dyno chart for RT

[chillyone]

Found this on Airaid's website. Don't these baseline #'s look low? Maybe someone can provide some insight since I'm not terribly knowledgable about these things (but have enjoyed reading all the posts). I'm now two weeks into waiting period for my orded RT.

[MagnumFreak]

That does look really low. Should be about 290 hp at the rear wheels.

[Herb Jenssen]

The norm is 25% reduction at the rear wheels for automatics so that's about right.

[00DakotaSport]

The norm is 25% reduction at the rear wheels for automatics so that's about right.
Nah, every Magnum/300C i've seen dynoed has had atleast 285hp, its got the mercedes five speed auto, no way its loosin 25%

[tirpitz]

The norm is actually 20% for most auto trans, but the new benz trans looks to be loosing about 25% due to torgue managment issues.

They need to put a t56 in these Hemi vehicles!!!!!!!!!!

[Herb Jenssen]

Nah, every Magnum/300C i've seen dynoed has had atleast 285hp, its got the mercedes five speed auto, no way its loosin 25%

Dakota,
I'm curious. How many 300c's and Magnum RT's have you dyno'd?
Are they customers that just want to know how much horespower that they have at the rear wheels? Are they all similar in HP & TQ?
Thanks
Herb

[Mischief]

heres a pic of my dyno. I had the car Dyno'd on 30th of Oct and these are SAE numbers:273.1 HP and 305.8 TQ
http://www.fototime.com/F64B9AF6687E62C/standard.jpg

[00DakotaSport]

Dakota,
I'm curious. How many 300c's and Magnum RT's have you dyno'd?
Are they customers that just want to know how much horespower that they have at the rear wheels? Are they all similar in HP & TQ?
Thanks
Herb
First off, i never said I personally dynoed any..... no customers, i just check all the boards, like lx forums, and general dodge forums, those people that have had them dynoed see anywhere from 270-290hp from the HEMI and Merc. Tranny, just what i've seen. Do a search, im sure you'll find them.

[faterotong]

seems like it's 20% loss looking at mischief's graph

[Wicked96SS]

Although I am no expert, I have had a lot of time behind the dyno with my old Impala. What I have learned is that they are very difficult to get a real meaningful number. Too many variables including when the last time the dyno was calibrated, the weather, how hot the car was, was the hood up or down, was there moving air over the engine bay, etc. etc. etc... That same car could have made 290 RWHP the next day at the same shop, or at a different shop.

I gave up trying to tune my Impala on a dyno, too many variables to deal with, and in the end, it never is as good as you had hoped.

What a dyno is really good for is to see the difference (like the original post did) in modifications. Even then the variables are just to sloppy.

The best way that I personally found to tune a car was at the track, and then it would usually only be good for that days runs. I am of course talking about the difference of maybe .1 of a second, but I spent most of my time on the laptop changing fuel tables and spark tables and shift points just to get that last .1 out of it.

ANYHOW... just my personal opinion, and to the original poster, I wouldn't worry about it too much.

And, in my experience, parasitic loss from the transmission was about 20 - 25%, again, depending on the variables! ;)

[g3gtsboy]

Looks about right to me. as mentioned previously lots of variables in there. Have no idea what the elevation of the AIRRAID dyno sheet is. Well within margin of error. Besides, the magnum R/T is awesome performance for a full size wagon but it certainly is not a viper. I've never felt like It was a rocket.. The commercials are hype, I've yet to do a burnout like in the commercial. Even with traction control off. The highway gears take the "off the line" performance away. Now an RT with 4.11 or 4.56 would be formidable but it would have a hard time passing a gas station.

[Wicked96SS]

g3gtsboy... I have been thinking that 3.73's would be a good gear for the car... sure, you will sacrifice some gas mileage but might be able to get a quicker launch....

I am sure that 3.07 gears will be available for the RT (might already be), as I believe that is what is used in the AWD RT...

