I need to know how good/bad the TRex highway manners are? In other words when we travel how easy/hard will it be. We are looking at the TRex right now but we do a lot of traveling to Dallas (180 miles one way). The cam that's in the wife's car right now travels very well and was just wondering how the TRex does. Right now she has a 230/232 .572/.574 111LSA.

 

The t-rex can be great on the highway, just don't skimp out on a good tune.

 

Yeah if we do this we are hoping to be able to make the 500+ mile trip the Thunder and have them tune it.

 

I've made two trips to Bowling Green, one to Austin, and about 7000 miles total, since putting in the Trex in my 02Z06.

Once on the highway and cruising, it gets almost the same mileage as stock and runs just as well.

The only problem I have is avoiding the rpm range where the resonance from the exhaust gets the worst. I either run at 80-85, or downshift to a different gear.

My $0.02 worth!

Steve

 

Holy crap, you're not going to drive all the way there with it untuned, are you? That would make for a miserable trip if you did.

 

I love mine on the interstate. Have had no problems with the cam at all. Definately get 4.10s.

 

Looking at getting a little mail order tune, just to be able to get the car there comfortably.

Unfortunately she does not want to go any higher than 3.73's, although I think I might be able to talk her into a 3.90 when we get her a Ford 9".

 

The cam you have now seems like a good cam, why change? You looking for more power above 5K RPM?

 

"Josh" has a t-rex with 3.90's around here. You may be able to pm him and see what he thinks. But really the 4.10's are great. I think its right at 2000 at 70mph. You need something better than a mail order tune if you are going to keep the 3.73's. Its going to surge like hell. Mine still does a little surging under 1800 with the tune I have now.

 

She wants a cam with a little more umph, and something that idles a little rougher. Plus we just want the mail order tune to be able to get the car from where we live to Thunder (500 miles away).

 

With a mail order tune, you're going to have some pretty noticeable drivability problems, regardless of your gearing. Granted, they won't be as noticeable on the highway as in stop-and-go traffic, but you most likely will get some surging below 2000 RPM.

I have a speed density tune on my car, and even it suffers from some surging in the sub-1700 RPM range, particularly under light load (e.g. steady highway speeds). If you're using the MAF, it's likely the surging would be even worse over a broader RPM range.

Having said all that, the T-ReX is certainly driveable on the interstate, and as long as you keep the RPM around 2000, you shouldn't have any major problems. In fact, I drove my car with the stock 3.23s for nearly a year before installing my 12-bolt with 3.90s. My car's a weekend driver, though, so I didn't have to tolerate the drivability issues on a regular basis.

The bigger issue is going to be the trips around town, when you're stopping and starting on a regular basis.

I would tend to agree to DanZ28. The T-ReX probably isn't going to "feel" any different than the cam you have now. In fact, the T-ReX could seem slightly more sluggish since you'll rarely see 5K+ RPM (at least compared to how often you'll see sub 5K RPM). Quite frankly, I've found myself wishing I had a smaller cam at times to give the car a bit more "umph" at the lower and mid range, since that's where I spend most of my time while driving the car.

Not only that, my car isn't making any more power than a lot of the cars with cams the size of the one you've got now. With all the bolt-ons, I was only able to manage 405 RWHP. My friend with a 230/232 cam made the same number through her locked A4.

Ultimately, though, only you can decided if the swap is right. You could drive the car 180 miles without any "problems," but I seriously doubt it would be a more enjoyable trip with the T-ReX than it is with the cam you have now. You'll have the extra 10-20 HP up top, but at the expense of the drivability problems down low that plague all cams of this size.

Sorry, I answered questions you didn't ask, but hopefully it will prove helpful. And keep in mind, this is all just my opinion. The only car I've ever driven with a T-ReX is my own, so my perspective is pretty limited.

Josh

 

I really appreciate all the input! This is exactly the type of stuff that my wife wanted to read about so she could make her decision on this.

 

when i was 6 speed i had 373's and t rex...around 60 65 the car would buck a little but anything above that will be fine...deff get 4.10's or 4.56's...