roots/centrifugal style blowers on a 4.6 SOHC vs. heads/cam/intak mani.

Discussion in 'SN95 4.6L Mustang Tech' started by Johns96SS, Dec 4, 2003.

  1. J98GT

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    He said in his first post he doesn't want gobs of power and he has a 2K budget.

    I think the KB is a bit more than he is looking for. Hence my suggestion of a used roots off E-bay or the classifieds.
     
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  2. kirkyg

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    2k budget...hahahaha...i think boltons are about all you can do with 2k...and not even really that. You better get a NOS kit if you want 350 rwhp.

    kirkyg
     
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  3. JLstang351

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    I have a 98 gt. here come tax time I hope to have 300rwhp with only spending around 2k-2.5k. I am going to be buying a set of pi heads have them ported along w/ valve job. Long-tube headers and a x pipe for the Lt's. If that isnt enough i will be buyin a set of cams. But hopefully w/ the porting and lt's i will be near 300hp. Also i plan on doing the swap myself, except the porting to help in the financial department
     
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  4. Sam98

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    You reiterated my point...a 97 motor with a roots blower IS NOT GOING TO PUT DOWN 350 RWHP, which was his target. :stick:
     
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  5. J98GT

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    That is true. But you won't get 350 rwhp from ANY blower with those stock heads/cams/intake.

    My point is the torque curve more than makes up for it. The car was FAST and a blast to drive with that combo.

    I'd take 300 roots blown hp over 300 centrifugal blown hp any day. So many people are quick to bash roots blowers without ever owning/driving them. I've owned BOTH, and at the power level that $2K will buy him (~300rwhp) Roots is DEFINATELY the way to go. If hes willing to spend 7-8K for a set-up like mine, then yes, I'd definately say go with a Vortech or KB.
     
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  6. Sam98

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    So would I, but that isn't what we are talking about. It is more like 280 RWHP from roots, compared to 320 RWHP with a centrifugal setup. And by the way, even with my centrifugal and stock gearing, I can't get enough traction for 1st gear to be useful and I have to watch it in second. More torque down low wouldn't be a good thing for me. :D
     
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  7. kirkyg

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    sounds like your not riding the clutch enough

    i think 320-350 rwhp can be done on a non-pi head stang it just will take some risky boost 10psi or so with a KB or centrifugal. Roots wont get anywhere close.

    kirkyg
     
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  8. J98GT

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    Don't fear the torque. That low end torque is what will let me clean the floor with you in a race. I've done it on the track. Not only did I beat a Vortech'd 94-95, but I ran him down from behind and passed him before the finish line.

    280rwhp on a MUSTANG DYNO with a super rich tune (10.2 - 1). 03 Cobra's put out 320-325 on this dyno. The car would have put down comfortably over 300rwhp on a Dynojet.

    Sam, what is your combo? Any dyno numbers or track times?

    As I've said before, I have extensive seat time with BOTH types. On a non PI headed car with, there is no comparison. Unless you've owned both, I don't see how you can agrue.
     
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  9. Sam98

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    You're trying to tell me that a 96-98 GT, with stock heads can make 300 RWHP with a roots blower... :rlaugh: I don't think so. I don't care what GT you are talking about, if you can get 300 out of it with a roots, you can get 350-375 on the same car, at the same boost level with a centrifugal. Roots blowers are not efficient - not on a Cobra, not on a 98 GT, and not on a toyota corolla for that matter. The roots will make more power up to around 3500 RPM, but over 4000 RPM there is no comparison. Twin screw is a different story, but that is still new and I have yet to see a 96-98 with stock heads and a Kenne Bell. :nonono:

    And for the record I'm not afraid of the torque, but since I already can't get traction with the accelerator down half way in first I don't need it. I'd be delighted to have it, provided it didn't degrade the top end. Most of the roots blowers out there would be hard pressed to get 250 RWHP out of an otherwise stock 96-98 GT. Spend an extra $2000-$3000 and maybe they will, but not with just the blower kit.

