is a mk2 16v competitive?

[Beran]

Here in the NE a 16v is not competitive in ITA no matter how much prep you give it.
I have been racing and building VW's since 1993. We converted a number of 16v's to 8v to compete in ITB where there are competitive. I think it's a very easy change... just change the head.
VW's are very durable and very cost effective to run.
Having said the above, it depends upon who shows up and what the talent of the VW and other competitors driver skill is. But on average it is at a performance disadvantage.
Here in the NE we do use stock cams and cams cannot be "closed up" since the rules do NOT allow this ;-)
Although no one has really tried to use a custom map system yet with the 16v - maybe this might give it more of an edge. Any thoughts?

[Bill Miller]

Here in the NE a 16v is not competitive in ITA no matter how much prep you give it.
I have been racing and building VW's since 1993. We converted a number of 16v's to 8v to compete in ITB where there are competitive. I think it's a very easy change... just change the head.
VW's are very durable and very cost effective to run.
Having said the above, it depends upon who shows up and what the talent of the VW and other competitors driver skill is. But on average it is at a performance disadvantage.
Here in the NE we do use stock cams and cams cannot be "closed up" since the rules do NOT allow this ;-)
Although no one has really tried to use a custom map system yet with the 16v - maybe this might give it more of an edge. Any thoughts?

Not exactly Beran. Putting a GX (8v) head on a PL (16v) bottom end will give you ~13.5:1 CR.

[GTIspirit]

Although no one has really tried to use a custom map system yet with the 16v - maybe this might give it more of an edge. Any thoughts?

I've been considering this from an academic perspective for a while and cannot figure out how this can be done with off the shelf ECU hardware. The PL engine with CIS-E does not have a toothed crank wheel, only a hall effect cam sensor. So I don't know how one could install an aftermarket ECU to run fuel and spark, as allowed by the new IT rules. (Well, it was allowed before, just had to be within the stock box.)

If you can write the software I have thought of one way to do it easily. And that is to have an ECU read in a wideband O2 sensor and then based on a map of say engine load and rpm, output a simulated switching O2 sensor to bias the DPR as desired. Essentially intercepting and fooling the stock O2 sensor input. But this would only work for closed loop operation, not open loop.

There is one other way, and that is to remove the CIS-E unit and run the DPR control out of a programmable ECU. But again, that only affects closed loop operation and not open loop.

So the new ECU rule is useless to those of us with mechanical fuel injection and no stock toothed crank wheel. Since the new open ECU rule doesn't benefit everyone, I wonder if the SCCA would consider a clause to allow sensor/actuator parity to go along with the open ECU rule? Probably not.....

[Andy Bettencourt]

...I wonder if the SCCA would consider a clause to allow sensor/actuator parity to go along with the open ECU rule? Probably not.....

This has actually been a topic of conversation recently on the ITAC.

[GTIspirit]

Hmmm, I think we've strayed a bit off topic talking about the open ECU rule in this thread. Even if there is such a discussion in the ITAC, I don't ever see them allowing mechanical fuel injectors to be replaced by electric fuel injectors, distributor being replaced by coil system. That would also be necessary to create parity with cars that are so equipped to take advantage of the open ECU rule. Otherwise just allowing a standard sensor set, i.e. to include crank and cam wheels and associated sensors wouldn't really give us all that much.

But back on topic, I wonder how much a programmable ECU would benefit a PL engine to make the Mk2 16V competitive in ITA? I'm not convinced it would gain a whole lot over a CIS-E system in good working order.

[Beran]

Bill - thanks for the correction/data regarding 16v & 8v. I guess the motors need to be completely swapped.

[shwah]

The distributor has a 4 window hall effect sensor, which can be read by some fuel injection computers effectively as engine speed (though not as nice and accurate as a multi tooth wheel).

Controlling the CIS-E can be done, but no one has gotten there yet. We are taking a non-IT useable route on a production car, and for my 8v I would rather loose the extra weight of the CIS-E parts and gain the more readily available parts of the Digifant on my conversion, so I won't be figuring it out right now.

[vwcorvette]

SO...digi conversion is legal for IT? I've done this on my DD passat 16v and love it. But it seems week down low.

[jlinfert]

SO...digi conversion is legal for IT? I've done this on my DD passat 16v and love it. But it seems week down low.

Since the VIN rule is gone, yes you could convert a CIS-E 8V car to digi and then use an aftermarket ECU to contol it (Megasquirt would work well). I suspect a properly done MK2 digi car with an MS system would be VERY competitive in ITB.

[shwah]

Digi conversion (or converting digi to CIS-E) has always been legal for the 8v cars because the spec line includes both systems. The vin rule being 'fixed' means you can now turn an 16v into an 8v and vice versa.

[mgyip]

Just a quick update - after what I've seen this w/e, the 16v GTi in 1.8l trim simply is NOT competitive in ITA. In other words, whomever is building one can either spend s**tloads of money to bring it to mid-pack or just spend their money more wisely and purchase either a Miata or a Honda product.