6 to 4 bolt

[Jon_0_3]

hey i was just wondering how i can fing out if my car has a 6 to 4 bolt combo or when i go to get a new car how i can cheak that one?

 

[BlandAnalogy]

look at the flywheel...

 

[90talon_Casum]

only an early 92 can have that combo. 6 bolt motors are found in first gens up to the first half of 92, then they started putting in the 7 bolt motors. The 4 bolt rear is only found in the 92's any other first gen has a 3 bolt... I have to go so I can't further explain this, sorry. hope that helped anyway

 

[Game Over]

only an early 92 can have that combo. 6 bolt motors are found in first gens up to the first half of 92, then they started putting in the 7 bolt motors. The 4 bolt rear is only found in the 92's any other first gen has a 3 bolt... I have to go so I can't further explain this, sorry. hope that helped anyway

You did a good job...

Just check the build date on the car, if it is between Jan '92 and May '92 I believe it will have a 6/4 combo.

 

[I-luv-em-all]

look at the flywheel...

Terrible reply, Im sure when he goes to look at another car he is not going to pull the motor out, take off the tranny to count the bolts on the flywheel .

Here is a real answer. 90-91 all have 3 bolt rear ends. 92-99 all have 4 bolt rear ends.

90-91 all have 6 bolts, some early 92's have 6 bolts, their is many ways to check that if it is before april/may it will most likely a 6 bolt. another way to check if it is a 6 bolt is to go under the car and look/feel the oil pan it is is flat/smooth it is a 6, if it caves in like a v then it is a 7 bolt. go to www.vfaq.com to look at pics of that.

 

[Jon_0_3]

thanks for the help so if i am getting a 93 tsi awd its gonna have a 7bolt to 4bolt it im right?

 

[HighPsi92GST]

unless someone swapped parts around, a 93 will have the 7/4 combo

 

[honduraneclipse]

heres one way you guys might not know , how to tell the difference between a 6 bolt and 7 bolt.. if you take a look at the exhaust manifolds stud fastener lugs the 7 bolt ones are almost twice the size of the 6 bolts.

 

[HighPsi92GST]

unless someone replaced the nuts/studs at some point....

 

[I-luv-em-all]

Looking at the oil pan is the most bullet proof way.

 

[Jon_0_3]

what is the different in performance between the 7 to 4 bolt and the 6 to 4 bolt

 

[tstkl]

nothing

the difference is that the 6 bolt can handle more power than the 7 bolt and the 2g 7bolts had higher compression and crappier almost everything else..(throttle body, intake manifold, head, bov, TURBO, and the list goes on...) but produced more hp cuz of a 1psi increase in boost and a .7 CR increase.... 1gs were 9-10 psi, while the 2gs were 10-11psi

 

[honduraneclipse]

what makes you say the 6 bolt can handle more horsepower. the 7bolt has the exact same capabilities to handle horsepower. You can say one thing though the bearings in the 7 bolt block/crank wear out radically quicker causing the chances of crankwalk. I swapped out my 7 bolt with 50.000 miles which walked for a 6 bolt with 180,000 miles on it and it runs like champ. except for the misfiring i need DSM link
by the way if you want to tell the difference just look at the oil pan the 7 bolt pan is different..theres a write up on it somewhere.. I'm just to lazy to look for it.

 

[Jon_0_3]

the car i am looking at is a 91 tsi awd what is the difference in the tranys on the cars?

 

[Burnett03]

nothing

the difference is that the 6 bolt can handle more power than the 7 bolt and the 2g 7bolts had higher compression and crappier almost everything else..(throttle body, intake manifold, head, bov, TURBO, and the list goes on...) but produced more hp cuz of a 1psi increase in boost and a .7 CR increase.... 1gs were 9-10 psi, while the 2gs were 10-11psi

early 7 bolts had 14bs and 1g BOV's. So i dont see how thats crappier?

 

[marcmsj]

You did a good job...

Just check the build date on the car, if it is between Jan '92 and May '92 I believe it will have a 6/4 combo.

my build date was 10/91 and i have the 6/4 combo. i guess it's if you have a 1gb built before around 5/92, then it should have a 6/4 combo.

 

[Syndicate13]

All 7 bolt motors have thinner rods, regardless of year. The 7 bolt is engineered to be a better motor but for whatever reason (crappy tolerances, crappy assembly, etc) isn't. Here is a theory from a local guru.

I am 100% sure I have discovered why 7 bolts are more likely to crank walk than a 6 bolt. The 7 bolt cranks are soft. They were not nitrided from the factory like 6 bolts. First I observed cranks left outside . 7 bolts rusted overnite. 6 bolts take months to rust. Then i discovered the file test. Take a small round file and try to cut in the journals. The file pretty much bounces off the 6 bolts. The 7 cuts like butter.

7 bolt blocks do not tolerate any kind of detonation or low oil pressure because of this. So that is why everyone is ditching them for the more durable 6 bolts. But is this a good idea?

The 7 bolt is superior design in many ways.
The block girdle is far superior design, adds tremendous stiffness to the main caps. The crank is 5 lbs lighter and more oil dynamic. It slices throughthe oil better. The block also comes with a splash pan so the crank doesn't have to slice through so much oil. The journlas are ten percent smaller for slightly less friction. The block IS designed to make more HP.

So where is the future? 7 bolts. All you have to do is nitride the cranks during a build up and you will have a superior block with the same durabilty.

Doing 6 bolt swaps is a pain in the arse. And there are problems. Mitsu no longer sells the 93-94 CAS. The cars will run on the earlier 1G sensors but it triggers a misfire code and is a royal pain in the arse resetting the ecu all the time. They also dont sell the 6 bolt oil bracket any longer. In short its getting difficult to find the 6 bolt parts needed to do swaps.

Unfornately nitriding is not as cheap as I hoped. It cost arond 275 after shipped two ways. Still seems like the way to go if you ask me.

I was going to be a guinea pig for this experiment and go with a built 7 bolt motor. However due to time constraints I opted to go 6 bolt.

 

[tstkl]

i have long wondered about what makes my 6bolt so much better than the 7 bolts, i knew that the rods were thinner on the 7bolts, but this is good information, maybe all us 6 bolt guys will start doing nitrated 7 bolt conversions ....

 

[alex99gst]

thats the first time ive ever heard that theory. i'd like to know what some wisemen on here think about that

 

[HighPsi92GST]

but this is good information, maybe all us 6 bolt guys will start doing nitrated 7 bolt conversions ....

if you already have a 6 bolt why would you waste your time and money on a "supposedly fixed" 7 bolt

 

[Jon_0_3]

whats better to go with then to start a 6to3 bold to a 7 to 4 bolt?