Autoblog Q&A: Erich Heuschele from SRT answers why the Caliber SRT-4 is FWD
Posted Nov 29th 2007 5:01PM by Sam Abuelsamid of AutoBlog.com



While the new Dodge Caliber SRT-4 was in the Autoblog Garage, I had a chat with Erich Heushele and Kathy Graham from Chrysler. Erich is the Vehicle Development Supervisor at Chrysler's in-house tuning group and Kathy is a communications rep for the team. We talked about some of the mechanical changes involved in transforming a Caliber into an SRT-4, including why it doesn't have all-wheel-drive.

Autoblog: I just have a few questions about some of the things that your team did on the SRT-4 that differ from the standard Caliber. What sort of suspension and brake changes were made? Also, why is there no all-wheel-drive?

Erich Heuschele: Sure, well I will try to see what I can give you. We dropped the front end 28-mm and the rear 22-mm. We actually have shorter dampers on the car so it has more jounce travel. We didn't just lower the car. We actually got back some of the jounce travel we lost. It has 210-pound per inch springs in the front, 240 in the rear. That's pretty stiff, and on car like the Caliber and the Patriot, they like stiff springs. The base Caliber is more like a 160 pounds per inch and the old SRT-4 Neon was 175 in the front and 125 in the back. We've got 19 by 7 ½ inch cast wheels, 225/45-19 tires. The Goodyear Eagle RS-A or the F1. The RS-A is actually a really kick *** RSA, it's nearly as capable as the F1 tire.

EH: We did extensive tuning on those things. So you are not really giving up much performance with the four-season tire. The brake system is using the 5.7L Charger cop car calipers. It is actually the export 300C 5.7L pads and the cop car brake pads will go on. You could buy those from Mopar. Those are a little more track capable.

And then the rear brake is essentially a Sebring rear disc set up. We've got a unique master cylinder. It's quite large, and we have got pretty damn stiff calipers and I think a pretty good pedal feel out of that thing. I think especially for a slider (floating calipers), I think that is the benchmark brake system.

AB: Yeah the pedal feels a lot firmer than the standard Caliber that I drove before.

EH: Yes, that is totally a different animal. It has got a much bigger master cylinder to push the fluid volume because we've got twin pistons on the front. We have a unique ABS tuning, unique ESP tuning for the vehicle, but suspension wise we maintain the Caliber R/T 24-mm front sway bar. We bump the rear sway bar from a 15 to an 18 mm.

AB: The SRT-4 only has front-wheel drive versus the all-wheel drive that is available on the R/T. What was the reasoning there?

EH: Well, the all-wheel R/T system is really a reactive system that isn't capable of putting anywhere near the torque that we would want to put on the back of the SRT-4. (This statement got a little jumbled in the transcription process.)

So, we would have had to develop a whole new system, which was quite prohibitive and the feeling was that if we had started from scratch with an all-wheel drive performance system in order to compete with the Evo and the WRX STI, we couldn't offer the vehicle at the kind of price point that we wanted to offer.

AB: The R/T all-wheel drive, is that a viscous coupled or electronic clutch?

EH: They have a clutch, but a clutch off the PTU but it doesn't have the torque capacity in the lower gears that we want. And we wanted to be able to run torque capacity especially at time when it is low MU-type system, where okay, if you put a lot of torque to it on the front wheels and it spins up and then we send some torque to back and then as soon as you have traction you're front-wheel drive again. We didn't want to do something like that. We want to run 60 or 70% of the torques to the back tires.

AB: Right, that makes sense.

EH: A real performance system.

AB: You said you did some specific tuning on the stability control for this vehicle for the tires and suspension and the other changes. Were there any other hardware changes that were done on SRT-4?

EH: Let's see. Well, you know we have got a unique full 3-inch exhaust system. I mean if you want to get started in the engine stuff. But, chassis wise we've got, yes, it is definitely a completely unique ABS/ESP tune for the vehicle. And we pushed the limits quite a ways out there compared to a base car. In other words, if you drive through the slalom smoothly, as fast as the car will go, we were 68 ½ mph through the slalom. You will not get ESP intervention.

AB: Yeah, I noticed it seemed to be pretty hard to get it to kick in and I just tried a couple of maneuvers on the road, just a couple of lane change type of maneuvers and it didn't seem to kick in. When I did get it to kick in on a slippery road, it was much smoother than some of the other systems that I have tried on other vehicles recently.

EH: Well, thanks. We do a lot of development work on it and SRTs, I think, generally performance drivers don't like the ESP controlling what they are doing so we try and push it out as far as we can and still catch the car.

Kathy Graham: And that is what I was going to say, Sam, is for that SRT customer, it's a unique customer from the base Caliber. They are looking for different things when they drive the car than the average driver and as Eric said better than I can but that's why we do those things with SRT.

AB: I just have one last question about the engine. You are not using direct fuel injection on there are you?

EH: No, it's not a direct injection. It is multi-port.

AB: Are there any plans in the future if you can talk about it to go to a DI system on there?

EH: We can't talk that. Kathy is shaking her head.

KG: We'd have to kill you Sam!

AB: That's what I figured the answer would be, but I had to ask anyway.

KG: We always are looking at different things. But until we announce something, we cannot talk about it. We look at all technologies all the time and would evaluate it based on what makes sense for the vehicle, for the customer and for the business case.

AB: Sure, I understand that.

KG: Sorry.