A quick search of the web found this information:
SPECIFICATIONS- 04
TRANSMISSION: AUTOMATIC, 4-SPEED OVERDRIVE
Availability...................................... .................................Included with 2.7L and
RWD 3.5L engines
Description....................................... ...............................Three planetary gear sets, one
overrunning clutch, full electronic
control, electronically controlled torque
converter clutch
Gear Ratios
1st............................................... ...............................2.84
2nd............................................... ..............................1.57
3rd............................................... ..............................1.00
4th............................................... .............................. 0.69
Reverse........................................... ..........................2.21
Final Drive Ratio............................................. ................. 2.7L – 3.90, 3.5L – 3.64
Overall Top Gear Ratio............................................. ...2.7L – 2.70, 3.5L – 2.51
TRANSMISSION: AUTOMATIC, 5-SPEED AUTOMATIC
Availability...................................... .................................Std. RT, included with AWD
Description....................................... ...............................Adaptive electronic control or
AutoStick® driver-interactive
manual control and electronically
modulated torque converter clutch
Gear Ratios
1st............................................... ...............................3.59
2nd............................................... ..............................2.19
3rd............................................... ..............................1.41
4th............................................... ..............................1.00
5th............................................... ...............................0.83
Reverse........................................... ..........................3.17
Final Drive Ratio............................................. ..................5.7L RWD – 2.82, AWD All – 3.07
Overall Top Gear.............................................. ...........5.7L RWD – 2.34, AWD All – 2.55

Stock the RT has 10.12 overall gear ratio in first gear... that is not bad at all... changing it to 3.73 would give you 13.39 gear ratio... wow!! My Impala SS with 4.10's in it would only give me 12.54 gear ratio!! Of course that would change the final drive to 3.09... compared to that of the Impala SS with 4.10's is 2.87... So, yeah... crusing RPM would be higher, and you would get much worse gas milage... oh well, have to give up something to get something!!

Some quick calculations show that at 80MPH a stock RT with the converter locked and no slipping in the trans (theoretical perfect transmission), you should be turning about 2198 RPMs... with the 3.73's installed you would be at about 2907 RPMs.

[g3gtsboy]

Good info!!! Thanks.

[joemagnum]

I have found changing my gears in past cars to 3:55 was the perfect situation. In 3 different cars I gained MPG, better performance etc, however when you beat it, it got alot worse mpg. thing is nowadays you hsve to worry about the gear ratio interacting with the computer or not....

[vwdave]

IMO, there is nothing wrong with the RT's gearing. I believe the Torque Converter's stall speed might be kinda low. At least thats what it feels like to me.

*Shrug*

[Los Lobo]

I had 4 runs done on my car when it had 2,000 miles on it
Same Dyno 265-268 HP to the wheels.
summer time, engine hot, in Jax. Fl.

At 8,000 miles I had it dyno'd at a different Dyno in Green cove springs, cold engine as well as 2 other warm runs. 270-hp..

Two diferent dyno's, two different model and mfgrs and the results are the same.

They said...Jet told them....Jet will have a chip out in 30-days.
They are telling me that The best way for me to get anything like what I want is to spray it.

I was always told that adding Nitrus caused engine failure, due to excesive heat.
Is this true ? :rck:

[Wicked96SS]

No, not at all... adding Nitrous will not cause engine failure... running lean does... if you add nitrous, you need to add fuel. The 2 ways that nitrous increases power is by 1) adding a lot more oxygen into the combustion mixture (N20), allowing you to burn more fuel (wich also needs to be added) and 2) the Nitrogen bouncing around in the combustion chamber will raise the pressure slightly, basicly slightly increasing your compression ratio (that is one way to think about it at least).

Anyhow, where people get greedy is when they add a 50 shot system, and then get used to it, and up the jetts or mess with them to add more nitrous... then run lean, then blow up. Remember, it is the air to fuel ratio where you get the power from, all nitrous does is add more air so you can add more fuel... the latter is what people forget.

As for running Nitrous Oxide on a street car, I would probably not do it... or at least stay with a 50 shot... anything higher, make sure you get a wet system (one that will add fuel). And make sure you know what you are doing.

To do a nitrous system safe and right will cost you in the thousands... but is one of the easiest ways to add power, and (relatively) cheap. You would have a car that would be as fast in a straight line drag race as somebody who spent a lot more money on buliding an engine...

[Los Lobo]

I need another 100-hp at the wheels, at least that's what I want in my mind.
I don't think there is a turbo or super charger for it yet.
The guy's I have working on my speed/quickness problem said NOS was cheap.

