hey,
I can get a set of M/T E.T. streets 28x12.5x15, and I was wondering if they will help me or hurt me in the 1/8th mile going from a 26" tall M/T street?

Here is what im running...

72' 350 block
.020 over-honed for moly rings
Zero decked W/ .028" head gasket(nice tight quench)
11-1 static 8.3-1 dynamic
Scat 9000 3.75" crank
G.M. 5.7" rods
K/B sil-o-lite F/T single vlave relief
Dart iron eagle-180 cc runners, 64 cc chambers 2.02/1.60...bowl port, radius valve job, valve profile.
Howards custom ground solid roller- 260/264 @.050, .620/.630 lift, 109 L/C W/ 6* adv.(int. 103*) small base circle, 2 piece core
crane solid roller lifters
Comp pro series pushrods
1.5-1 roller rockers
Victor Jr.
750 double pumper(milled choke horn, usual tricks)
MSD 6A HEI system
1 5/8" headers, 2.5" exh. Flowmaster 40 series
clutch fan(for now)


Th350
TCI Reverse pattern valve body
TCI Streetfighter 10" converter

12 bolt with G.M. 3 series posi carrier
Strange posi gears
Mosier axles
Richmond 4.10 r/p
ssm Lowers- boxed uppers with poly bushings
KYB gas shocks
M/T e.t. streets 26x10.5x15


Best 60' with the 26" tire= 1.701 spinning
Best et. W/ 1.74 60'= 7.67 @ 89 mph

Is going to a 28" tire going to be too tall and hurt performance?

also, I plan on trying some 4.56 gears in the future. Within the next 6 months.

please let me know what yall think.
thanks mark

Hello there. Try going to prestage.com, they have a calculater that will tell you what the effects would be. It will slow you down a little bit most likely. It would have the same effect as going from 4.10 gears to 3.73 gears. Tire size will change the final drive ratio and acceleration. Thanks, Erik

In the 1/8, I think it will hurt you. Your engine likes to rpm and bigger tires will go in the opposite direction. If you run only 1/8 mile, 5.13 or more might be better gears, then you could run the taller tires. Of course, if you drive on the street, even 4.56 will not be fun on the highway.

What is the trans gear ratio I use with a 400 turbo

so, yall think they are too tall huh?
ok, I noticed alot of people on here running 28".
thanks, mark

I'm going to buck convention here and say the 28"s will help. Just another suggestion - you need to get a looser converter that's more appropriate for your combo... or add a nice 250 shot of squeeze.

In all fairness though, there's a lot of other info left out of your profile. 26" tall slicks can be made to work - guys running real street class here are running mid 5's through the 1/8 mile on them now. Make sure you have all the basics covered - weight transfer, initial tire plant, etc. or else the taller tire will just spin as well.

Good luck, graemlins/beers.gif

jC.

hmmmmm.
any other opinions?

thanks, mark

i made this very swap. 26" nittos to 28" M/T ets. i have a th350 with 4.11s. the car does hook a little better on the street with the larger tires but there is a noticable difference in how the car pulls from the top of second and into 3rd. the larger tires really took some of the performance away at higher speeds. no track times yet. will test both sets soon. DAVE

Im going to wait and save up for some 26x11.5x15 and go with a 4.56 gear.
this should do pretty good.
thanks, mark

Mark,

In my opinion the best thing to do on any car that will see drag strip use is to put on as big of a tire as you can fit and then gear it to match your combo.

jason,
I know your running 28's and a 4.56.
what do you go through the traps at on the 1/8th?

see, if I only raced it, I would go with something in the 5.xx range and a 28" tire, but I still drive it on the street. not everyday, but enough that 5.xx is too much.

I can get a set of Richmond 4.56 for a really good deal, and save up for some more 26's. That would get me closer to the best combo for the best price, and on the street use my 27" tires.

Talk to yall later, mark

5400-5500 RPM in the 1/8th.

oh, ok.
I have not made enough passes to remember to look and see what im going through the traps at.
Im thinking its around 4500-4600.

I think it needs to be around 5500-6000.
I bet this TCI street fighter(10", off the shelf) isnt helping naything either.

talk to ya later, mark