More power and acceleration!!

[Shelby-Love]

Ok, I'm not sure if this is the appropriate area to ask these questions as I am new to the site, but here goes. I am by no means a gear head, if it doesn't have a USB port on it, I probably don't know what to do with it. So, here's my questions.

1.) I have a 2007 Shelby GT w/14000 miles on it, that is not my d/d, that has a kb sc running about 10psi of boost, that dyno's at 487RWHP. It has a 4.6L engine. That said, I've been told that I am right at the limit of power before I start rolling the dice on breaking something and I show it no mercy when I do drive it, so I know I would. I have heard a few options that I can do to allow me to unleash the power in my kb 2.6L stage 2 supercharger. Namely, 1.) upgrade the lower rotating assembly with a racing tuned and balanced one. Estimated cost $6000. 2.) I was told today to check on mmr.com for something called stroked short blocks, which if I understood correctly (probably not) that the lower part of the motor can be replaced with a stroked and bored lower unit that can get me from a 4.6L to 5.0L-5.2L and allow me to go to a smaller pulley as the one I am using is quite large.

Basically, I guess I'm just asking for opinions as to what is the best way in terms of money, longevity, and speed/acceleration to invest in obtaining more power. I realize I will need to upgrade other items like brakes for instance, but if you know of other things that are a must, feel free to spread your knowledge to someone that wants to suck it out like the antidote is in it (chris rock).

Lastly, Gears. I'm looking for opinions on gears for the rear end and at the moment I'm considering 4.10's as that is what my mechanic runs in his corvette and that is one bad mofo. He said he loves them. I am more concerned with acceleration, like 0-80 than top end if that helps you decide. Any help is appreciated guys. Sorry for being so long winded.

Oh, if you want to discuss on the phone, I'm available anytime (225) 773-3664, just give me a call and I would be honored to talk about it.

[ArkansasMystic]

I'm not familiar with the newer cars, but I think it'd be hard to beat gears for the price.

[adam2kgt]

You are pushing the envelope with that rear wheel hp figure on a stock bottom end. Seems like Shelby would upgrade the engine internals to forged units, but maybe not. I would suggest getting a short block with forged internals. The short block you mentioned, from MMR, is a good choice. Their 950 stroker short block, which increases displacement to 5.0 liters and is rated to 950 hp at the crank) is about $3300 dollars. Yes, a short block is the bottom of the engine, in this case they use a 2003 Cobra block, bore it out, and install all forged internals, including stroker crankshaft, forged Manley rods, forged Manley pistons, and it is all balanced and blueprinted (good thing). You use your existing cylinder heads, intake, exhaust, supercharger, everything except the actual block and internals. Now, this will pick up some power by itself, but combine this with ported heads and good supercharger cams, with a smaller blower pulley and tuning, and you could probably break 600hp at the wheels. Maybe more.

[Blackout_03]

Yeah you are pretty much at the limit of the stock rotating assembly. You really have too options if you want to uprgrade......either buy a built shortblock...faster turn around but cost more...or buying the rotating assembly...crank, rods, pistons and having it done local....takes aot of time but is usually cheaper.

I am going with a built long block myself...it costs more up front but i will have a complete motor to sell to help recoupe some money..plus my car will only be down a weekend to do the swap..not 2-3 months waiting on somebody else to get off there butt and work on my motor.

Theres a bunch of shops that build good motors...MMR, PSI, Strictly Performance, Livernoise.... blah blah....I know livernoise have a high 9 low 10 sec S197 on 20" Drag Radials...so they know there 3v cars. PSI and Strictly are both semi local..south texas...so tunning wont be that bad.

2nd thing...why are you wanting more power? are you getting beat or just want it?........i follwed your build with Kris but am unsure of a few details....do you have headers?...how about suspesion? What gears does your car have now?

The reason im asking is if you want to build a street terror you havethe power now to beat 99% of the cars you going to run into on the street....just gotta work on getting that power to the ground A good set of upper/lower control arms, with a good set of tires, gears, and a good shifter will make a world of difference!

