Autoblog Q&A: Erich Heuschele from SRT answers why the Caliber SRT-4 is FWD
by Sam Abuelsamid on Nov 29th 2007 at 5:01PM 
Click on the Caliber for a hig-res gallery of the 2008 Dodge Caliber SRT-4
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 ass RSA, it's nearly as capable as the F1 tire.
Find out what else changed and why the SRT-4 is front-wheel-drive after the jump.
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.
Reader Comments (Page 1 of 2)
Samantha 5:21PM (11/29/2007)
Father Dieter's last attempt to prove his utter contempt for American's and their beloved Chrysler
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Adam 5:13PM (11/29/2007)
"Well the all-wheel R/T system is really a reactive system that isn't capable of putting more anywhere near the torque that we would not want to put on the back of the SRT-4."
Is that English? Or am I correct in stating that nothing makes sense about that statement?
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sw 5:39PM (11/29/2007)
That statement made no sense to me either. You'd think even a rudimentary awd system would be able to put more power to the ground because the available traction is split up more effectively. He could've just said it was to cut costs, which makes a lot more sense to me.
Adam 5:46PM (11/29/2007)
Looking at it now, I think he was trying to say that the existing RT AWD would not be able to handle the amount of torque they wanted to put out and that developing a new AWD system would be too costly to the consumer.
I guess I'm led to believe if you can't construct a sentence you can't construct a car?
naggs 7:49PM (11/29/2007)
things have a way of sounding right when you say them, with the appropriate inflections and what not, and it doesn't always carry over well into written text.
policyvote 12:46AM (11/30/2007)
Made perfect sense to me. Let me paraphrase:
"The base Caliber AWD system exists to keep Mom from sliding off the road in snow. Niether the hardware nor the software can handle rapid distribution of 250+ ft. lbs. of torque to the rear wheels, like you'd want and expect from an SRT car. We'd rather be valedictorian of the FWD class than the dunce of the turbo-four-AWD school, so there you go."
Peace
policy
Dinger 5:18PM (11/29/2007)
Looks are a toss up, not as bad as the Aztek... not as good as a '87 Corolla FX16. But performance and utility wise it's tough to beat at the price from an objective view. But since most car purchases are subjective... I look forward to some big incentives on this little rocket.
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happycat 5:20PM (11/29/2007)
The springs aren't that much stiffer when you consider the fact that the caliber is a fat ass compared to the neon srt4. He didn't mention they were linear rate either so you're still going to get some body roll. It just seems they stuck whatever will fit from the mopar parts bin to make the car feel sportier.
Chrysler was stupid to stop making ACR variants, you knew you were getting a car that was ready for track duty, particularly because they modified them to be competitive within specific SCCA classes, not some watered down car mildly tuned to feel like it had performance for the sake of marketing.
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Jeff 5:29PM (11/29/2007)
You know, in 1990 Chrysler had a great looking 190 HP turbocharged and AWD coupe. They had no trouble making more HP than these SRT-4s, and could actually put it all down to the ground. And it was cheap.
Can anyone guess what I'm taking about?
It's really a damn shame that they didn't continue to improve that platform over the years.
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brad 5:35PM (11/29/2007)
no, actually i have no idea what your talking about since the calibur srt rakes in at nearly 100 more hp then the mystery car that makes more hp than the srt's
Joe K. 5:45PM (11/29/2007)
Talons, Eclipses, and other DSMs don't have nearly the power this SRT does from the factory under warranty... And if you start putting more power out of the early DSM's AWD systems they broke pretty quickly too, this is a totally different car, for better or worse...
David(Postal) 5:45PM (11/29/2007)
I had one of these as my first car as a senior in high school.. although mine did not have all wheel drive. These are the DSM turbo cars: Eclipse/Talon/Laser. I had the 1990 Plymouth Laser turbo, which was only available in FWD. I loved that car so much, but I was too young of a driver to really appreciate it. I was excited when I saw the Neon SRT-4, it really seemed like a spiritual successor to these cars but the new Caliber just seems so fat to me. I think the above poster means the engine could handle tuning of more power but I am not so sure about this I am not an expert. Its hard to find a car with the sporty simple styling of the Laser I had. http://www.dsm.org/
kenneth 5:45PM (11/29/2007)
here's a clue - it's also associated with a company that also makes TVs.
EquinsuOcha 6:11PM (11/29/2007)
But they did, or at least Mitsubishi did. It later became the Galant VR-4 and it's called the Evo now. The new upcoming RalliArt Lancer is the car that the SRT-4 aspires to be. But that doesn't make it a bad car.
It just means that the people who have been perfecting the AWD turbo four banger are continuing to make amazing cars. They just work for Mitsubishi.
why not the LS2/LS7? 6:50PM (11/29/2007)
The AWD version wasn't particularly cheap and had very little trunk space, as the load floor had to be raised a lot to accommodate the rear diff and such.
The AWD system was rudimentary, but did serve quite well for stoplight races. Like the system discussed here, it was a part-time auto-engaging system and although it was fast for its day, it didn't reach the levels of response we reach now.
I wanted the car, but like all teenagers when the car came out, I couldn't actually afford it. I could barely squeeze the turbo into my budget and even then the insurance put it beyond reach.
I liked the motor, but this motor is a lot more powerful out of the box.
I loved the "power bulge" on the hood.
If you liked that car, get a Mazdaspeed 6. It's similar in a lot of ways and is actually cheaper in inflation adjusted dollars than the Talon TSi or Eclipse GSX ever was.
Jeff 7:31PM (11/29/2007)
@brad
> the calibur srt rakes in at nearly 100 more hp then
> the mystery car that makes more hp than the srt's
The DSMs had no trouble making a reliable 280 HP (with a little tuning). With another 17 years of development and the types of parts this Caliber SRT-4 has (3" exhaust, etc), who knows...
@Joe K.
> And if you start putting more power out of the early
> DSM's AWD systems they broke pretty quickly too
Absolutely not true. The drivetrain on the DSMs was very stout. Granted, the shifting feel was pretty poor and the transfer case sometimes slowly leaked fluid (later recalled because of this) but they had no trouble putting down lots of power. They had a viscous center diff to transfer power to the rear and you could order them with a limited slip diff in the rear end as well.
The powertrain and drivetrain on these cars was exceptional for the time. Mitsu continued to develop it into the system in the universally praised EVO. Chrysler completely gave up on it, and now complains that they'd have to develop a system from scratch or wouldn't be able to deliver it at a lower price point. That's dumb.
naggs 7:59PM (11/29/2007)
oh please,
upgrading dsms to 280 hp was easy but everything except the engine starts to break. the clutch would go first, if that was upgraded and you had tires that actually let you put the power down, then everything else would go.
half shafts, trans and diffs, all made to handle 210 hp and not much more.
doing a 4k dump in a 250 hp awd dsm with stock drivetrain and reasonable sticky tires all but guaranteed you were getting towed home
unreliable above 230 hp, not that they were particularly reliable to begin with
Jeff 8:30PM (11/29/2007)
@naggs
I'm not going to argue details with you since you obviously have zero first hand experience with DSMs. I owned one (hence my fanboism!) and so I know first hand that you couldn't be more wrong about the drivetrain being fragile.
Sadly, what you said about the rest of the car not being particularly reliable is true. :)
That's totally beside my point that Chrysler should have continued developing that powertrain and drivetrain (as Mitsu did). Instead, they're now lamenting their lack of a suitable low cost AWD system.
BTW, I'm not trying to knock what they've done with the SRT-4, but I won't buy one that's FWD. If they'd have coupled that powertrain with AWD that would have been a real game changer. Just like it was back in 1990.
Spankee 8:42PM (11/29/2007)
Sure they did, the last gen Evo had the same engine as my '97 Eclipse GS-T did. Your 17 years of development was called the Evo IX.
Dan Parmelee 5:37PM (11/29/2007)
RS-A a competent tire? Ha, what a joke...that tire loses a lot of comparison tests by Tire Rack to stuff costing less. Why OEMs keep picking that tire is beyond me.
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