JFM-jr

iTrader: (23)

Figured out my car has been shifting into 4th gear (O.D.) at about the 900-1000ft mark. Lugging 4th thru a good portion of the back half. Currently running heads/cam stock shorty so 7K rpm limiter. 26X10.5X15 Hoosier QT's 4.11 Moser Yank PT4400. When I manually put the shifter in drive I hit the 7K rpm ceiling at what I would guess is the 1100 ft (I could be off) but I was well short. In O.D. I cross at about 6500. Log shows from 96mph to 120 mph only covers 150rpm spread from 6400 to 6550. This spread is where the 3rd and 4th gears cover. Any others running this combo with some info?I got the 1st half covered she sure still leaves like all hell


Gotta figure wich direction to go here

camscam02

iTrader: (21)

put 28 inch tires on it and it will solve your problem

JFM-jr

iTrader: (23)

Wish it were that simple 28" tire will only add 6mph

camscam02

iTrader: (21)

i trap 130 and its right at the rev limter.... 6900 rev limter.... and many people can get 135 or so out of them... i trap 123 on motor and am at around 6400-6500 going thruogh the lights!

camscam02

iTrader: (21)

i run 4400stall and 4.10 gears as well with a 28inch tire

bad2000z

iTrader: (4)

Crap! I'm probably gonna run out of gear too. I just switched to 4.11's and I run a 26" tire. I might have to switch to 28's too.

Jantzer98SS

iTrader: (54)

Your probably just running out of gear. You want to stay out of OD though.

I ran the exact same setup... TP4400, 4.10s, heads/cam, stock A4. I would pull the traps at 123-125 and just be on the rev limiter at 7000 . Same exact tires as well. I would go with the 27" QTP's to maximize that combo. 28's will give you too much MPH.

JL ws-6

iTrader: (50)

28 inch tire will get you enough room, you have to remember that they will grow about an inch at speed so calculate off a 29 inch diameter tire.

fwiw with 4.10's and a 28 inch tire, 9% converter slippage I went 139.2 @ 7150rpm. More rpm then you want to turn I know, but you've not gonna see 139 mph traps either. Could the tranny possibly be slipping at all, because that will cause ya to need to use all 4 gears too.. and with a 4ljunkie tranny, I always consider them suspect in any car that's got power/runs good.

Matt D

iTrader: (49)

I think your trans is slipping. Is it built or stock? What are your shift points? With a PT4400 and 3.73 gears, I was seeing 12% efficiency at a 3100 raceweight. With a 4.10, it should be around 8-9%, and you shouldn't be hitting OD with a 26" tire unless you are shifting at 6200 or so.

bad2000z

iTrader: (4)

Can someone figure out what RPM I'll be going through the traps at? My traps range from 120-122, 26" tire, 4.11's. Thanks!

Sorry for the hijack.

Pro Stock John

iTrader: (34)

Yeah I'd go 27's before I went 28's.

NHRAFORMULA00

iTrader: (2)

I would not go 27 inch,it not gonna be enough. I run this same exact combo 125-127 mph with 28" ET drags 4.10 gear and im at 6900-7000 in the traps in 3rd.My converter slippage plays out to be around 12-13 percent,pt 4400.Sounds a little loose to me ,but i could care less.If you tighten it up it will never produce the numbers on the bottom end where its making the the best reduction in et.These tires will grow a lot,i have seen mine on the dyno grow almost 2". 1 " on each side.And my trans is NOT slipping,101 in the 1/8, 127 in the 1/4.26 mph gain on the last 660.

Jantzer98SS

iTrader: (54)

I would go 27's and lock the verter manually. I could hit 125 with 26's with my setup and just be hitting the rev limiter. The 27's will go 130. If you don't lock the verter, you might need 28's.

Do you lock the verter?

JFM-jr

iTrader: (23)

Well I am in sort of a good position here. My ring and pinion are screaming and are getting replaced. I could go with a 3.90 tho this would fall just a little shorter than leaving the 4.10 on a 28. I am curious as to how a 28" tire will effect my numbers downstairs. Additional 2 lbs per tire to carry the entire 1320 as well. I do not lock the converter Yank advises agianst it. NHRA seems to have a very closely matched setup to me. I had been scratching myu head the last 2 track rentals wondering where my additional 2-3 mph was. O.D. ate it on me LOL. I too trap 101 at the 1/8 (6.68-6.70)and go 123. I've run nothing but Yank converters in this car this is my 3rd I went from a 3600 to a 4000 to this 4400 i'd never run anything other than a Yank. I am glad to see NHRA's setup confirms things for me.

JL ws-6

iTrader: (50)

I'd put another set of 4.10's in the car, go with a 28x105x15S et drag, the little bigger tire will make the car hook more consistant when the track isn't absolutely perfect, and when the track is good, add air pressure

WE TODD DID

iTrader: (2)

Get a converter built for the car rather than guessing on what you need.

JL ws-6

iTrader: (50)

Probably something to be said for that as well. Have Lenny @ Ultimate build ya one, probably knock another .2 off going to a 28 inch tire and one of his converters.

JFM-jr

iTrader: (23)

I think i'll stick with Yank i've had solid results from them since like 2000. In fact i'm still on the stock internals top 50 list many years later Yank converter then as well. This is NOT to say Ultimate does not build a quality product (tho i've never heard of them). when I get the gearing squared away (leaning towards the 28's) i'll burn off a 10.4X@127ish I know the car has it in it.

JL ws-6

iTrader: (50)

Ultimate Converter Concepts. Look them up. Local right in milford CT, ya can go take a tour of the shop and talk to Lenny in person if you want. They're really big in teh mustang world, built all the converters for the Eastside race cars, which have certainly had no problems going fast for some time now.

JFM-jr

iTrader: (23)

My car was tuned at Eastside back when Kevin (NOGO) was doing the magic. I was there about a year ago Kenny tuned a friends Z-28. The Eastside gang used to make trips to LI when we had our dragstrip here many years ago. They know my car and the fact it has been going fast for some time now as well. Eastside is some of the best in the bussiness!!!