[Shelby-Love]

Thanks guys for taking the time to give me such detailed feedback. Let me answer some your questions first. The gears I currently have are 3.55's, Shelby took out the 4.10's as part of the Shelby upgrade. That said, Shelby doesn't do anything to the motor itself, it's basically just sent from Ford over to Las Vegas where other Ford racing parts are put on like upgraded suspension (torch asked about this, but maybe this is not really good enough), it's lowered, dampers, springs, etc...I It has what Kris has said is a nice set of headers, but I'm not sure if they are shelby upgrades, stock or what. I have 18" wheels w/Nitto 555 R2's all around, but I am thinking I might want something larger, but especially wider. I guess the reason that I want more power/acceleration is just that I've gotten used to the power that is there and just feel hungry for more (greed is the only explanation). That said, I'm a newb, so if there are better alternatives than the ones that I mentioned (I pretty much ask Kris what I can do to get more out of it and those were his suggestions), then feel free offer advice. I don't plan on racing it competitively, but I may go to the track just to learn how to make better starts and vehicle control from those that are willing to share their knowledge. If you need any additional info, just let me know...

[Blackjack]

Gears defiantely!!!! I guy I work with has an 08 Bullitt, and it came with factory 3.73's. Where as the standard GT car's come with a 3.31 or a 3.55, and his car felt a lot more responsive. That is until he put a set of 20's on it. Lol! I'd go with the 4.10's, just my 2 cents.

[Shelby-Love]

Thanks, I also just wanted to make it clear that it is not a question of gears vs engine upgrade, I plan on getting different gears no matter what. I just need to know what gear ratio you guys think will be best for my car now and in the future if and when I add more power. Right now, I'm definitely leaning toward the 4.10's. That said, I am still looking at the best way to allow my KB supercharger to breathe. Also, that last post made me think, does wheel/tire diameter make a difference in terms of, well, anything (acceleration, etc...)? I know I wouldn't mind some 20" wheels, just wondering what impact that has on performance. Someone let me know how that works if you know...

[Blackjack]

Oh absolutely! Yeah, his Bullitt had a factory 18" wheel on it, and 3.73's. Now that he's got the 20" wheels, he's debating on 4.10 or probably even a 4.30's.

Here's a link you might check out, just remember it's the heighth of the tire, not the wheel that matters.

http://www.richmondgear.com/101032.html

[stumbaugh]

I would go MMR all the way. They have the fastest 3 valve car right now. A stroker 950 short block with ported heads and supercharger cams will make that car haul. 4.10s all the way. Up the boost to atleast 15psi. Maybe even 18 or so. You would be over 600rwhp.

[adam2kgt]

Glad somebody agreed with my rough estimate on power potential. If you have the money, please build it! You'd probably have one of the most powerful cars out of all of us.

[Shelby-Love]

One last question (or two)..

1.) Would it be best to go with something like 20" in the rear and something like 18" in the front or go big all around? Also, what is the minimum wheel width I should consider in order to get great traction?

2.) It seems to me that there might be a logical "roadmap" if you will, to building the beast you desire. I do realize that a lot is opinion, but are any of you aware of any document that outlines a progressive list of upgrades, kind of a checklist of upgrades that would allow you to slowly work your way up to having everything you want without missing a critical dependent upgrade due to some other mod you made? I'm guessing this might be something that would have to be hashed out by someone very smart that knows what they are doing. In other words, not me, I just get in and drive. I can change my own oil and brakes, but beyond that, too scared to mess with anything else by myself.

[screaming_pc]

4.10 imo are too steep for forced induction. Get a set of 3.73. It wont be much of a difference, but you will notice it.

[stumbaugh]

Well it's not all about how wide of a tire u have. It needs some sidewall so the tire can crinkle. 20s in the back and 18s up front would look good. I would atleast get a 10" wide wheel.

[Blackout_03]

1. 20's look amazing on the S197s...but you are limited in the type of tires you can run....Nitto makes a 555R for them but that's is so far. Size wise 20x9 Front 20x10 Rear Please don't stagger the wheel size..18's or 20's...pick one!

2. 4.10s are going to give the butt-dyno the best bang for the buck...but you will blow through 1st an 2nd in no time...I have 4.10s and with the spray its crazy. Its hit the gas for a sec...shift....hit the gass for 2 sec's...shift.....if your not a good shifter or have slow feet i would look at 3.73-3.90 gears. I think with the instant TQ of the twin screw 3.90's would be perfect...you wont really notice a difference with a 3.73 over the 3.55's

3. I would get a set of good upper and lower rear control arms...the S197 cars have horriable wheel hop...almost as bad as the 03-04 cobra IRS. You have a good tires wich helps a ton. Steeda, BMR, Maximun Motorsports all make great ones...just find the ones you like....we can install them in a few hours!

4. theres not really a check list that goes in what order to build your car....its all subjective to what you personal taste is...Im more of a sleeper kinda guy....only aperance things I have done to my car is a set of Deep Dish rear wheels and lowering springs. Just remember that 600+hp is going to break parts....trannies, rear ends, cluthcs....so you need to be aware of that when planning a build....what good is a dyno queen that makes 700hp....but every time you take it out you break something....my car isn't the fastest here....but i can drive in cross country.....run it to 100% of its ability and drive it back!

