checking stall speed

[turbojoe]

I have a mostly stock (bolt ons) 86 ttype. I am interested in checking my stall speed as I am suspicious of whether I have a stock D 5 or a replacement. When visually inspecting converter, I do see the D 5. However when checking the stamped D 5 with the picture over at GNTTYPE.ORG it appears to differ. On mine, the D and the 5 are not stamped the same size. The picture on website shows both the D and 5 stamped same size/height. Should I be concerned? Car does seem to have a bit of lag from a standstill for a stock turbo. I think I read some where that you can test your stall speed by applying the gas while holding brake pedal until you just reach into boost or until tires start to spin. Upon doing so look at tach (scanmaster preferred) to check the rpm at which it occured (tire spin) to gauge the stall speed. Any ones help with this would be much appreciated! :smile:

 

[Dusty Bradford]

I have a mostly stock (bolt ons) 86 ttype. I am interested in checking my stall speed as I am suspicious of whether I have a stock D 5 or a replacement. When visually inspecting converter, I do see the D 5. However when checking the stamped D 5 with the picture over at GNTTYPE.ORG it appears to differ. On mine, the D and the 5 are not stamped the same size. The picture on website shows both the D and 5 stamped same size/height. Should I be concerned? Car does seem to have a bit of lag from a standstill for a stock turbo. I think I read some where that you can test your stall speed by applying the gas while holding brake pedal until you just reach into boost or until tires start to spin. Upon doing so look at tach (scanmaster preferred) to check the rpm at which it occured (tire spin) to gauge the stall speed. Any ones help with this would be much appreciated! :smile:

That is the easiest way to check stall speed. Foot brake the car to 0-1# of boost and check the rpm with a scan tool. If it can't reach 0-1# before spinning the tires it may be a Monte Carlo D5 which will have a really low stall speed. Like 1200-1400.

 

[turbojoe]

Dusty, Let me get this straight. I should be at threshold of boost or 0-1 psi before tires begin to spin? And if they are to spin prior to nearing onset of boost, then it may be wrong converter (possible monte carlo)? What should stall speed rpm's be for the correct D5 converter? My guess is around 1800 or so?? Thanks for your assistance.

 

[Dusty Bradford]

Dusty, Let me get this straight. I should be at threshold of boost or 0-1 psi before tires begin to spin? And if they are to spin prior to nearing onset of boost, then it may be wrong converter (possible monte carlo)? What should stall speed rpm's be for the correct D5 converter? My guess is around 1800 or so?? Thanks for your assistance.

You should be able to reach 0-1# of boost before the tires spin unless the converter is super tight. If it spins before you reach 0-1# of boost see what the rpm is at that point and how close to 1# of boost you are.

Most stock D5's will stall around 1600-1800. The Monte Carlo converter is a common mistake made by the local trans shops. The cars I have tested with these converters will make about 3-5psi but will not go any higher no matter how good the brakes are, even with assisting the stock brakes with the emergency brake.

 

["Turbo-T"]

Dusty, is there any other way of verifying if one has a D5 from a monte? (visually)

 

[Dusty Bradford]

Dusty, is there any other way of verifying if one has a D5 from a monte? (visually)

I don't think so. The stall test is the only way I can tell.

The only time I have seen these installed is when guys deal with the local trans shops. They order a new D5 and it's most likely for a Monte Carlo.

 

[turbojoe]

If someone was to post a picture of stampings (D5) on case that might help. Maybe post stampings of a monte D5 and also a GN D5 to compare.The pics on GNTTYPE.ORG show the turbo buick/GN D5 and the stamping of the D5 are large case letter/number. The D5 converter in my car is stamped with I think a lower case d and the #5. I will have to double check though, as I could have it backwards. Either way, I don't know if the stamping is evidence of which converter it is. I still have to check the stall speed by engine braking the car, as I did not have much time this past week. I will post results when completed.:smile: