Estimated spool up time with (2) t-76

[TURBOZ]

Right now I have a T76 that I used. I ran into too much back pressure with one. Right now there are a few floating around, I was thinking of getting another to make twins. My car is a 383 with a 6spd. I spoke with turbo people and they said that sounds like a good idea. How long do you think it will take to spool 2 T-76 turbos with .96A/R?

 

[1320]

to much back pressure?

How much time? well with the 6 speed you can t power brake it..........or teans brake it for that matter......

From a roll............a slightly modded supra would get nice head start.

 

[TURBOZ]

Yes I could not make more then 10-11 psi because my back pressure was 1/3ratio. Everything was set up correct, too much motor for that a/r. If I used two of them i would not have any problems, however I would like the turbos to come on before 60mph. First gear with little boost would be great, no tire spin, then if the turbos would come on right around 40-50 that would be perfact! NO NOS
Im only thinking of doing this because no body seems interested in my T76. If I sell it I will go with TE62's

 

[1320]

I tend to lean towards another problem.....I ve never even heard of such a problem.....If the motor was to much for it ..it would spool very fast and boost like crazy in the lower rpm.....should still be easily capable of lifting the heads.....In some cases when a turbo is to large the exhuast volum is to small to reach the efficiecy point of the turbo.....thus limited boost output....

How much for the 76? ball bearing?

I know several guys running twin 66's making in the 1500 hp range......conley was running twin 76's on his car ( i don t knowif he still is) and that was on a 447 bbc with big heads....big converter.....and 6.60 @ 210 et's....

 

[EightSecV6]

Conley has a Lenco (clutch ,no convertor), put a 2step on it and plant it to the floor, it will spool LIGHTNING fast with a clutch as long as the ECM is programmed for it. To small of an A/R will cause much back pressure and boost control problems, high back pressure will also help you destroy your head gaskets!!!!
Bill Anderson

 

[TURBOZ]

Im looking to get $1100 for the turbo. Here are some picts of it. Its not a ball bearing.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1862859920

 

[Winsett]

I spool a pair of 63's in a reasonable time frame... about 4/10ths of a second with a lenco and a clutch to 18lbs currently- is your issue getting it spooled up and ready for a run or spooling it up rolling? Both ways it can be done and you have more than enough motor to do both. What are you using for fuel management?




Winsett
www.meankidsracing.com

 

[TURBOZ]

I would probably have to get a smaller exhaust housing to make the 76's work huuu? .96a/r too big? Im running a FAST for fuel management. The car is mostly a street car, so spooling out of the hole is not much of an issue. The car is good to about 1200hp. I was told by precison that the car would be no fun because the turbos would not come on till 70-90mph..

 

[Winsett]

Who am I to question them guys at Precision =) but -- I think that it would be fun to drive - and I am sure that it would be more than effective giving the right tune. I too have the big housings - what size are your headers and down pipe(s)? If this is a street car then I assume you have something similar to the current rage M6 that all the faster guys are running with in the f-body crowd. (Either way) You shouldn’t have any issues spooling them 76’s. There are more than a few fast street cars (600-800hp f-body’s and vettes running around with super chargers with manuals) the way I look at it is this - 'most' low compression motors are pigs until they get motivated buy something in our cases the motivation is the same 'boost' - the trick is where and when you are able to get it and use it. Getting to it down low is easy if you figure it out for you combo - using it may be your down fall - you will loose all boost at every shift - meaning - shift {straight to 0 vacuum back to boost} every time you shift. When you release the load on the motor you loose the motivation and have to get it back and when you get it back it comes on… This could make for disaster in a high horsepower street application. Clutch in and out, power on and off does a hell of a number on the suspension and the rear tires on a street car –


That’s really not the topic and I am sorry to get off base – obviously if you are going to try and run the same power level with this combo that you have with the 76 but are interested in going with twins you would want something that you can spool – I would ‘guess’ that you could spool the pair of 76’s with the right tune with no problems with a 383ci motor and a manual - there are a few 270+cubic inches that spool 60-70ish sizes with autos - I only know of 2 Buicks running manuals - myself and Billy Anderson, and while our combos are night and day different the power application is somewhat relevant. There are peeps that are running similar combos to what you have. I would ask them as well.




Winsett
www.meankidsracing.com

 

[TURBOZ]

My plan is to go with twins just because there is only a few guys in the country with twins on a fourth gen. There was a kit made, I dont like the design of low mount turbos. Im going to design my own kit, making high mount turbos.I called several shops telling them my goal was to make 900rwhp. Telling each shop my situation, precision said(2) T76 too big as I state before. They recommend two PTE 52's, pricing $775 a piece. I called Innovative who made my T76 I have now. They recommend two T63 or T66's, I dont think I asked them about using twin 76's. The price was about 1200 a turbo through them. Then I called turbo people first telling them my back pressure issue and stating I want twins. The guy there said, "I would throw another 76 on the car...I called turbo people back a week later not telling them who I was, just saying I want twins and the ability to run 900rwhp on the street and if I ever hit the track maybe turn it higher. They recommened twin T70's. My last call was to John at limit enginering. He recommend twin TE 63's at a unbeatable price of $630 a turbo I was ready to order these turbos but my turbo never sold on ebay. So now im left with a T76 and a racegate. I would not mind using the turbo I have now, but a few things im conserned about. One will I have to get a smaller exhaust housing? Two will I beable to turn the car down enough to make 700rwhp? Three Im thinking twin 76's will end up costing me $1000 more then I have to.I dont want to spend a Sh$t load on turbos that I will never use the power potensial, but at the same time have some room for development....

 

[Winsett]

right - all of that sounds about right. I have 63's and I have a little over 700 to the wheels I have learned that turning the car down is harder than turning it up...


76s are big - thats a given -- I have the 81 housings on my car and like I said I dont have any issues.




good luck


Winsett
www.meankidsracing.com