Need Help Selecting "Proper" Auto-X Parts

Fella

Low Mileage
Note: Pics to follow...stay tuned.

Ok. A little background to start.
I have an 82' x that I had originally planned on fixing up as a DD weekend Auto-x'r. Car is to far gone to stick that kind of effort into.
New plan (in the works) is to change this into a Auto-X only tool. THIS WILL NEVER SEE STREET DUTY!!

What I need help with is picking the right combination of parts to make the car as competitive as I can for the XP class.

Power:The plan is to use the Fiat FI 1500 engine that came with the car but needs to be upgraded. What cam, pistons, valves etc will I need to turn this into the fire breather it needs to be?
What mods/parts do I need to make the FI work with the elevated power levels? Is 150hp to tall of an order?
Suspension: Tires will be Hoosier A6's 225/45/13 mounted on 13x8 wheels. What other suspension bits do I need to be looking at? I'm pretty sure I'll need more than just a fresh set of KYB's and cut springs.

Don't be afraid to mention cost.
 
Sounds like a fun racer

Does that class require a cage? Even if not required, the chassis could use the stiffening, and the added safety never hurts.

If the car is never going to see the street again, dump all weight that is not involved in making the car stop, go or turn.

150 hp out of the stock FI computer is too tall an order, yes. You can't run much of a cam with the stock computer, the cheap route would be to switch to carbs. Lightening the flywheel would be a worthwhile mod. The bottom end of the engine will hold up to about anything, not much to do down there. Increase breathing through the head and extend the RPM range to where a larger cam would make power. I can take my full race cam to 7500 or so. Porting the head and intake, race cam and a well-designed header might make 120-125hp.

As for suspension, to be able to do it right and be able to experiment with springs, you need to switch over to coil-overs, which allow standard, fairly cheap 2.5" ID springs. This will not be cheap. Then you have to damp those higher spring rates - this will be even more expensive than the coil-overs. If you are not ready to buy into these big costs yet, a good start would be front and rear anti-roll bars and IAP (or name your vendor) springs. New dampers will help if yours are shot.

Look into brake upgrades. Matt offers a Whoa kit for not too much. Old school method is the PBS modification to make a hybrid Lancia Beta brake system, but this involves fabrication.

But I think the best bang-for-buck is in weight reduction. Think about it this way - if you beef up HP, you only help acceleration. If you beef up brakes, you only help deceleration. If you beef up suspension, you only help cornering. If you reduce weight, you help all 3, and you reduce the wear-and-tear on the parts. Plus, weight reduction is generally free!

Pete
 
To expand a little more...

Suspension wise, for a track only car, go with coilovers. There are many different ways to do this. Ksport offers cheap coilovers, about $1200-$1400 for all 4 corners, Ground Control(?) has some that are pretty pricey if I remember right, more than double the Ksport ones, or fabricate your own from honda (prelude?) coilovers. Add at least a front sway bar.

Brakes, go with Matt's Whoa brake kit for the front, and drilled and slotted discs. But note, if you go with the drilled and slotted discs, and race/performance street or race only brake pads, they typically do not work until they are hot, but once they are hot, they will stop you pretty darn good.

Instead of converting over to carbs, you can always go for a hot cam and do all the normal head work, pistons, lighten the crank and flywheel, get an adjustable cam gear, and replace the computer with a megasquirt DIY kit.

Lowering weight can be simple for a little weight, and can start to get real expensive to really shed pounds. Look at the basics, get rid of the spare tire, remove the dash and center console, remove the gauge cluster and go for just the bare necessities like a tach and temp gauges. replace the seats with lightweight race seats, replace the seatbelts with 4 or 5 point harnesses, if you have AC remove it (I believe Matt has the blank off piece to remove the AC on the engine side) and replace the radiator with a VW Scirocco rad. Get some light weight wheels, and to go real radical and light, replace the windshield with a lexan piece (Matt again) and look into replacing the hood, engine cover and trunk lid with fiberglass pieces (performance fiberglass use to sell these for the X).
 
Does that class require a cage? Even if not required, the chassis could use the stiffening, and the added safety never hurts.
It will have a cage.

If the car is never going to see the street again, dump all weight that is not involved in making the car stop, go or turn.
This car will never again see street use. I'm dumping all the weight I can, but I still have to weigh about 1750 w/o driver.

