with 500whp it can't hook up to save its life.

Carbahn is likely the most conservative (aka longest lasting) tune other than ESS, so I'd do one of those

You'll get plenty of comments from people with 600whp M3s that magically have no issues hooking up and never had a crank hub problem either, however, read through 10 hub threads and notice how many people spun their crank hub a few days after tuning their car and that tells me everything I need to know

[Gomeler]

SYT_Shadow really covers it nicely. The crankhub would be my primary concern, especially if you're as competent of a driver as I'd expect a PCA instructor to be.

I haven't checked S55 tuning options, boost-by-gear in my STI was very helpful. On the GTS I'd go ham on 4th->6th, and maybe add a little peak power to 3rd. Wouldn't want anymore torque or power in 2nd, and the middle of 3rd would be conditions dependent I feel.

[Lienrocs]

I don't think a tune is going to lower your lap times. I've driven a VF stage 1 GTS and it was spinning at the top of 5th gear in 80 degree weather with brand new cup 2's at the proper psi.

[Vladiz93]

Originally Posted by SYT_Shadow

Hi Vlad

Congrats on the GTS, it's a great car and a joy to drive on the track. I'm also a PCA instructor, I look forward to seeing you at the Glen!

Do downpipes. The cats are way too close to the engine and have failed in other F8X cars with heavy track use.
I've lost an engine due to melted cats with extended track time and I tell you, never again!

I'm not sure a tune is the best idea. I've tracked a Stage 1 tune GTS (catless downpipes) with 295 R7s and it cannot hook up leaving turns. I'm convinced it would be faster with the stock tune.

The crank hub is a concern for any heavily tracked F8X car especially as you dial up the torque.
I know the ESS Stage 1 tune intentionally limits the stupid midrange torque the engine can produce which is likely the cause of the spun crank hub. BM3 also allows you to limit the torque manually.

I think you'll be fine with most Stage 1 tunes, just ask them for the catless version and no added boost. I stand by what I said though, even with 500whp it can't hook up to save its life.

Carbahn is likely the most conservative (aka longest lasting) tune other than ESS, so I'd do one of those

You'll get plenty of comments from people with 600whp M3s that magically have no issues hooking up and never had a crank hub problem either, however, read through 10 hub threads and notice how many people spun their crank hub a few days after tuning their car and that tells me everything I need to know

Thank you for that. Can the car handle the Akrapovic catless downpipes without a tune then?

[SYT_Shadow]

Originally Posted by Vladiz93

Thank you for that. Can the car handle the Akrapovic catless downpipes without a tune then?

In theory it would just throw a CEL.

As that is annoying as hell you could also ask a tuner to remove the CEL and leave the rest alone

[Vladiz93]

Originally Posted by SYT_Shadow

In theory it would just throw a CEL.

As that is annoying as hell you could also ask a tuner to remove the CEL and leave the rest alone

Thank you. And with the downpipes, we are looking at minor power gains?

[SYT_Shadow]

Originally Posted by Vladiz93

Thank you. And with the downpipes, we are looking at minor power gains?

I think of downpipes as purely a safety thing, however, you do gain power from it. I think it's around 20whp when you're close to 500whp (stock GTS)

[tom @ eas]

Tunes aren't solely for power. The BM3 tune can be a useful tool for additional purposes like logging, diagnostics via OBD and aid in cooling (option to have cooling fans kick on sooner).

Not much power to be gains from catless downpipes, figure about ~10whp. However it's required when cranking up the boost.

[coryf]

I have an AA tune on my GTS. The "stage 2" was too much for the track imo. Torque hit too hard in the mid range and made rolling into the power on corner exit difficult. It also would foul spark plugs and cause a miss. Tried a few different maps and ended up with a boost by gear setup. Stock power in 2nd with a tad more in 3rd. Full boost in 4th/5th/6th. It had the best drivability and still good peak speed at the end of the straight. Have down pipes and the max psi crank hub fix on my car as well. Spun the crank hub on a damp track with wheel spin with the "stage 2" tune installed.

Honestly the stock power is fine for this car. We have worked on handling issues more than anything. The most recent thing I am going to try is SPL rear toe links so I can add more negative camber in the rear. (the stock links max out before the stock camber does). I have the camber plates up front.

[SYT_Shadow]

Originally Posted by coryf

I have an AA tune on my GTS. The "stage 2" was too much for the track imo. Torque hit too hard in the mid range and made rolling into the power on corner exit difficult. It also would foul spark plugs and cause a miss. Tried a few different maps and ended up with a boost by gear setup. Stock power in 2nd with a tad more in 3rd. Full boost in 4th/5th/6th. It had the best drivability and still good peak speed at the end of the straight. Have down pipes and the max psi crank hub fix on my car as well. Spun the crank hub on a damp track with wheel spin with the "stage 2" tune installed.

Honestly the stock power is fine for this car. We have worked on handling issues more than anything. The most recent thing I am going to try is SPL rear toe links so I can add more negative camber in the rear. (the stock links max out before the stock camber does). I have the camber plates up front.

maybe SPL arms help a bit, but the GTS I'm referencing has MCS 3 way shocks and full SPL arms front and rear

Still can't put power down on a Stage 1 tune with 295 R7s

[Lienrocs]

Originally Posted by SYT_Shadow

maybe SPL arms help a bit, but the GTS I'm referencing has MCS 3 way shocks and full SPL arms front and rear

Still can't put power down on a Stage 1 tune with 295 R7s

There's just not enough weight over the rear axle to be able to get the power down well in lower gears, full stop. Boost by gear is the only option but I don't know of too many tracks where you're in 5th for very long let alone 6th or 7th.

Also, so we don't pollute OP's thread I sent you a pm about the car you're talking about, I have some questions if you don't mind.