[Wicked96SS]

Well, 100 RWHP in a magnum... hmmm... I would bet you would have to get 150 jets for it, and that big a gulp of Nitrous would more than require you to add fuel. To do it correctly, I would add a multi headed fuel pump and have the nitrous fuel supplied by this... then I would get a progressive controler and have it switch on at WOT over 3000 RPMs, and switch off about 500 or more RPMs before you shift. Add to that a fuel pressure regulator, switches that will cut the nitrous if there is no spark, no fuel pressure you are looking at a couple of grand in parts, then the labor to run all of it and test it.

Anyhow, that is what I would do, but I don't want to blow my engine up because I cheaped out on some safety gadgetry...

Best thing is to be safe... you wanna go fast? Spend the money to do it right... or just enjoy the car the way it is right now. It's faster than most... enough to get you in trouble

No matter how much money on invest in making your car faster, there is always going to be somebody faster than you...

[vwdave]

Actually, it can cause a extreme lean condition, which raises the temperatures inside the combustion chambers.

A 100 wet shot used sparingly shouldnt hurt, just dont use it while in 4 cylinder mode. :eek:

[HGB7862]

Somebody was telling me the other day about a turbo boost that actually replaces the muffler??? has anybody heard of such???

[vwdave]

94-2002 Camaro/Firebird guys have been using a new turbocharger design that replaces the rear muffler. The turbocharger sits where the muffler would go. Supposedly it works good, but I personally think its a load of bullshit. I think the lag would be a week long. I am not a expert on this, but I think that the energy is far less the farther you go down the exhaust.

Take that information for what its worth.

[HGB7862]

I am a skeptic as well, Would like to know more about it though and some pricing!!!

[vwdave]

The biggest issue I see with forced induction with the RT is the Displacement on Demand and tuning with it. It would be a damn nightmare. Trying to tune a car that is NA and doesnt have vacumn problems is hard, throw in a forced induction and DoD. :( I am getting headaches just thinking about it. :(

[Wicked96SS]

94-2002 Camaro/Firebird guys have been using a new turbocharger design that replaces the rear muffler. The turbocharger sits where the muffler would go. Supposedly it works good, but I personally think its a load of bullshit. I think the lag would be a week long. I am not a expert on this, but I think that the energy is far less the farther you go down the exhaust.

Take that information for what its worth.

I agree... that sounds like the biggest load of bull I have heard about... could somebody please post a link to where I could read about this?

I just don't see how it would work effectively at all...

[billapex]

Here's the link: Squires Turbo Systems (http://www.ststurbo.com/)
Dunno if it really works well--I'd like to see one in person and talk to someone who lives with it on a daily basis.
There would be no concern about tuning it with MDS, since MDS activates at minimum throttle under cruising. When you press the throttle even a tad, it deactivates. There are two types of tuning: part-throttle and wide-open throttle (WOT), and in both of those instances, MDS would not activate.

[vwdave]

There are two types of tuning: part-throttle and wide-open throttle (WOT), and in both of those instances, MDS would not activate.

On my 89 camaro, to tune the thing there is about 120 points of information to tune. And that car is really straight forward. Thats 16 years of technology improvements we're looking at. Every millimeter you push on the gas pedal puts another point where you have to tune it.

[Dr. Jeckel]

The STS turbo systems really work well. My friend ran 132mph with and STS kit and 100shot of NOS in a manual TA on drag radials. I had an LS1 and was really into modifying it, and then a Buick T-type. There is a dealer here in town for STS kits and numerous people have had them installed. The turbo's impellers and exhaust housings are designed differently than front mount turbos and the deletion of the intercooler actually allows more efficiency. Intercoolers typically rob 1-2 psi of boost because of back pressure and turbulence, but they do cool the intake charge. The pipe running along the underbelly of the car actually acts as a slight intercooler in the STS kits. Anybody who has had turbos, knows lag, and generally no car will make full boost below 3,000rpm. Feeling the boost build is half the fun :) If you want info on these kits, go to LS1tech.com or go to the STS site. There are alot of testimonials and information on these kits. They have a kit for the hemi truck, and I could see them making a kit for the hemi magnum. They have general kits you could buy to make your own system. A 5-6 psi turbo system would be alot of fun and be about the max without doing fuel, trans, rear-end upgrades. Don't take my word for it, just read all about it and make your own decision. I would buy one, if only they didn't void the warranty or if the warranty was up.