150 hp out of the stock FI computer is too tall an order, yes. You can't run much of a cam with the stock computer, the cheap route would be to switch to carbs. Lightening the flywheel would be a worthwhile mod. The bottom end of the engine will hold up to about anything, not much to do down there. Increase breathing through the head and extend the RPM range to where a larger cam would make power. I can take my full race cam to 7500 or so. Porting the head and intake, race cam and a well-designed header might make 120-125hp.
Right, I know the stock computer won't be up to the task, but it can it be modded to?

As for suspension, to be able to do it right and be able to experiment with springs, you need to switch over to coil-overs, which allow standard, fairly cheap 2.5" ID springs. This will not be cheap. Then you have to damp those higher spring rates - this will be even more expensive than the coil-overs. If you are not ready to buy into these big costs yet, a good start would be front and rear anti-roll bars and IAP (or name your vendor) springs. New dampers will help if yours are shot.
Anyone have a coil over kit for this? Or is it all custom fab?

Look into brake upgrades. Matt offers a Whoa kit for not too much. Old school method is the PBS modification to make a hybrid Lancia Beta brake system, but this involves fabrication.
I'll look into these.(Whoa kit) However...only work with 14" or larger wheels.

But I think the best bang-for-buck is in weight reduction. Think about it this way - if you beef up HP, you only help acceleration. If you beef up brakes, you only help deceleration. If you beef up suspension, you only help cornering. If you reduce weight, you help all 3, and you reduce the wear-and-tear on the parts. Plus, weight reduction is generally free!
Agreed
 
Last edited:
Stock computer is basically unmodifiable...

I agree with Carl, go the MegaSquirt route if you intend to keep it FI. It will be more costly than switching to carbs, and I'm on the fence as to whether there will be much difference between carb and FI in the RPM range you will be operating in. Down low, or for a street car, I would say that FI is unquestionably the way to go. But for this application, the cost factor might dictate carbs. Or if you really want to get exotic, switch to motorcycle carbs. This might not be legal with the sanctioning body tho. For that matter, the MS computer may not be legal either.

Coilovers are available or you could also fab your own. I went this route, it's documented on www.ferrarikillers.com. Carl mentions several manufacturers if you want to buy rather than make. Mark Plaia (on this forum) also had some available, not sure if he has any left.

Another worthwhile, low-buck mod is switching the final gear ratio to a lower (higher numerically) ratio. Steve Hoelsher (also on this forum) has more details here. You could also weld your spider gears to make a low-buck "spool" rear end.

I have been toying with (and collecting parts for) a truly low-buck conversion for the X1/9 that I think will total about $500-600 (not including dampers, but damper selection will be dictated by spring rates), and will offer these benefits:

- Larger, vented rotors, commonly available
- Commonly available pads
- Strut insert style struts
- Coil-over setup, 2.5" springs
- Built in camber adjustment
- Convert to 4x100 bolt pattern, increase hub-to-hub track (allows far better/cheaper wheel selection for more common FWD offsets)
- Replaceable lower ball joint (rather than replacing entire control arm)
- Replaceable lower control arm to body bushing

Fabrication will be minimal. The conversion will be done to both front and back axles.

I'm only just starting so I'm not ready to share with the whole group yet, but if you want to PM me your email address, I'll send you some pics.

Pete
 
Last edited:
whoa brake's not needed

for autox I have been autoxing an X for over 10 years and not ever uesed the brakes enuf to over heat them.
 
Let me make some suggestions

First off, why not go to DP instead of XP. If you stick with the SOHC 1500 you can stay in DP and be much more competitive.

Either way, all of the following applies:

Lower end: 12:1 pistons from Matt at Midwest/Bayless. Have the 1500 rods shot peened for strength or use Crower Rods. Shim the oil pressure relief spring for a bump in pressure.

Head: Stick with a 1500 head with a moderate port job. Too big will cost you torque. Matt also has some nice cams to choose from. A 40/80 with 10mm lift is the ballpark. An adjustable gear is a necessity as are competition valve springs.

Intake: This motor will have to breath and the OE FI intake won't do the job. And ANY FI ECU that uses an air flow meter isn't either. A megasquirt or aftermarket stand alone is the way to go. You could port an OE FI intake manifold that may get you there but a set of dual 40 DCNFs converted to throttle bodies for use with the megasquirt would be ideal.

I built a similar motor that dynoed at 130+ at the rear wheels on 110 race gas. Peak power was at 7300 rpm and the motor turned 8200 easily.

