Vortech / Diablo throttle response question

[SDChargerSRT]

OK, got my Vortech, love it, runs great.

In regards to throttle response, if I'm in 1st gear, and just ease into it, I can take off like normal without scaring anyone. But if I give it say, what feels like 25% throttle, it breaks the tires loose and takes off like, well, like a supercharged SRT should! But there seems to be a very narrow window of throttle application from 0-25%, and anything above that it seems to want to go all out. And I can't feel much difference from say 1/2 pedal to full pedal. It feels like anything 1/2 pedal or more, and it's at full power.

This only occurs when I have selected 1st, when in normal D it doesn't happen, I think this is because it shifts to 2nd so soon.

Why is this a problem?

Well, honestly, it startled me the first time it happened and I caught the traffic ahead of me WAYYY faster than I expected. And it's a mighty chore to try and use autostick and take off without frying the tires, which is tons of fun but doesn't get you moving.

Is this typical boost behavior? I thought I read somewhere that diablo had a setting for how much the throttle body opened in relation to the pedal position. Could it be this? Can that be adjusted without messing up the Vortech canned tune?

I want to do some track days and autocross, and right now I could not manage 1st gear in a parking lot around tight corners.

[Super T]

You can adjust the map that relates desired throttle to pedal position and make the bottom end less sensitive, yes.

[SDChargerSRT]

Will that effect the Vortech tune in any way?

[Super T]

Nay. Just lets you adjust the sensitivity of the pedal basically. I know when I eventually get the cash to go Roots, I'm going to try to have the pedal give me almost stock power up to about 80% and then just go nuts for the last bit of travel.

[sdcarguy]

The reason you feel the drastic pull is that with vortechs stock tune you are getting a **** ton of timing at part throttle. This makes it very snappy but runs a bit lean till you get into the throttle...At least this is what Lance and I determined when I did the logs for them...

[SDChargerSRT]

So is it bad to run in this "snappy" range because it's lean?

[sdcarguy]

Sorry about the delay in reply...Not lean as your thinking but leaner and more timing. At WOT with the stock tune I was down in the high 10s to low 11s. At part throttle it was closer to 11.5-12 which is not "Lean" but leaner then WOT. Dont worry about this. Just the reason it feels so snappy. Ive learned to roll into it slowly and use this...once you feel that surge if you go from 25-100 slowly you will feel the gains increase

[Heavy H.P.]

Quick ?

Would this be a good thing on the track? If u had a tire on the car and u were getting all the power at once assuming u hook up wouldn't this result in a better 60ft also a faster ET?
I'd like to know how is it getting on the highway from the on ramp do u bearly have your foot on the pedal?

[SDChargerSRT]

No problem on the delay. And good to know we're still in a "safe" range. I figured Vortech had tested all this out, and that's why I went with them because of their reputation.

Heavy HP, It is 100% driveable and well mannered. And, if I leave it in D, there's no issue at all. It's just using autostick, taking off in first, there's not the complete range of throttle application there was without the supercharger, if that makes sense.

For daily driving, drag racing, and full throttle acceleration, it's not an issue. I want to do some autocross, and I think it would be a handful if you were in 1st, in the middle of the rpm range coming out of a corner. It is not a deal breaker at all, if there was some easy way to adjust it I would look into it. If it's due to boost, which it sounds like it is, then I will just go try it and see!

I should probably bring the video camera, as it might turn from autocross to drifting

[sdcarguy]

With better tires and half shafts I would preload the car at about 2000-2500 and not have to worry about building boost slowly.

Getting on the freeway at part throttle is interesting. You can leave you foot in the same place and at about 3000 she leaps

Also my biggest issue atm is mid way through first about 4500 it likes to spin the tires

[YoungMedic23]

Should have gotten a Jeep!

;-)

Ur issues sound like good issues though!

[1362#Sublime]

Its a both the tune and HP. My moded 5.7 needed to the petal pushed past 70% before the car would go crazy. But now I have a 392 and it is acting just like yours in D. If the petal poshion is past 30% it feels like its all out, but you go a head and 100% the petal and you can feel a diff but not much. I think I need to have my tuner lean out the car at WOT there must be power hidding for motor safety. So Im not boosted yet, working on it.

Has anyone eles noticed if you 100% the pettal at sertain rpm the car just seems to bogs,

[sdcarguy]

Yeah would have been great out of the hole but Ill just fix the rear and then I should be good.

Should have gotten a Jeep!

;-)

Ur issues sound like good issues though!

[ET1970]

I had the same problem with my setup in a 300c srt-8 and the gs motorsports supercharger. It seemed that if I tried to get into the throttle to quickly that I would have tons of wheel spin and if it tried to roll into the throttle the engine would lug and shift into second gear to early. The throttle was like an on off switch, making it very difficult to handle the car. I felt the problem came from the way that the secondary injectors are operated. The secondary injectors are non functioning under 2000 rpm. Secondly, the injectors are very large and come on instantly, thus producing torque to fast and making it produce the noted changes in the fuel mixtures. Less than 25% throttle the injectors are off and the air mixture is a little more to the leans side, and then more than 25% throttle the injectors come on and the mixture goes rich.

After I changed to the 426 stroker I took the car to Arrington Engines to get the engine tuned. They removed the piggyback computer of gs motorsports and the secondary injectors. They then installed larger primary injectors. After tuning they were able to get another 77 hp. They worked with Diablo to create the best possible tune for my application. The difference is like night and day. Now the power comes on silky smooth. I can give throttle and spin the tires right up to the rev-limiter and hold it there. Where as before I would hit the throttle and spin the wheel right past the rev-limiter and bang it on and off the rev-limiter not allowing a smooth burnout. As a matter of fact I now prefer not to have the traction control on because the car is so predictable and manageable it works better without it.

So my advice is to remove the secondary computer as well as injectors. Then reprogram the primary ECU. Arrington Engines has developed multiple tunes and works with Diablo to produce exotic tunes for all applications.

[Someguy]

So my advice is to remove the secondary computer as well as injectors. Then reprogram the primary ECU. Arrington Engines has developed multiple tunes and works with Diablo to produce exotic tunes for all applications.

glad you got your problems sorted out. sounds like a nice set up now. but the only reason you had a secondary(piggy back) computer, and extra injectors, is because you had one of the old ghetto GSmotorsports set ups.

the vortech kit, uses bigger injectors as part of its kit. also, they worked with diablo, to develop a tune. and it comes with the kit. so there is no piggy back, to worry about. the OP's issue is strictly related to tuning on the diablo.