GenIV Throttle Response Kit or Prefix PCM

[nautoncall]

There are several throttle response kits out there so what has everyone tried? Is the Prefix pcm a better option although more expensive?

[efnfast]

I'm using the TKO package - I thought it was snake oil the first time I read about it but I absolutely hated the DBW response so figured I had nothing to lose. Set to 30% it's a night-and-day difference. In theory it should just re-interpret how far you're pushing the pedal, but in practicality it feels like it does more (i.e., WOT with it plugged in at 30% vs WOT with it at 0%/removed feels completely different).

I have the mopar pcm and had initially thought about the prefix pcm, but ultimately didn't go that route because I didn't want to have to go to the dealership to have something re-synced (I think it was the throttle bodies?) and from reading other people's posts their tune seems to cause the throttle to hang open on deceleration (I think it has to do with how they tune decel to get more popping)

[SRT BILL]

I also have the TKO unit on my gen 5 for about 2years now. It does make a noticeable improvement.

[nautoncall]

I know there are a few out there besides the TKO but it seems like that’s what most are using. I read about the pedal commander too.

[nautoncall]

There are two TKO.. which one?

https://tkomotorsports.com/product/2...-response-kit/

https://tkomotorsports.com/product/2...-response-kit/

[efnfast]

I think the first one includes a mounting bracket whereas the second does not. I didn't use my mounting bracket since I didn't want to drill into the car since I wasn't 100% certain what was behind it so I just velcro'd it in place.

[13COBRA]

I loved my TKO response kit in my Gen IV. It was perfect.

[TheMadMachinist]

I have had the TKO units on both my Gen 4 and 5 for about two years now. Just like ennfast I too thought they were snake oil. Now I wouldn't run a DBW vehicle without one.

[bluesrt]

i have never had a throttle response problem on a stock car,what am i missing?

[13COBRA]

i have never had a throttle response problem on a stock car,what am i missing?

The DBW system in the Vipers is known for a lag. Until you drive a Viper with the anti-lag kit on it, you wouldn't know yours is so bad.

It makes a huge difference.

[OvenMan]

What do you plug it into?

[efnfast]

What do you plug it into?

plugs in to your gas pedal (and gas pedal connection plugs in to it)

[Steve M]

The DBW system in the Vipers is known for a lag. Until you drive a Viper with the anti-lag kit on it, you wouldn't know yours is so bad.

It makes a huge difference.

Terms matter, specifically how "lag" is defined.

By my definition, it is the time between the driver pressing the gas pedal and the engine responding.

By that definition, the TKO unit does NOT affect lag in any way, shape, or form. There isn't even an argument - it is an objective fact.

I'm making that bold statement because I don't want anyone to get the impression that it does and end up wasting their money like I did.

The lag is a function of the PCM's programming. The TKO unit does not alter the PCM's calibration, and by that fact alone I can stand by my assertion that it does not affect the lag.

It is also somewhat affected by the mass of the clutch (flywheel + pressure plate) - switching to a lighter weight assembly does help, but that base amount of lag is still there.

It is most noticeable off idle. With the engine idling, stab the gas pedal and take note of how long it takes the engine to actually respond. Some have guessed it's on the order of 200-300 msec, possibly more. You can adjust the TKO throttle response knob to 100% and that lag will still be there.

The only way to change the amount of lag is by changing the PCM calibration. It can't be done with HPTuners without throwing the car into limp mode. The Prefix PCM is supposed to help, but I have no way of verifying.

To those that disagree, bring me verifiable data that shows otherwise.

[Steve-Indy]

Steve, it's been awhile since playing with my original wiTECH and laptop setup..so, I could be wrong in advancing this premise. But as I recall, the laptop display basically looked like an Excel spread sheet...where one could could see many, many sensors come to life upon pressing the gas pedal. It should have been easy to see the pedal position sensor on a Gen IV react, then time the "lag" to RPM rise. Such a shame that they stopped supporting that basic platform...though it may be even easier now with the Micro pod 2.0 which I do not have. Jack B may be able to add some info here.