Matt also has lightened flywheels and you will need a hefty clutch.

The 4 seed axles will not live with this kind of power so you will have to go with a 5 speed. That limits you to a 4.08 gear unless you get a custom R&P. They are out there but are expensive. With those power levels you will need an LSD. A locked rear end isn't a viable option.

Suspension: That's the easy part. Order the struts from G-Force and use 650 lbs/in Front and 450 or 500 lbs/inch rear springs. I can provide you ride height specs when you are ready. Also, do a set of camber plates for adjustment.

Weight: DP is 1.1 lbs/HP. So a 1500cc car would have to weight 1650 plus 75 lbs for the 8" wide wheels. That's a pretty easy number to reach. Cut the windshield, gut the body of all road equipment, skin the doors and do a modest cage.

The above was the basic suspension setup and wheel/tire combo on my multi-championship winning DSP car:

PeruTour3.jpg


Note: anybody that wants a copy of this photo let me know and I can email you the high res version.

ShowField2.jpg


ShowField3.jpg


My Championship winning MR2 runs in DP and its a ton of fun. I had intended to build an X1/9 for DP but the opportunity to do the MR2 was just too much to pass on.

The car:

07Nationals01.jpg


Electromotive ECU:

MR2013.jpg


Crower Rods:

MR2001.jpg


14:1 JE Pistons:

MR2005.jpg


Leda double adjustable struts:

LedaRear.jpg


'08 Championships:

08Nats-westb2.jpg


Nationals08Zack.jpg
 
Steve, I'm curious why you didn't recommend going into GP? Seems like the X1/9 has the best chance of being competitive there.
 
Lots of good stuff to digest...

First off, why not go to DP instead of XP. If you stick with the SOHC 1500 you can stay in DP and be much more competitive.
Yeah, I might seriously consider this. No wing or splitter in DP right?


Head: Stick with a 1500 head with a moderate port job. Too big will cost you torque. Matt also has some nice cams to choose from. A 40/80 with 10mm lift is the ballpark. An adjustable gear is a necessity as are competition valve springs.
Matt sell a race ready head?

Intake: This motor will have to breath and the OE FI intake won't do the job. And ANY FI ECU that uses an air flow meter isn't either. A megasquirt or aftermarket stand alone is the way to go. You could port an OE FI intake manifold that may get you there but a set of dual 40 DCNFs converted to throttle bodies for use with the megasquirt would be ideal.
How about just converting to dual carbs? How does one convert these to TB's w/Megasquirt?


Matt also has lightened flywheels and you will need a hefty clutch.

The 4 seed axles will not live with this kind of power so you will have to go with a 5 speed. That limits you to a 4.08 gear unless you get a custom R&P. They are out there but are expensive. With those power levels you will need an LSD. A locked rear end isn't a viable option.
I've got 5spds. Why an LSD? Why is a locked rear not viable?

Suspension: That's the easy part. Order the struts from G-Force and use 650 lbs/in Front and 450 or 500 lbs/inch rear springs. I can provide you ride height specs when you are ready. Also, do a set of camber plates for adjustment.
G-Forces coilover are nice. But 600 bucks for camber plates? Really? Other (cheaper) options?
 
More answers

Yeah, I might seriously consider this. No wing or splitter in DP right?

Spoiler instead of wing and splitters are permitted but are much more limited.

Matt sell a race ready head??

Yep.

How about just converting to dual carbs? How does one convert these to TB's w/Megasquirt??

Yes, dual carbs would work too but FI is preferred. You could simply buy DCNF throttle bodies but if you had the carbs, simply plug the holes in the throats with epoxy and mount injectors above the velocity stacks. Works great. :)

I've got 5spds. Why an LSD? Why is a locked rear not viable?

You obviously haven't driven an X with a locked diff. :shock:
A locked diff ruins the X's handling. It simply doesn't work.

I am actually thinking that a 6 speed conversion from an Acura RSX Type S would be the ideal X1/9 gearbox. The ratios work out nicely, LSDs are readily available and they are lighter than the X transmission.

G-Forces coilover are nice. But 600 bucks for camber plates? Really? Other (cheaper) options?

Most any camber plate kit will work. The ebay kits for $200 will work fine. I think Mike Soter has a set on his car. Or you can easily make your own. The G-Force kits are intended to work within the DSP rule set. If you are going to Prepared, you can make them much easier.
 
