XR4Ti Archived Tech Articles

    Solo II Autocross Classification of the XR4Ti - Information on the classes the XR4Ti is legal for and recommendations for class choice (along with info on how to get in touch with your SCCA region).

Post Date:    Wed, 18 Jul 2001
Subject:      Re: Re: Solo 2 classification
List:         imon@lists.merkurowners.org

Hello all,

Rob wrote:

> I was wondering how to go about entering some Auto X events.
>  Were can i find info on events in my area if there are any ?

If you go to the SCCA's web page and use their Region Locator, you'll get a 
link to a web page (if they have one) and contact information for people who 
can answer your questions.  It's been a while since I've used it, so look 
around.  As I recall, you are looking for a clickable map of the US (maybe 
that's the division locator).  The link is:


The truth is, if my region has a web page, which it does, then it's very 
likely that your region will have a web page as well.

I'd be remiss to leave this email void of Merkur info, so here's what Andy 

> Switched to a roller follower cam with higher lift. Does
> any one know what that would result in for a SoloII
> autocross classification? 

As Grayson aptly replied, any non-stock cam is not legal for Street Prepared 
any more.  It's kinda a shame too.  If I were running DSP here this year I'd 
be annihilating the class that I was having trouble with last year.

Grayson also recommended Street Modified, which is my recommendation (and my 
class, and his) as well.  However, I'll not give you the short reply, but 
some more info on classes available to you.  You could also run your XR in C 
Prepared.  The SCCA lists the XR in the rulebook for CP specifically, but for 
some strange reason, they require the car to be non-turbo.  I believe the 
engine of the XR is well matched to the Mustang engines with their turbo 
(considering weight and other racing-that-involves-cornering considerations). 
 You'd just have to have a well built version of it, over 300 hp.

(Update, March 2002:  The SCCA lists the XR4Ti as legal with a turbo and
restrictor in C Prepared)

The problem with CP, besides the turbo rule, is that stripped interiors are 
allowed.  This means that you'll have your interior and be up against 
stripped cars, or you'll have to strip your interior.

The other class the XR with a cam is legal for is E Modified.  I'm 
recommending against this because your region just might have one of those 
tube-framed monsters.  That's right, tube frames are legal in EM.

So, you see how Street Modified get the recommendation.  It makes a lot of 
sense.  Engine mods are essentially unlimited.  There are displacement and 
forced induction limits and according weight limits (all of them very 
reasonable).  For example, the XR with it's stock engine (as in 2.3 turbo), 
falls into the 3.0 liter forced induction rear-wheel drive category.  We are 
allowed a minimum weight of 2400 lbs.

Keep in mind that while there are driveline and engine configuration 
classifications, you'll compete against everyone in Street Mod.

Regionally, my competition shapes up like this.  I run against mostly AWD 
Mitsubishi Eclipse turbo cars, but also I've raced against an early Jetta, an 
Integra Type R and a Rabbit.

To learn more about Street Modified, visit the SM web page at:


> What about an intercooler?
> Exhaust mod etc.

Both are legal for Street Prepared as long as you don't cut anything to make 
them fit.  They are also legal in SM, CP and EM.


Note:  This is hardly a complete list of mods, nor is it necessarily 
accurate.  Purchase a rulebook from SCCA or your local region to find out 
exactly what you are allowed to do.

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Published by Chris Anglin.