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Beginning phase

3K views 15 replies 5 participants last post by  silver06hemic 
#1 ·
As you guys are probably more knowledgable on my cars parts and what works best than myself I have come to seek advice. I own a 2008 Chrysler 300C and the only mod I have is a spectre cold intake. What other modifications can I do to see horse power gains without needing to be tuned. I plan to change out the exhaust to a borla with an h pipe but as that requires a tune in figure I will wait until I get a this twin throttle body and spacer. Please advice me
 
#2 ·
The best set of mods you can do for the HEMI are:

1. Cold air intake
2. Freer flowing exhaust
3. A programmer
4. A 180 degree thermostat

With more air in and more air out, the engine will make more power and may prove to be more efficient. The programmer is a handheld unit, such as the DiabloSport Predator or InTune, which optimizes the engine's air/fuel and timing settings.

The 180 degree thermostat will open earlier than the stock unit, reducing the normal engine coolant operating temperatures. However, the thermostat will be rendered much less effective without having the programmer, which will allow you to adjust your cooling fan settings to take advantage of the lower temperature coolant.

Those modifications are a system and the sum of their contribution to engine power and torque is greater than their individual contributions.

Good luck!
 
#3 ·
Oh, the exhaust mod won't require a tune.

A twin throttle body with spacer will not do much, if anything, for your performance on a stock engine. Your stock throttle body capacity is more than sufficient for your engine. Tests on a lightly modded engine with a TB spacer and without showed no appreciable difference. I suggest you save the money you would spend on those two items for something that will work, such as the intake or programmer which have proven to be solid performance improvements for the HEMI.
 
#4 ·
Thank you sir I appreciate the advice. That thermostat sensor will come in handy since my check engine light came on for about a week when I first installed it then it went off. So in order of best mod to buy next I should buy the exhaust then? And am I able to install the exhaust on my own or does it require some welding. I noticed in the instructions it said I was but that's not always true. Furthermore when I get the tuner do I need to have my car dynoed or does it come preloaded? What's the best tuner I can get for my money the trinity looks nice but it's just so pricey.
 
#6 ·
Do the exhaust next.

Whether or not you can put it on yourself depends on 1) your skills, 2) your available tools - one side of the stock system will have to be cut to remove the stock muffler, 3) which system you buy.

The tuner I'd recommend is the Diablosport Predator or InTune. You don't need to dyno the car with this programmer as it comes preloaded with several tunes you can use right out of the box.

The Trinity is nice but if you don't need real time monitoring, get the cheaper Predator or InTune. All three Diablosport programmers have the same tunes, data logging features, ability to download/upload custom tunes, etc...
 
#5 · (Edited)
Please save your money and skip the throttle body spacer. There are absolutely no gains to be had from adding one to your engine. Throttle body spacers are in the fender-bearing and headlight lubricant category of car parts. While a throttle body spacer can potentially add a few horses to a carbureted engine, by providing a bit of "tunnel ram" effect, it adds nothing to our throttle body controlled, fuel injected engines.

A Diablo Predator tuner is the best bang for the buck mod you can do to these cars. Its the only mod that will give you an honest 15 to 20 horses for under $300. You can find used ones for even less. The tuner comes with several "out of the box" pre-configured tunes. I would wait on a dyno, or custom tune, until after you have a few more mods, such as after the exhaust. A free flow exhaust can usually provide a couple of extra horses with a custom tune.
 
#9 ·
I know quite a few Dodge truck HEMI owners, including me, who tried the Bully Dog and hated it.

I have not heard from any 300 HEMI owners on the Bully Dog and I haven't tried it on my car. I have a Predator loaded on both my HEMI's and have gotten good results.

A used Predator will be quite a few bucks less than $300. If you buy used you really need to know if. 1) It is "un-married" from the vehicle it was on - they can only be loaded on one vehicle at a time, 2) that the data cable and power cable comes with it, and, 3) it is a model # U-7135.
 
#13 ·
So now I have my bbk headers, custom mid pipes, slp loud mouth 2 cat back, spectre cold air a throttle body and throttle body spacer cus I found it for 60 bucks. Lol. And a 180 thermostat plus it's dynotuned I'm pushing 335 hp to the wheels and 363 torque. What is next in my quest for more power is it smart to go ahead and just do my ported heads, cam and forged Pistons or should I just go ahead and go supercharger the one I am looking at is the p1sd1 by procharger and then they can do a meth kit which will have me over 600 to the crank probably more.
 
#14 ·
Well...

First off lose the TB spacer and sell it for $60, you will gain back the 5hp you left behind in putting it on and you'll have $60 more than you have right now. ?

Personally I'd do the blower, keep it at a sensible 5-6psi and have fun. If you have the money which it sounds like you do then do the heads and cam and let the hemi breath.

Don't focus too much on numbers... Its times that matter. I'm modded like you're going to be and run (too high to be safe) 7.5psi and honestly the hp means little... Its the 11.5 in the 1/4 mile that makes me smile... I think 600 crank is possible, but you'll be happy even if it's a little less I guarantee it!

Sent from my VS986 using Tapatalk
 
#15 ·
But bro.. I already bought it. Lol. So headers and cam then redyno it is cus I really didn't wanna dump the 8 grand for the supercharger yet anyway. Lol. I saw in an engine masters video they were pulling about the same. What ported headers and cam shift do you recommend?cus I know nothing about either one. But after those I should be pushing around 400 rwhp and 475 to the crank.
 
#16 ·
Cam is dependent on future mods, if you are supercharging down the road then don't get a great big high lift cam with tons of overlap as you'll bleed boost... Get something that generates tq without being huge and lumpy...

IMO I'd talk to a vendor like HHP or Modern Muscle and see what they recommend based on future mods.

Either way gains from mods are not always 'stackable', as in a cam is 30hp, 40hp heads, 30hp, headers, 20hp intake equals 120hp increase... In reality... If you do all those mods and gain 100hp you'll be damn lucky or you have an optimistic dyno.

Gen 1 non eagle cars, heads, cam, headers, intake and exhaust typically do 350-380hp on dynojet dyno... Like I said... Don't read too much into numbers...

My car was right at 380ish whp when I out a hurt on a 412hp charger, difference in dyno, air etc...

A cam and heads will wake your car up either way...

Sent from my VS986 using Tapatalk
 
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