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Cal-look/High Performance => Pure racing => Topic started by: mr horsepower on April 26, 2016, 07:36:41 am



Title: what launch rpm on turbo car
Post by: mr horsepower on April 26, 2016, 07:36:41 am
Hi loungers i need to know the launch / boost rpm on a vw turbo car
So i can calculate my new converter
I am looking around 3000 but maby that is to low.?

Thanks gr henri






Title: Re: what launch rpm on turbo car
Post by: richie on April 26, 2016, 07:45:31 am
Henri,

Typically I launch at 6800rpm, but there are so many variables like turbo size/cam/heads etc, there is no way I could launch at 3000rpm, it wouldn't be making boost. You really need some idea of where engine is on cam and making boost 1st to decide that

cheers Richie


Title: Re: what launch rpm on turbo car
Post by: mr horsepower on April 26, 2016, 07:54:51 am
Hi Richie i have a launch option on my ecu
And i can give the amount of ign retard to get the boost up
I need boost to launch and enough rpm to drive fast.
So i need to boost it at a lower rpm then usual .
I think with a v8 it is easyer  to do then a 2.2 vw
So need to figure something out
Also still got the nos bottle?

Gr henri


Title: Re: what launch rpm on turbo car
Post by: richie on April 26, 2016, 08:28:46 am
Hi Richie i have a launch option on my ecu
And i can give the amount of ign retard to get the boost up
I need boost to launch and enough rpm to drive fast.
So i need to boost it at a lower rpm then usual .
I think with a v8 it is easyer  to do then a 2.2 vw
So need to figure something out
Also still got the nos bottle?

Gr henri

Even taking lots of timing out if the turbo doesn't spool down there already it will take much too long to spool up, its something all the V8 automatic turbo pro mods have problems with as well, if you watch and listen to them trying to make boost and stage the car its a real pain, if you size turbo ok you can do it but then it will run out higher up, you can use the nitrous to help it spool quicker

cheers Richie


Title: Re: what launch rpm on turbo car
Post by: modnrod on April 26, 2016, 10:22:05 am
Not on a VW, but I used anti-lag on the line and a lower converter rpm than normal, but this was a streeter not drag.
It gave me good launch on street tyres but without blowing the tyres off, but the extra boost built very quickly and it was out the door.


Title: Re: what launch rpm on turbo car
Post by: BeetleBug on April 26, 2016, 11:27:21 am
How long is a rope? It is surely longer than 3000 rpms no matter what.

My car/engine is notorious difficult to launch properly. My engine is tiny, my exhaust is too big, my turbo is WAY too big and my car is a heavy street car. It is a balancing act to get it to leave the line properly without bogging. I use ALS as well and I basically torture the living hell out of the little mouse. On a good strip with good temperature I add clutch slip before I adjust boost and launch rpms and what I typically see is between 6300 and 6900 rpms @ 1.6 - 2 bar of boost with my MH DOT 215 tires. 1.44 - 1.55 60ft.

-BB-


Title: Re: what launch rpm on turbo car
Post by: mr horsepower on April 27, 2016, 13:59:17 pm
So  3000 is way to low.
I need to make a proper transbrake to get it on boost cant hold it on the drumbrakes
But  ritchie is right about the pro mod cars
The difficulti is that turbo s like stall converters verry much
They act like an waterbrake
I know i got a lot of balance work ahead of me to make it work
But i recon there is a guy in the states he has a red color new beetle
That also has an  automatic in it does anyone got some info om that car ?

Gr henri


Title: Re: what launch rpm on turbo car
Post by: Chip on April 27, 2016, 16:49:57 pm
The front engine Doug Harvey car?


Title: Re: what launch rpm on turbo car
Post by: mr horsepower on April 27, 2016, 18:48:08 pm
The front engine Doug Harvey car?

Al i know that it was a red car
Could be

Gr


Title: Re: what launch rpm on turbo car
Post by: Chip on April 27, 2016, 18:55:30 pm
The one I'm thinking of is a front engine setup. Probably won't be of much help to you.


Title: Re: what launch rpm on turbo car
Post by: mr horsepower on April 27, 2016, 19:38:30 pm
The one I'm thinking of is a front engine setup. Probably won't be of much help to you.

Ok .
But it runs good so it is possible

Gr henri


Title: Re: what launch rpm on turbo car
Post by: Neil Davies on April 27, 2016, 21:49:08 pm
Didn't Ron Greiner have a T25/vanagon automatic gearbox in a turbo drag bug a while back? An olive drab green '67 if I remember right.


Title: Re: what launch rpm on turbo car
Post by: Chip on April 27, 2016, 22:47:34 pm
http://www.thesamba.com/vw/classifieds/detail.php?id=1870270 (http://www.thesamba.com/vw/classifieds/detail.php?id=1870270)


Title: Re: what launch rpm on turbo car
Post by: richie on April 28, 2016, 13:08:30 pm
As far as I know Frallan has about as much knowledge on this as anyone for rear engine stuff, be worth sending him a PM

I think the New beetle leaving with about 800hp is completely different animal so no gains from that set up

cheers Richie


Title: Re: what launch rpm on turbo car
Post by: Berger on April 28, 2016, 13:32:30 pm
I think it would be wort the effort to take your engine to the dyno and do some testing. Then you can find how low you can go and still build boost. Then calculate by the measured hp/torque/boost to see if those figures fits your goal. Better than taking a chance on a to low/high stal speed. Mine has a "two step" type of set up, and at launch I have the hard cut rpm limiter at 5000rpm, builds boost quite fast hitting the limiter.


Title: Re: what launch rpm on turbo car
Post by: mr horsepower on April 28, 2016, 19:49:59 pm
Thanks guys for your input on this
I notice that it is not an easy route i am walking
And learned that a vw need a lot of rpm to build boost when staged
And to get the car of the line verry fast wil take a lot of trail and error
But i am dertermine to do it.
First i drive the car n/a this year and do some dyno and dragrace
To learn and gather data .
Then i wil put a turbo and charge cooler on it then drive it again and gather data
Then the transbrake and by that time i hope to have enough info
To build me a proper converter
And mayby try somthing different like switch pitch or controled fill on the torque converter
But i am happy that i come thisfar  and i can tune my car
I wil go for that so my cvt 8 speed  transmission plan for a vw bug is going in the fridge

Gr henri


Title: Re: what launch rpm on turbo car
Post by: Garrick Clark on July 13, 2018, 17:19:16 pm
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