# OBD1 VR6 630cc Chip Final testing complete.



## scarboroughdub (Jul 8, 2002)

As some of you may have heard through the vw gods, i have finished testing my OBD1 VR6 630cc chip tune.
Car in question:
1995 GTI VR6
630cc injectors
4 inch maf housing
3bar fpr
GT40 turbo
Stock motor. will be going full internals soon.
60mm wastegate
13psi
I have been working on this tune for just over 2 months now.
Initially the car ran great but a tad rich at idle, but after some more work within the bosch code i was able to locate the final parameters that allowed me the solve that issue.
As of now the car is on the road driving. and boosting







.
No hiccups, no weirdness just drives.
Now i know the power isnt 630cc material but this was done to show proper fuel and timing control is possible with obd1.
enough talk here is the graph.








and hp vs tq









http://****************.com/smile/emthup.gif 

Car in question:

















_Modified by scarboroughdub at 11:27 AM 4-23-2009_

_Modified by scarboroughdub at 11:36 PM 4-23-2009_


_Modified by scarboroughdub at 1:50 AM 4-26-2009_


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## MrMoon (Dec 23, 2008)

*Re: OBD1 VR6 630cc Chip Final testing complete. (scarboroughdub)*

very interesting, i have been hoping for an update from you
I still have to get my ecu code...
what psi was that at?


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## Noobercorn (Aug 17, 2007)

*Re: OBD1 VR6 630cc Chip Final testing complete. (MrMoon)*

good work!!


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## NeverEnding... (May 9, 2007)

*Re: OBD1 VR6 630cc Chip Final testing complete. (scarboroughdub)*

are you using a different MAF? because if not then u havn't really pushed the limits of the stock one to really TEST what the 630's can actually do when running higher boost and making 500+whp...cuz the stock MAF deffinatly can't handle that kind of power...im sure u already know this if u were able to write your own software, but i was just curious what MAF u were using


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## MrMoon (Dec 23, 2008)

*Re: OBD1 VR6 630cc Chip Final testing complete. (NeverEnding...)*

it can handle that much power, it just cant read over about 400 so it has the injectors go to max duty cycle and then you tune w fuel pressure & boost


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## benzivr6 (Feb 16, 2001)

*Re: OBD1 VR6 630cc Chip Final testing complete. (scarboroughdub)*

Nice work http://****************.com/smile/emthup.gif


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## corrado-correr (Jul 8, 2004)

*Re: OBD1 VR6 630cc Chip Final testing complete. (MrMoon)*


_Quote, originally posted by *MrMoon* »_it can handle that much power, it just cant read over about 400 so it has the injectors go to max duty cycle and then you tune w fuel pressure & boost

does that explain why the AFR's dip a little beyond 4k rpm?


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## MrMoon (Dec 23, 2008)

*Re: OBD1 VR6 630cc Chip Final testing complete. (corrado-correr)*

i don't think thats it, the maf should still be able to read at that point but im not the expert, lets wait to hear from radek


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## scarboroughdub (Jul 8, 2002)

*Re: OBD1 VR6 630cc Chip Final testing complete. (MrMoon)*

At that power level there is still plenty of head room on the voltage range of the maf.
yes the biggest issue is maxing out the stock maf, even in a bigger housing, but no fear i got 2 solutions i am working on, one is a maf from a different application, good to 700hp and the other is the stock maf sensor.
Its currently on my bench ripped appart, dont ask how i did it, and i am reworking the circuitry to give us the head room we need.

As for fuel pressure tuning, thats no way to tune. especially in a oem system.

My biggest issue with this size injector was getting injector timing low enough to have proper afr's at idle. now that i attained that control. its just a matter of maf sensor testing to really max out those 630's.
Thing is alot of tuners. mod maps and dont really sit down and break down the code. So eventually you hit a limit in the software that will not allow you to control fuel beyond a certain point.
now you would think what limit, well a stock injector works alot faster at idle then a bigger sized injector. so to attain the same afr we need to go beyond the limits that were originally put in place by the factory, but werent really being hit in stock trim.
Just for sihts and giggles, i may test some 1000cc injectors in the near future once i have the 700hp capable maf setup. probably no one will use it, i just want to see how far this good old bosch box can go.
lets have some fun before those electric cars take over.


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## V-dubbulyuh (Nov 13, 2005)

*Re: (pubahs)*

Sweet thread... should have seen this prior to my OBD2 swap.


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## scarboroughdub (Jul 8, 2002)

*Re: OBD1 VR6 630cc Chip Final testing complete. (scarboroughdub)*

Thanks for the kind words guys.
At this point i am hoping to finalize the tune and have it ready within a week.
When i say finalize i mean really put it through some serious testing.
WOT throttle tuning, as seen on the dyno isnt too difficult, its the daily driveability that i am really anal about, in my books it has to be close to perfect or else i wont release it.
the car in the picture is running a BOV, which is a no no. customer is switching to a Diverter this week, this should solve the occasional hiccup on fast down rev.
I will keep you guys informed, as i have a couple test vehicles so 630cc inj and 440cc inj software is being tested.


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## V-dubbulyuh (Nov 13, 2005)

*Re: OBD1 VR6 630cc Chip Final testing complete. (scarboroughdub)*


_Quote, originally posted by *scarboroughdub* »_
I will keep you guys informed, as i have a couple test vehicles so 630cc inj and 440cc inj software is being tested.










My mouth is watering.


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## Nuzzi (Oct 18, 2001)

*Re: OBD1 VR6 630cc Chip Final testing complete. (V-dubbulyuh)*

any updates on this??


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## instg8r (Sep 22, 2003)

*Re: OBD1 VR6 630cc Chip Final testing complete. (Nuzzi)*

i'd interested in a 440 tune, so long that it idles properly, and that it cold starts, cold run properly


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## scarboroughdub (Jul 8, 2002)

*Re: OBD1 VR6 630cc Chip Final testing complete. (instg8r)*

idle and cold start was the first thing i worked on the longest as i feel it is most important, making power is easy. Normal running conditions are the harder part.
Pm therealgreco he will gladly share his 42lb tune experience with you.


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## instg8r (Sep 22, 2003)

*Re: OBD1 VR6 630cc Chip Final testing complete. (scarboroughdub)*

will do.


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## IHookItUuup (Aug 6, 2008)

*Re: OBD1 VR6 630cc Chip Final testing complete. (instg8r)*

Brilliant Work!


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## MrMoon (Dec 23, 2008)

*Re: OBD1 VR6 630cc Chip Final testing complete. (IHookItUuup)*

so the 440cc tune is done, how is the 630cc tune coming along?


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