    The first time I put my car on the dyno it was making 254 RWHP and 322 RWTQ with nothing but the Novi 2000 @ 8 psi. With my exhaust it jumped to 284 RWHP and 312 RWTQ. I haven't checked it since I replaced the cams but there was a significant SOTP improvement. BTW...the elevation here is 1 mile above sea level and the barometric pressure is typically 25 in Hg. which does have a dramatic impact. I got on the dyno right after a Corvette with a 383, high performance cam, torker intake and headers that was only putting down 212 RWHP. :D
     
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  10. J98GT

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    Are you familiar with the difference between a Mustang Dyno and Dynojet?

    Mustang Dynos read ~10% lower than dynojets due to the way they load the car. FYI, My neighbors 00GT with exhaust, pullies and an NX 75 shot ran 282rwhp on the same dyno in similar conditions.

    I can e-mail you these dyno sheets if you want.
     
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  11. 46gtsblown

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    I am going to have to agree with J98GT. For 2 grand and a stock 97 motor the best way to go for reliable daily driven car the SVO/Roush blower is the best way to go. Just by installing PI cams and using the 3.3" pulley he will be at the 300 hp mark and a butt load of low end TQ. The TQ will give him the grunt out of the hole without having to rev the stock motor to the moon to make power. You will not see the 330-350 you are wanting but the combo is bullet proof fuel milage dosen't change and you won't even know it is there until you stand on the throttle.

    Dwayne
     
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  12. JLstang351

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    what kind of power can you get w/ the svo blower after you put on ported pi heads and long tubes. Does 375rwhp sound to high? deffinately 350 right :shrug:
     
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  13. LI98GTStang

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    I don't believe you can put on the SVO blower with the PI heads as it comes with the intake - made for the NPI heads.
     
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  14. JLstang351

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    In the 03 ford racing catalog it has A kit for pi heads on non pi head car! It also says there developing a kit for 99+cars! I think it could hit 350+to the wheels w/ the blower!
     
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  15. RedGTvert

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    Just post them as an attachment.

    Then we can all view them.
     
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  16. J98GT

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    I'm not going to argue anymore, but here's my dyno sheet . . .
     

    Attached Files:

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  17. LI98GTStang

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    Sorry, haven't had an updated catalog in a while, but that's good news for the 99+ cars to give more choices.
     
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  18. D97GT

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    Here is a link to my recent SVO SC dyno on my mostly stock 97 GT. http://www.corral.net/forums/showthread.php?s=&threadid=391737&highlight=d97gt
    My only major mods besides the SVO are a bassani catted X and stock PI cams. Everything else is stock, Stock heads, stock exh manifolds, stock catback, stock maf and throttle body! I'm also only running a 3.55" pulley (approx 6.5psi of boost across the RPM band, 8 PSI at 6K). With a 3.4" I'm pretty sure I'd see another 8-12 rwhp. With good cams the 96-98 + SVO SC combo will put out well over 300 rwhp. I'm fairly positive with a set of the comp cams longer duration cams I'd see around 320 rwhp and thats without a pulley change. The Vortech on a stock 96-98 will not get you there due to the poor flowing intake. I've seen several people with stock motored 96-98's cranking 13 psi of boost with an s-trim only making 310-315 rwhp. That was even running them very lean with an 8:1 fmu on most and one guy was even running a 6:1 FMU. Needless to say it wasn't long before his motor cratered.
     
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  19. BLK_ROUSH

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    Check the sig. :p

    Either you really didn't do any research or you weren't around in 98 when the SVO blower power question came up. 300rwhp is quite possible on an otherwise stock 96-98 SOHC at 8-10#.

    I don't think anyone is arguing the efficiency of the roots set-up. The counter point is direct -> 300+ rwhp is possible out of roots blower on a stock set-up.
    Been doing it for 5+ years now.
     
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  20. White360RFnSwee

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    alrighty..

    do a headswap, cams, port and polish those heads before you put em on.

    Do full exhaust ( longtubes, no cats, catback ) a new Mass Air, and wait a bit for the Fox Lake intake to come out..

    You'll see over 300 rwhp guaranteed. A guy iwho runs a local car club ( he is on here too.. Kurgan ) made a ton of power with new cams... and he has the regular bolt ons..

    -Ryan
     
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