[jdw_poncho]

I thought ATI did.

[RAIV-Z]

Originally Posted by jdw_poncho

I thought ATI did.

ATI only lists a 4.00 gear for the ford 9.50 rear.
What size tire and trans are you planning on running?

My current turbo400 trans has standard gears and I'm looking at 33" tires.

[Jim Yanoski]

Do yourself a favor and buy the 9.5" the first time! Lamb stocks and Tom's make 3.89 9.5 gears I don't know about anything higher. Also make sure the rear housing is clearanced for the 9.5 ring gear before you clean it all up after the fab work. 9.5 gears will not fit in a stock 9" opening..........Jim

[RAIV-Z]

Originally Posted by Jim Yanoski

Do yourself a favor and buy the 9.5" the first time! Lamb stocks and Tom's make 3.89 9.5 gears I don't know about anything higher. Also make sure the rear housing is clearanced for the 9.5 ring gear before you clean it all up after the fab work. 9.5 gears will not fit in a stock 9" opening..........Jim

Hi Jim,

I’m all for going with 9.5 gears, but I don't think 3.89’s would be the best choice.
Assuming the following, what would work best?
I can't do much about the weight, but the tires, trans and converter are all up for debate.

1600hp
3300lbs
Turbo400 Trans “Internal Gears TBD”
33 inch tires
< 7000RPM
~10% converter slippage?

Thanks,
Ed

[BruceWilkie]

10% seems to be a lousy convertor IMO

Manual trans... MPH= (TD x RPM) / (GR x 336)
Auto trans...... MPH= (TD x RPM) / (GR x 355) (decent convertor)


(33*7000) / (3.89 x 355)= 231000 / 1380.95 = 167.27 Only 1270 hp needed for that speed.

However...3300lbs and 1600 hp should go around 180 mph.

You need 3.55 gear to do 180 at 7000 rpm. OR turn about 7600 with a 3.89 gear.

[RAIV-Z]

Originally Posted by BruceWilkie

10% seems to be a lousy convertor IMO

Manual trans... MPH= (TD x RPM) / (GR x 336)
Auto trans...... MPH= (TD x RPM) / (GR x 355) (decent convertor)


(33*7000) / (3.89 x 355)= 231000 / 1380.95 = 167.27 Only 1270 hp needed for that speed.

However...3300lbs and 1600 hp should go around 180 mph.

You need 3.55 gear to do 180 at 7000 rpm. OR turn about 7600 with a 3.89 gear.

I haven’t had a converter built yet; the 10% was wishful worst cases as I’ve heard heavy cars with tall gears tend to experience a higher percentage of converter slippage.
With the current cam, topping out at 5800rpm “660hp” and 4500rpm “670tq”, is 7000rpm boosted a realistic rpm?
Which ratios are readily available for the ford 9.5”?

[Jim Yanoski]

Originally Posted by RAIV-Z

I haven’t had a converter built yet; the 10% was wishful worst cases as I’ve heard heavy cars with tall gears tend to experience a higher percentage of converter slippage.
With the current cam, topping out at 5800rpm “660hp” and 4500rpm “670tq”, is 7000rpm boosted a realistic rpm?
Which ratios are readily available for the ford 9.5”?

Richmond 4.11 4.29 4.57

There are many other things to factor in. You also have to factor in TIRE GROWTH! The rollout is more important than the advertised diameter. Why would you cap it as a 7000 RPM ?

[Tom Vaught]

Food for thought:

Langer turns his engine over 8000 rpm routinely.

I saw Bryan's (Goatracer's) Engine go to 8500 at least 26 times on Holbrook's dyno without any issue.

The Keen's used to run 9000 rpm (WITH BOOST).

If you take a NA Engine and add Boost, typically the cylinder pressures DO NOT DOUBLE. You add 15-20 psi of boost and the cylinder pressure goes up by maybe 7% to 10%. The extra power comes from the extra Mass Flow in the cylinder allowing a longer "push on the piston" every combustion event.

The Inertial Loads are higher (when the engine swaps direction at the top of the overlap stroke) as the rpm increases but we have a lot of guys now running 8000+ rpm without ripping the piston off of the rod.