I may try something along this line later this spring with a stock 08 and a stock 10.

[SA Heat]

The lag makes heel-toeing a little more difficult to get perfect but has never bothered me that much. To me it just feels like a car with a heavy flywheel (as Steve touched on above). I've driven throttle cabled cars that are similar or even worse.

[Aevus]

The lag makes heel-toeing a little more difficult to get perfect but has never bothered me that much. To me it just feels like a car with a heavy flywheel (as Steve touched on above). I've driven throttle cabled cars that are similar or even worse.

Really?
why is that?

[SA Heat]

Really?
why is that?

Turbo lag for starters. It's like delayed throttle response on steroids. I've also had some carbureted cars over the years that didn't exactly have great throttle response. Bottom line is the throttle response on my Viper doesn't bother me enough to do anything about it.

[Aevus]

Turbo lag for starters. It's like delayed throttle response on steroids. I've also had some carbureted cars over the years that didn't exactly have great throttle response. Bottom line is the throttle response on my Viper doesn't bother me enough to do anything about it.

oh, okay I understand now.

So nothing to do with the Gen 1-3 Viper's

[efnfast]

Turbo lag for starters. It's like delayed throttle response on steroids. I've also had some carbureted cars over the years that didn't exactly have great throttle response. Bottom line is the throttle response on my Viper doesn't bother me enough to do anything about it.

I can understand turbo lag but every carb'd vehicle I've built has fantastic throttle response ... sounds like your tune and/or engine combo and/or throttle linkage setup sucked.

I have 18 cars and I can say without a shadow of a doubt the gen 4 viper DBW response is worst than a gigantic sack of donkey dicks - I honestly would not have bought the car if I had test driven it first it is so horrible.

I know in theory something like the TKO/JMS unit should only re-interpret the pedal position so it makes it seem like you're pushing it more than you are, but I have a night-and-day difference when I have the unit plugged in versus removed for throttle response at both light and full throttle.

[SA Heat]

I can understand turbo lag but every carb'd vehicle I've built has fantastic throttle response ... sounds like your tune and/or engine combo and/or throttle linkage setup sucked.

I have 18 cars and I can say without a shadow of a doubt the gen 4 viper DBW response is worst than a gigantic sack of donkey dicks - I honestly would not have bought the car if I had test driven it first it is so horrible.

I know in theory something like the TKO/JMS unit should only re-interpret the pedal position so it makes it seem like you're pushing it more than you are, but I have a night-and-day difference when I have the unit plugged in versus removed for throttle response at both light and full throttle.

Yeah, I'm referring to the old days when I had street/strip builds with too much manifold (i.e. tunnel rams) and big stall converters that accentuated the delay in everything. It's probably the turbo cars I've owned that have made me numb to whatever some don't like about the Gen 4 throttle. It's never bothered me.

[nautoncall]

So this ABSOLUTELY this makes a difference. I did an unscientific experiment today where I went and first drove my TT GEN3and then went to drive the GEN4 without installing the TKO. The TT was on the lowest setting making 750 ish. It does have some lag but still not bad. I came back then drove the TT again against the stock no TKO. I then installed the TKO. In 1st and 2nd gear is makes night and day difference. 75 is too touchy and so far I like 50. I can roll in the throttle from a start and if I want to get on it and spin the tires, all I gotta do is put my foot in it and then shifting into second it takes off like a rocket. Look forward to playing with it some more.

I’d love someone with a vbox to do a 0-60 with and without.

[nautoncall]

Where did everyone install the control knob? Pics if possible.

[13COBRA]

Where did everyone install the control knob? Pics if possible.

I don't have a picture of it..but I mounted mine above the air vent on the left side of the dash.

[nautoncall]

I don't have a picture of it..but I mounted mine above the air vent on the left side of the dash.

So left of the steering wheel? Also, what setting are most of you guys using? I think I like 50% the most.

[13COBRA]

So left of the steering wheel? Also, what setting are most of you guys using? I think I like 50% the most.

Correct. I ran mine between 50-65% ish.

TKO.jpg