Please help

[mk028]

I have asked these questions to a bunch of people and either no one knows the answer or no one gives the same answer.

1. I own a 2004 cobra, will 10.5 rims fit on the rears without having to do any modifications? If the answer is yes, can I put "true" 315's on without having to do any modifications? What I mean by "true" is that I know that Nitto 315's are smaller then any of the other manufacters 315's. So would I be able to fit a pair of BFG 315's on the rears without modifying the wheelwells, supspension, ect.

2. I have exhaust with catback, CCI, upper and lower pulleys, SCT chip, stieg. ported eaton, upgraded throttle body and spark plugs, and am running 101 octane fuel (torco). The place that did the work and tune for me have a mustang dyno and dyno'ed by car at 420rwhp. They told me that mustang dyno's typically rate the rwhp at 20-25% lower than dyno-jet dyno's do. They told me on a dyno-jet I would be at around 525rwhp. Is this true that mustang dyno's are 20-25% lower??

3. I read the posts on the question about Whipple vrs Kenne Bell. Now that the new models are out does anyone have any different opinions? Which one is more reliable and less likely to break or have mechanical problems. It seems like either one will pretty much give you the same rwhp. Any info about this subject would be greatly appreciated. I would like to know anything about either supercharger. Thank you to all that took the time to read the novel I wrote above, my appologies for the length.

[BurnTire]

I have asked these questions to a bunch of people and either no one knows the answer or no one gives the same answer.

1. I own a 2004 cobra, will 10.5 rims fit on the rears without having to do any modifications? If the answer is yes, can I put "true" 315's on without having to do any modifications? What I mean by "true" is that I know that Nitto 315's are smaller then any of the other manufacters 315's. So would I be able to fit a pair of BFG 315's on the rears without modifying the wheelwells, supspension, ect.

2. I have exhaust with catback, CCI, upper and lower pulleys, SCT chip, stieg. ported eaton, upgraded throttle body and spark plugs, and am running 101 octane fuel (torco). The place that did the work and tune for me have a mustang dyno and dyno'ed by car at 420rwhp. They told me that mustang dyno's typically rate the rwhp at 20-25% lower than dyno-jet dyno's do. They told me on a dyno-jet I would be at around 525rwhp. Is this true that mustang dyno's are 20-25% lower??

3. I read the posts on the question about Whipple vrs Kenne Bell. Now that the new models are out does anyone have any different opinions? Which one is more reliable and less likely to break or have mechanical problems. It seems like either one will pretty much give you the same rwhp. Any info about this subject would be greatly appreciated. I would like to know anything about either supercharger. Thank you to all that took the time to read the novel I wrote above, my appologies for the length.

1. It have read that you may need some spacers to get the 10.5's to fit correctly without hitting the IRS bolts.
I personally would just stay with the stock cobra wheels. I know people have put the 315 nittos on the stock rims. I run the 275 nittos on the street on stock wheels.

If you are going to hit the track on IRS I do not recommend drag radials.
The will still wheel hop. Go with M/T ET Streets on a set of diamond racing wheels.

2. Mustang dyno does create lower numbers. I am not sure on the %.

3. Whipple or KB are both reliable and do the same thing. I prefer the whipple because I feel it looks better and is quieter. It is more of a personal preference.

[speedracer]

I have asked these questions to a bunch of people and either no one knows the answer or no one gives the same answer.

1. I own a 2004 cobra, will 10.5 rims fit on the rears without having to do any modifications? If the answer is yes, can I put "true" 315's on without having to do any modifications? What I mean by "true" is that I know that Nitto 315's are smaller then any of the other manufacters 315's. So would I be able to fit a pair of BFG 315's on the rears without modifying the wheelwells, supspension, ect.


I have FR500's on my car (10.5's in back) with Nitto 315's and when you first put th rims on it looks like they will rub the IRS bolt but as you lower the car back down the IRS bolt goes down with the body into a place where ther is more clearance, I plan on putting Hoosier 315's on this spring and I'm not worried about them rubbing. Lethal Performance sells a IRS bolt that's for more clearance too. There is plenty of room in the wheel wells too.

[BLK03SVT]

I have asked these questions to a bunch of people and either no one knows the answer or no one gives the same answer.

Disclaimer: I'm no expert but...

1. I own a 2004 cobra, will 10.5 rims fit on the rears without having to do any modifications? If the answer is yes, can I put "true" 315's on without having to do any modifications? What I mean by "true" is that I know that Nitto 315's are smaller then any of the other manufacters 315's. So would I be able to fit a pair of BFG 315's on the rears without modifying the wheelwells, supspension, ect.

2. I have exhaust with catback, CCI, upper and lower pulleys, SCT chip, stieg. ported eaton, upgraded throttle body and spark plugs, and am running 101 octane fuel (torco). The place that did the work and tune for me have a mustang dyno and dyno'ed by car at 420rwhp. They told me jet dyno's do. They told me on a dyno-jet I would be at around 525rwhp. Is this true that mustang dyno's are 20-25% lower??

3. I read the posts on the question about Whipple vrs Kenne Bell. Now that mustang dyno's typically rate the rwhp at 20-25% lower than dyno-that the new models are out does anyone have any different opinions? Which one is more reliable and less likely to break or have mechanical problems. It seems like either one will pretty much give you the same rwhp. Any info about this subject would be greatly appreciated. I would like to know anything about either supercharger. Thank you to all that took the time to read the novel I wrote above, my appologies for the length.

1. I know the 315 BFG's rub, but they are a wider tire. My buddy runs a 315 BFG on a 10.5 rim and uses a 3/8" spacer. There are a lot of guys running 10.5's with nittos and no spacer and I think the IRS bolt needs to be shaved.

Check out this post for some info on the 315's on a stock rim: http://www.svtperformance.com/forums/showthread.php?t=360674 It doesn't look too bad and doesn't buldge too much.

I can tell you that you don't want to go any smaller than a 315 in a Nitto. I've got the 305's and they really don't look as wide as they should. They do hook much better than the stock F1's though.

2. I've done some research on this and it seems to be closer to 10-15%. But there are people that claim as low as 6% and as high as 18%. Here's a useful thread:
http://www.ls1tech.com/forums/showthread.php?t=459250

3. I agree with Jeff- I'd go Whipple, but both seem to be great blowers.

[BLK03SVT]

I have FR500's on my car (10.5's in back) with Nitto 315's and when you first put th rims on it looks like they will rub the IRS bolt but as you lower the car back down the IRS bolt goes down with the body into a place where ther is more clearance, I plan on putting Hoosier 315's on this spring and I'm not worried about them rubbing. Lethal Performance sells a IRS bolt that's for more clearance too. There is plenty of room in the wheel wells too.

Do you have stock springs?

[Venomous Bite]

I had 315 bfg's on the stock wheels with no spacers on IRS but I also own a yellow car so :pinkthumb:.

[speedracer]

Do you have stock springs?
Yes.

[50 BMG]

Shaggy and I both had BFG 315 DR's on stock wheels with stock IRS bolts.

Never had an issue.

[Indy]

The bolts normally only touch the tire when the cars off the ground. Its not an issue under normal driving most of the time.

[NOEQUAL]

I have have 10.5 wheels and 315 nittos with a spacer and have no probs what so ever. I also have no probs with wheel hop at the track, at speed world i went 12.1@116 with a 1.9 60 no prob.