[hammerhead2]

There has already been a lot of good advice given but I will add my 2 cents as well. On the gear question I would make your choice after you decide which wheel size. If your going with 20" wheels ( which I would on that body style ) there is no question I would do 4.10's. Even with the Twin Screw. Yes you will have to shift quicker but you got to learn some day. There are a lot of good shops out there but if it were my money I would go with the MMR short block. I have yet to hear any thing bad about them from anyone. That KB 2.6 can make plenty of power with the boost turned up and you will need forged internals eventually. As far as heads and cams those are great things as well and will make good gains in power. They will hurt the streetablity a little though but that can be subjective. If you don't have headers get them. Those cars make good gains with Long Tubes. This could cause a drop in boost as well though so you may end up having to go to a smaller pulley when you do this. There are guys running up to 12psi with a meth kit on the stock bottom end making over 500whp and they are living. But lets face it, any time you start making big power and driving it hard your going to break stuff at some point. It's just part of the game. You just put it back together bigger and better.

[Shelby-Love]

I want to thank each of you for taking the time to explain these dynamics in detail for me. This is exactly the type of feedback I was hoping to receive. For a quick update, I purchased the 4.10's and I'm told it should be ready tomorrow. I like the idea of upgrading the control arms to reduce the hop because I have noticed that is causing the majority of my "good" starts. (Not sure if that was one of the "Shelby" upgrades or not springs, dampers, sway bars, etc.. is all I can remember). I heard someone say that they might be something that "I" or "we" could install? Do you mean that it's not very difficult or you have a shop and actually know what you're doing? I have a 2 car garage and some basic tools, but am building up at least the minimum items to work on and maintain the vehicle. BTW, some of you guys missed out on some good grub a couple weekends ago. Just to make you jealous, we had bacon-wrapped, jalapeno, jumbo shrimp kabobs, hamburgers, beer brats w/onions, chips and cold drinks and beer. I'll try and host again in hopes for a better turnout, but I understand everyone is very busy.

One last question? Does anyone know the URL to this MMR site? I've done some basic searching, but I'm not finding what I think you guys are talking about. As always, your help is invaluable to someone like me who just loves to learn.

[Blackout_03]

You will love the gears...just make sure you re calibrate your tuner or your speedo will be off. I ahve a shop at my house....nothing super fancy 30x30. i have done all the work on my car myself minus the gear install....and after watching it be done...i have no doubts i could do it.

i dont mind helping people mod there cars but im just as happy to let them pay somebody else to do it. Wanted to make it out to the cook out...but already had plans for a friends B-day party the same day....hope to make it next time!

[hammerhead2]

Food sounds awesome! Wish I could have made it out. Hopefully another time.

[Blackjack]

Wish I could've been there as well. A friend here has a 08 Bullitt, and he installed the control arms, springs, and new pan hard bar on his car his self. He only has a one car garage with standard tools. Hahaha!

[adam2kgt]

MMR's URL is:
http://www.modularmustangracing.com

They may not have everything on their website, but you could definitely call and talk to somebody. My dad is going through the basic mods on a 07 GT right now, and he loves the extra power. We are dealing with Brenspeed out of northern Indiana, closest shop to my dad. They seem to be great, so far. Another shop that seems to be popular and is closer is Brooksspeed. They are in Memphis, I think.

[Shelby-Love]

Thanks guys, I got in touch with MMR out of Florida and they were very helpful and responsive. They had a detailed quote/estimate to me within a day or so. Talked to the wife about a potential stroked, short-block and think I have her convinced, but am going to have to wait a few months. FYI, I bought some 20" Carroll Shelby CS69 Chrome wheels that are sitting at the tire shop waiting for my tires to come in. I went with the Nitto Invo's for my set of show wheels/tires and since I already have 2 brand new 18" Nitto 555 RII Extreme's sitting in my garage, I'm just going to buy 2 more and keep those for more serious driving events. I'll post some pics once I get the new wheels and tires on, they should look pretty sweet.

[ArkansasMystic]

Going to look amazing, and gonna perform great after the mods!!!

[Blackjack]

Sweet!!! It's going to look awesome!

[oxman]

yesir,,can't wait to see the new additions! 8-)

[hammerhead2]

Man that is awesome. Can't wait to see it finished.

[stumbaugh]

It should run real good. Just spray the hell out of.