Andrew Christian

I had a question, and wanted to see what everyone thought of a forced induction, either super or turbo charger.

My struggle is the speed limiter of the 4.0L engine and if the amount of money would be wasted because of the top speed. I've heard of the top speed being defeated with a tuner but how do you measure the speed past the speedometer?

Thanks beforehand for the info.

flyhigh@mach1

Use a GPS...very accurate.

Arkansas V6

Have a buddy with a turboed 06 v6 pony and it sounds absolutely wicked. I love that turbo whistle along with the v6 engine, to me it just sounds meannnnnnnn. Traditionally superchargers are more reliable than turbos. With a supercharger you have instant power, a turbo has to build up power. And with a new drive-shaft (as our stock 2 piece drive-shafts on the 4.0 have a reputation of destructing above 115 I believe due to the u joints being pressed in with no C-clips((I believe it was from the 07 models forward they began installing C-clips to fix that issue)) but still our drive-shafts are defiantly not the best for high speeds) and a 8.8 axle (stronger and no more 1 wheel peel) you should be able to safely achieve speeds above the 120 on the dash.

As far as your speed, electronic speedometers with a display easily fix the issue of your speed.

(or GPS lol, that would probably be the simplest method.)

tx_zstang

Speed limiter? you have a lot to learn as to why its there and what to do about it.

IMO, F/I is definitely the way to go. Turbo is my favorite and what i'm using now.

Andrew Christian

In what way? The 4.0L have a governor at around 115MPH. You can remove it with a tune but bad things happen at around 120-125MPH. The driveshaft on the V6s don't hold up to terribly well at those stress levels.

I was merely asking the question of what people thought of the 4.0Ls and forced induction. You stated you like your turbo, could you be a little more descriptive than "...my favorite"?

I'm not an idiot, I know how turbos and superchargers work, I'm asking for opinions and what people have done about the limiter.

tigercrazy718

im a little confused about what your asking. you know how the limiter is removed, and that the drive shaft is bad, so if you do those two things youll be "safe" over 120 as long as your tires are rated for that. and it being a waste of time depends on the person. do you want more than 350-400 whp? if so then yea its prob a waste of time. and where do you plan on doing all these high speed runs anyways? if your doing stuff like the standing mile or something then yea the FI will prob be a waste of time bc you wont be able to compete with all the 600+ hp cars that do those.

Arkansas V6

I dont think anyone called you any idiot..... were just trying to help man. sorry if we offended your pride or something?

GrayPony

Replace the driveshaft with a 1 piece, install rubber with the proper speed rating and remove the limiter. Going FI, I suggest swapping the 7.5 rear for an 8.8 with gears suitable for your intended use.

Andrew Christian

No, it was not directed at you. People have a very passively sarcastic way of writing things. But I guess much is lost over plain text.

Anyways, I originally wanted to get people's opinion on whether FI was a waste of time on a 4.0L. I'm not asking how to do it, rather for those who've done it/gone through the process of looking at it, if it was worth it in their eyes.

The portion about the speed limiter was a question that I didn't know the answer to. That was more around how the speedometer read over the 120MPH the stock gauge cluster has. I've sense researched and learned you can install a different cluster, it just needs to be re-calibrated. I am well aware I would need to probably upgrade my driveshaft and defeat the limiter with a tune.

So again, do you guys think it was worth it going FI, for the overall costs?

JimC

I thought it was worth it on my 2006 - added the Xcharger Xtreme, and the car was running mid 12's. Surprised a lot of people at the track (was especially nice beating a Camaro making a lot of noise - he didn't want to talk afterwards).