GP

Yes, the X is probably most competitive in GP. But the rule set is very limited. He wanted to run 13x8 wheels with A6s. You can't do that in GP at all, you can in DP. I don't see much attraction for GP. Heck, I was typically way faster with my DSP car than DP.
 
Yes, dual carbs would work too but FI is preferred. You could simply buy DCNF throttle bodies but if you had the carbs, simply plug the holes in the throats with epoxy and mount injectors above the velocity stacks. Works great. :)
Write up or website explaining this? Sounds cool.



You obviously haven't driven an X with a locked diff. :shock:
A locked diff ruins the X's handling. It simply doesn't work.
Shhhh....Don't tell anybody, but I haven't driven an X period.:((please don't hate me):laugh:

I am actually thinking that a 6 speed conversion from an Acura RSX Type S would be the ideal X1/9 gearbox. The ratios work out nicely, LSDs are readily available and they are lighter than the X transmission.
Couple of questions on this...1) Anyone doing/done this? Kit? 2) Would this be legal if I play in DP instead of XP?

Speaking of LSDs, what's available for the stock 5spd unit?
 
the best thing

you can do right now is go drive and race your car the way it is before you start putting racing parts on it.

not only do you need the experience the car needs a good shake down to find out what needs to be replaced before putting racing parts on it like discovering you have bad ball joints wheel bearings or bushings.you will not be able to get the car to have an accurate and consistent alignment with bad parts

Have you ever been to or raced an autox event before?

ware are the events held in your area (Shawano)?

If you can get down hear to the Chicago land area you can go to autox events with me. My friend Bob and I
are going to an event on 7-26-09 common down it will be .
 
you can do right now is go drive and race your car the way it is before you start putting racing parts on it.
No can do. This was not a driver when I got it. Car is now in shell form awaiting sawzall.
not only do you need the experience the car needs a good shake down to find out what needs to be replaced before putting racing parts on it like discovering you have bad ball joints wheel bearings or bushings.you will not be able to get the car to have an accurate and consistent alignment with bad parts
The plan is to replace with all new prior to alignment.
Have you ever been to or raced an autox event before?
I've had Miatas ranging from E-stock to SM2. My SM2 car was a 05' MazdaSpeed Miata. Suspension was stock, motor was not. I ran 225/50/15 Kumho V710's. Won a couple of events. Yep, I've crossed before.:) Never in real prepped equipment.:(

ware are the events held in your area (Shawano)?
Minneapolis/St Paul area & LAX

If you can get down hear to the Chicago land area you can go to autox events with me. My friend Bob and I
are going to an event on 7-26-09 common down it will be .
I do plan on getting to Milwaukee in the future.
 
More Answers

Write up or website explaining this? Sounds cool.
?

I did this converstion for somebody else, years ago, before you could buy DNCF throttle bodies. Its not hard. Buy the largest chokes available, remove the venturis and fill the holes in the bores, along with the accel pump nozzel holes with epoxy and then blend the epoxy when it sets up.

You can buy injector mounting rails and fab a simple mount to locate them just above the velocity stacks. This is the preferred location for modern systems. In one installation I saw, the injectors were mounted to a rail suspended from the under side of the air filter top. The injectors stuck through the top where the fuel rail was mounted to the top of the filter cover. Very slick.

Shhhh....Don't tell anybody, but I haven't driven an X period.:((please don't hate me):laugh:
?

Then you are in for a treat my friend. My blue DSP X was the best racecar I have ever driven. No exceptions. And that includes a number of purpose built racecars, including an '08 Porsche GT3 Cup.

frontquarterview440px.jpg


Yes, I said the BEST racecar I have EVER driven.

Couple of questions on this...1) Anyone doing/done this? Kit? 2) Would this be legal if I play in DP instead of XP?
?

No. I have built a few of these transmissions and found them to be very nice units. I think they could be adapted fairly easily by fabricating a bellhousing adapter. The transmission is free in DP.


Speaking of LSDs, what's available for the stock 5spd unit?

There are few options and even fewer units available. The Colotti is about it and you will have to find a vendor in Italy to buy one. There are some used ones in the US if you can turn one up.

Its the lack of alternate gear ratios and LSDs is why I thought that adapting the K20 gearbox was a viable option. You can probably make the adapter for the cost of an aftermarket R&P for the Fiat box. Once you have the adapter done, you have lots of options that you don't with the fiat box.
 
Back
Top