AB: Well thanks for answering the other questions.[/align]

 

"because they dont want their cars to reach their full potential" should have been what he said.

i like the new srt4, but it should have been awd...there is no excuse for it not being awd. cost, design problems, all nonsense...find a way to compete with the evo and the sti...along with endless other vehicles.the AWD cars dominate the sport compact world.

 

Aaaaaaagggggrrrrrreeeeeeeeeeedddddd.....

 

lets review the cars that dominate the sport compact world..

the evo...awd, 4 door.
the sti...awd, 4 door.
the skyline (not really a compact, but every ricers dream car, so the mags always cover them)...awd, 2 door.
the record 4 cylinder car at nopi...a RWD DSM.
the record street tire car at nopi...AWD talon.
the supra (again, not a compact, but like the skyline) rwd, 2 door


i know that the srt4 is fast, and while the *** car ran 7s, ive never seen an srt4 in person run better than 10s, but ive seen evos DRIVE into the track and run 9s (the AMS car)...and curt brown got his into the 10s with the stock turbo...i saw him right after he got it in the low 11s, without getting into motor work.

the mopar engineers must not have owned tricycles, so they didnt learn at an early age that FWD sucks.

 

Agreed. I mean, would it have been that difficult to work out some kind of deal with, say, Mitsubishi, and use a "stripped" version of some previous generation EVO all-wheel drive system (like the Mitsu AWC for example)?

 

Although I am a FWD fan, AWD is the only way to go with this class. His excuse is lame. The reason is it could cannabalize the sales of the other SRT models is the real reason I'm sure. Dumb idea. If they beginning to take sales away from the other SRTs, then update the others to where it is so much better that they will except nothing less than the larger SRTs. They would gain more by being able to compete against the evo in terms of brand image than what they could possibly lose by doing this right in Chargerand Challenger SRT sales (which I don't think a turbo I4 is going to affect that much as I wouldn't consider a Caliber for one single minuet no matter how reasonable).

Also, so what if the AWD system isn't asgood as the others?A little less even is better than nothing atall.

 

it would be great to get Erich Heushele away from Kathy Graham
and ask him a series of questions
about the differences and improvements
in the SRT designed 6.1 Hemi V8
vs
the standard and coming models of the 5.7 V8

I would also bet
that Erich & his co-workers could lay out what MPG improvments could be done
to give 'real' MPG gains in the various Dodge models.

Especially valuable would be info
on simple ways to reduce the aerodynamic drag of each Dodge model.
It is almost impossible to know the 'aero tricks' without a wind tunnel
but once known, most of those aero tricks can be done surprisingly cheaply.

 

Just another line of excuses and b.s. from Dodge...... I completely agree with what BadStrat, 03NeonRT, and 97 3.5 Intrepid said..

If this was all they could come up with, almost 2 years AFTER the release of the Caliber......I'll pass on it..

 

Ok, while I do agree that I would like to see a AWD Caliber SRT-4, I also see that you've all missed the fact thatDodge,(and GM and Ford),is working their way toward the AWD/RWD sport compact segment. They didn't even have an AWD offering in their car lineup (minivan excluded) until a year or two ago, and now its available on, I think, every car they sell. (Yes, I know there was the Stealth R/T with AWD, but it's been gone for a long time, and it exceeded that 'affordable' price point that i'll get to in a minute.) And you keep comparing the SRT-4 to the Evo and STi, which as far as I know have ALWAYS been AWD. The Evo and Sti drivetrains have been developed and improved over the past how many years, and you expect them to just come up with a performance- and cost-competitiveAWD system over night?Come on, be realistic.

Dodge has also been showing alot of RWD and some AWD concept cars the past few years. I need to mention here that I REALLY hope they produce that Demon concept, ecspecially for the supposed 15K base price point. Also note that the other two American Car Manufacturers have no AWD sport models.And, while F*** (excuse my language there) does have a RWD so-called affordable sports car, aka: the Mustang, GM only just came out with the RWD Solstice/Sky. And GM's only other affordable sporty car, the Cobalt SS, doesn't even offer AWD on a non-SS model like the Caliber does on a non-SRT model. Oh, and by the way, when I say affordable I'm thinking around $30k, $35K MAXimum, for a current model year. And that's still more car than I could ever afford. I only mention this it response to your mention of the Skyline and Supra. You can't justify comparing a $20K-$30K to a $40K+ car, the upcoming GT-R that is supposed to start at about $70K.

And now I have to bring up something that has been pissing me off for a while now. Ford has their ads about the AWD Fusion, which is not a sports car, but more of a comparison to a Subaru Legacy. They say that in a consumer comparison test of some sort that it beats out the Camry and Accord in performance and the fun-to-drive factor. Well considering that the Camry and Accord are both FWD it damn well better! After all, isn't that what this discussion has been all about: AWD/RWD is better than FWD.

In closing, all I'm saying is be patient. American car manufacturers have always been behind the Japanese, andwe will eventually get to where they already are. I am a loyal Dodge owner, and I'll wait for them to build an equivalent to an Evo or STi before I buy a Mitsubishi or any new ugly Subaru.

Oh, and if you have a different opinion, I really don't care what you think, but if I've stated something as fact and I'm mistaken, please do correct me.

 

you wouldnt buy a mitsu? are you familiar with GEMA? before the SRT models, some of the fastest chrysler vehicles made since the muscle car era ended were made by mitsubishi, for dodge...sadly, dodge hasnt built many cars in the last 30 years that would outrun the mitsubishi built plymouth laser, eagle talon, or especially thedodge stealth rt/tt...

maybe mitsubishi should start making more vehicles for dodge.