[FormulaMMM]

Maybe a silly question, but if you've tracked it, what are you looking to accomplish with a tune? Altered power characteristics? More straight line speed? More power on corner exit ? (Can't imagine...) Throttle response changes?

I'd take your set of goals to each tuner and see if they're certain about being able to deliver without any potential downsides.

GTS has so much power already. Just not worth taking a flyer for another 5-10%. I'd really consider coryf's post above. I think even renowned and competent tuners are going to be up against it improving the engine dynamics and driving experience over stock

[Vladiz93]

Originally Posted by FormulaMMM

Maybe a silly question, but if you've tracked it, what are you looking to accomplish with a tune? Altered power characteristics? More straight line speed? More power on corner exit ? (Can't imagine...) Throttle response changes?

I'd take your set of goals to each tuner and see if they're certain about being able to deliver without any potential downsides.

GTS has so much power already. Just not worth taking a flyer for another 5-10%. I'd really consider coryf's post above. I think even renowned and competent tuners are going to be up against it improving the engine dynamics and driving experience over stock

I want more power out of the corner and straights. The car hooks fine with my set up, just a bit more power to keep up with some other cars.

[SYT_Shadow]

Originally Posted by Vladiz93

I want more power out of the corner and straights. The car hooks fine with my set up, just a bit more power to keep up with some other cars.

What cars are you trying to keep up with?

My stock engined M3 CS is dead heat in straights with 991 GT3s and GT3 RSs. The GTS is significantly faster than the CS, so it should be reeling them in during straights

[Continental02]

Originally Posted by SYT_Shadow

What cars are you trying to keep up with?

My stock engined M3 CS is dead heat in straights with 991 GT3s and GT3 RSs. The GTS is significantly faster than the CS, so it should be reeling them in during straights

I'm very confused by this statement. Any F8x in stock form definitely does not keep up with or pull on 991 GT3s. I was in the same boat as him. You can keep up with almost anything through the turns, but once you hit the straights, they're gone.

Originally Posted by Vladiz93

I want more power out of the corner and straights. The car hooks fine with my set up, just a bit more power to keep up with some other cars.

Do a custom tune, or don't do it at all. I've talked to too many people that have had issues using off the shelf tunes. Whether that be traction issues or reliability issues.

I've tracked with a preset tune and the power delivery sucks compared to what you can get with a custom tune. It's night and day, not even close. You will struggle to put the power down out of corners with a preset tune, even with Hoosiers.

I say do both downpipes and midpipes if you're able to. The power gains are negligible, but the sound gains are what really sells it for me. The car is too quiet with your helmet on. It's much easier to feel connected with the car when you can actually hear what's going on.

[chillindrdude]

I keep up with mediocre to average GT3 drivers without issue.

I would focus in on suspension ( proper camber and toe)
And aero.

[SYT_Shadow]

Originally Posted by Continental02

I'm very confused by this statement. Any F8x in stock form definitely does not keep up with or pull on 991 GT3s. I was in the same boat as him. You can keep up with almost anything through the turns, but once you hit the straights, they're gone.
.

In a straight, the CS is dead heat with a 991 GT3. I run into 991 GT3s all the time in the red run group at PCA and the CS stays with them without issues in the straights.
In the E9X generation they would certainly horizon you as soon as you got to a straight.

I've been doing this a while... there's no point in saying the CS keeps up with 991 GT3s in straights if it does not. And the GTS is more powerful than the CS

[Vladiz93]

Originally Posted by Continental02

I'm very confused by this statement. Any F8x in stock form definitely does not keep up with or pull on 991 GT3s. I was in the same boat as him. You can keep up with almost anything through the turns, but once you hit the straights, they're gone.



Do a custom tune, or don't do it at all. I've talked to too many people that have had issues using off the shelf tunes. Whether that be traction issues or reliability issues.

I've tracked with a preset tune and the power delivery sucks compared to what you can get with a custom tune. It's night and day, not even close. You will struggle to put the power down out of corners with a preset tune, even with Hoosiers.

I say do both downpipes and midpipes if you're able to. The power gains are negligible, but the sound gains are what really sells it for me. The car is too quiet with your helmet on. It's much easier to feel connected with the car when you can actually hear what's going on.

Thank you for that. Do I need a tune with downpipes and a mid pipe?

[Vladiz93]

Originally Posted by chillindrdude

I keep up with mediocre to average GT3 drivers without issue.

I would focus in on suspension ( proper camber and toe)
And aero.

I have suspension upgrades

[Vladiz93]

Originally Posted by SYT_Shadow

What cars are you trying to keep up with?

My stock engined M3 CS is dead heat in straights with 991 GT3s and GT3 RSs. The GTS is significantly faster than the CS, so it should be reeling them in during straights

Just those really. And to catch back up to Cup cars and Cayman track cars.

[Lienrocs]

Originally Posted by SYT_Shadow

In a straight, the CS is dead heat with a 991 GT3. I run into 991 GT3s all the time in the red run group at PCA and the CS stays with them without issues in the straights.
In the E9X generation they would certainly horizon you as soon as you got to a straight.

I've been doing this a while... there's no point in saying the CS keeps up with 991 GT3s in straights if it does not. And the GTS is more powerful than the CS

I'd agree with this. I had no issues catching a tuned GT3 in my run group last time out. I was having some serious traction issues due to some set up difficulties and I couldn't get the tire pressures right plus having a passenger with me. As soon as the car hooked I had no issues other than not getting the point by cause he didn't want to let me through. The car has as much power as it needs, in my opinion. If I were OP I'd try and maximize minimum corner speed and exit speed to get the extra MPH down the straight. M cars shouldn't be point and squirt cars and I think any aftermarket tune turns them from a scalpel to a broad sword.