If you have a quality engine build, (which you have from Uncle Tony) there should be no issues with rpm. Springs, is another story. Springs should be sized for rpm and boost level. A Lot of Boosted Engines out there with guys who could tell you about their springs (as well as the PAC Guys who are the experts).

JMO

Tom Vaught

[RAIV-Z]

Originally Posted by Tom Vaught

Food for thought:

Langer turns his engine over 8000 rpm routinely.

I saw Bryan's (Goatracer's) Engine go to 8500 at least 26 times on Holbrook's dyno without any issue.

The Keen's used to run 9000 rpm (WITH BOOST).

If you take a NA Engine and add Boost, typically the cylinder pressures DO NOT DOUBLE. You add 15-20 psi of boost and the cylinder pressure goes up by maybe 7% to 10%. The extra power comes from the extra Mass Flow in the cylinder allowing a longer "push on the piston" every combustion event.

The Inertial Loads are higher (when the engine swaps direction at the top of the overlap stroke) as the rpm increases but we have a lot of guys now running 8000+ rpm without ripping the piston off of the rod.

If you have a quality engine build, (which you have from Uncle Tony) there should be no issues with rpm. Springs, is another story. Springs should be sized for rpm and boost level. A Lot of Boosted Engines out there with guys who could tell you about their springs (as well as the PAC Guys who are the experts).

JMO

Tom Vaught

Hi Tom,

I'm looking to replace the springs with either Manley NexTek 221425P or PAC-1328. So 7500-8000rpm is not an issue with the current cam?

[Tom Vaught]

I would e-mail a copy of your cam card to Travis Quillen and see what he thinks as far as your proposed camshaft's capabilities are with boost.

Travis has probably tuned more Boosted Pontiac Engines than anyone.

Tom Vaught

[RAIV-Z]

Originally Posted by Tom Vaught

I would e-mail a copy of your cam card to Travis Quillen and see what he thinks as far as your proposed camshaft's capabilities are with boost.

Travis has probably tuned more Boosted Pontiac Engines than anyone.

Tom Vaught

I took your advice, Travis said the new cam is still a bit small but should be OK up to 7600rpm.

[Tom Vaught]

Yep, Travis is a good man.

Tom Vaught

[RAIV-Z]

Replacing the Powerbond "PB1056-SS" slip fit SFI damper with one which in my opinion is more suitable for the intended application.

[mysticmissle]

Eek powerbond on a 1500hp motor. Keep doing what you want ED. If its over built you'll never hurt it

[Tom Vaught]

Basic Powerbond Harmonic Balancer is kind of "out of character" on a 1500 hp engine, even a "STREET ENGINE".

Tom Vaught

[RAIV-Z]

Originally Posted by mysticmissle

Eek powerbond on a 1500hp motor. Keep doing what you want ED. If its over built you'll never hurt it

The design goal was 1600hp Pump Gas.

Rockers are next on the list...

[jdw_poncho]

Originally Posted by RAIV-Z

The design goal was 1600hp Pump Gas.

Rockers are next on the list...

Holy chit, are you serious? With the amount of material cut away what size pushrod did he put in that thing 1/2"?

[RAIV-Z]

Originally Posted by jdw_poncho

Holy chit, are you serious? With the amount of material cut away what size pushrod did he put in that thing 1/2"?

Unfortunately I am serious, even with that much material removed from the rockers quite a few of them have marks which indicate they are still making contact with the springs/retainers.

The pushrods are Manley 25374-16 9.750 length, 3/8 diameter, .120 wall.

Take another look at the original balancer picture above. Those metal shavings were packed in behind the balancer bolt.

[jdw_poncho]

I thought those looked like metal shaving but was waiting for someone else to say it. LOL - Good luck, at least your finding the problems now and not on the track.

[cgeise]

Originally Posted by RAIV-Z

Unfortunately I am serious, even with that much material removed from the rockers quite a few of them have marks which indicate they are still making contact with the springs/retainers.

The pushrods are Manley 25374-16 9.750 length, 3/8 diameter, .120 wall.

Take another look at the original balancer picture above. Those metal shavings were packed in behind the balancer bolt.

Take a look at the picture -- If those are Manley springs the end with the champher should be up - -unlike yours - that would contribute to your spring retainer issue - although prob will not fix it --and Id say goodby to those rockers --