We bought our first xr. Autox/street machine in the making.

[hEaT]

Consider me schooled. Great info, thank you.

[catapultkid]

A lot of time has been spent on this car over the last month or so and it has finally come together.

I had an issue with burning oil, the can be read about more indepth HERE, but basically it was the large cam on stock valves. It was eating away at the valve stem seals causing a lot of smoke. This in turn did damage to the turbo, and wideband sensor.



After that was sorted I came across a PiMP engine management system on c'list by accident. This prompted an immediate upgrade.

This install can be read about HERE



A couple of quick highlights are

New catch can:



Cleaned up the boost pipes and added a new sensor. Along with a new BOV that didn't leak like the stock DV did.









This last Friday night it came together and a friend, wife and I went to the drag strip to further tune the car.



Spent a lot of the time on the laptop slowly adding boost until we reached about 14 psi



Added boost using the homemade MBC. I did it not by tightening the spring but taking a dremel with me and enlarging the hole.





I thought I had made it home free until the car started getting loud on the inside. Busted motor mount.



Autox was also this weekend so something had to be done quick. So solid mounts it will be.

Removing old.



Should do the trick...



Some grade 8 hardware and it was done.





Because racecar....

[catapultkid]

First autox with the new setup complete. This time it made it back in one piece.

First the few pictures I have below. Lots of time worrying about the tune, no effort spent on tire pressures, alignment, the "line", or struts? It was about getting it there and back in one piece.





This setup came in super handy for keeping the laptop supplied with power.



Every run a little fuel was added or subtracted here and there in the table. Then played with some of the other features of MegaSquirt.







Things we liked:
1. Car stayed together
2. Initial turn in was tight and very predicable
3. Seating position and wheel where a nice addition.
4. Awesome exhaust/BOV note of a turbo 4 cylinder... when your outside of the car.


Things we didn't like
1. Car pushed too much, partially due to the lifting of the inside front wheel in mid corner and also because of the lack of camber/caster.
2. The brakes where horrible, but that was completely expected and known upgrade we need to make.
3. Lack of power, not so much overall but having to wait until 4k-4.5k to get it was really annoying. This wasn't the case with the old turbo and tune so we are looking into this pretty hard.
4. Didn't build boost on launch without 2 step. This needs to be added soon. Yay more noises.


Lastly it was really nice to see another xr4ti running at the club, Greg Larson drove 3 hours to show up am I'm glad he did. A lot of fun watching him drive in another xr and getting to meet him. Hopefully it won't be the last time. Here is a shot of him driving.




So here are my questions and I'll break them into two parts setup and engine.

Setup:

I've got 350lb springs in the front with something "soft" in the rear. The car, as mentioned above, lifts the front wheel in mid corner and starts to push. I personally think this is because of the soft rear springs, but I want to know what others think. I know lift like this is traditional on many cars but usually it is just before corner exit in my experience. What are others running in the rear?

I also need a bunch more camber and caster. Only the outside of the tires where remotely warm (hoosiers r6s and lots of wait time didn't help). I hope to do some of this with Scorpio LCAs a friend has on hand.

Engine:

I think there is something wrong/not completely tuned correctly for the turbo. Its a t3 .60/.63 and it isn't building full boost until 4k-4.5k as mentioned. I do realize I have a bad intercooler position and a small exhaust elbow but the last turbo didn't behave like this. I think I need to rebuild my stock unit and run the smaller stock exhaust side and run a larger cold side along with more than 14psi. I do 100% left foot braking and I found even with leaving my foot on the gas it was still too much of a delay to swallow. Right now I'm looking into first setting it up with 2 step launch. Then into anti-lag or other tuning ideas.

[DSPXR4ti]

Setup:

I've got 350lb springs in the front with something "soft" in the rear. The car, as mentioned above, lifts the front wheel in mid corner and starts to push. I personally think this is because of the soft rear springs, but I want to know what others think. I know lift like this is traditional on many cars but usually it is just before corner exit in my experience. What are others running in the rear?

I also need a bunch more camber and caster. Only the outside of the tires where remotely warm (hoosiers r6s and lots of wait time didn't help). I hope to do some of this with Scorpio LCAs a friend has on hand.

Engine:

I think there is something wrong/not completely tuned correctly for the turbo. Its a t3 .60/.63 and it isn't building full boost until 4k-4.5k as mentioned. I do realize I have a bad intercooler position and a small exhaust elbow but the last turbo didn't behave like this. I think I need to rebuild my stock unit and run the smaller stock exhaust side and run a larger cold side along with more than 14psi. I do 100% left foot braking and I found even with leaving my foot on the gas it was still too much of a delay to swallow. Right now I'm looking into first setting it up with 2 step launch. Then into anti-lag or other tuning ideas.

I'll ask some question first:
1. are you running the stock brakes still, if not what rear calipers are you running?
2. you need 650 lbs rear spring or better but no more then 800 lbs because I don't think the koni's can handle 800 lbs springs. Another thing is what do you have the rear Koni's set at? if you have the rear Koni's set to full stiff, they are rebound only and will hold the rear of the car down (front tire lift) until you hit a straight or the next turn.
3. after you put the Scorpio TCA's in, check your camber and reset toe, also what's your tire PSI?, with camber in the 2.0 to 2.5 range, you should be 38 to 40 psi for the front tires and adjust your rear PSI to feel.
All this will help and keep working at it.

Engine wise:

This is what I thought was going to happen and why I didn't go with the .63 exhuast housing, Yes maybe could get 400 hps with the .63 housing but to what gain, I mean if I can get 325+ hps come in at 2800 rpms with a .48 or get 400 hps at 3800 rpms with a .63 where that going to help on a autocross course. Yes you can adjust with gearing but then if you have to shift because now your out of gearing, same thing, I can go on and on but lets not. Go back to your .48 and you"ll drop that lag by about 1000 rpm's and 14 lbs of boost is pretty tame, so work on your tune to get at 18 to 20 lbs it will take off but not with the .63 exhuast housing, or prove me wrong.

Ben

[catapultkid]

Ben,

Brakes are stock up front, and t-bird rears. I have the brackets to put mustang items up front already. The PO bought them and never put them on. It is a "top priority" item. My wife said there where times that the rears where locking up first before a turn, and I know I had to really really put my foot in them for it to do anything at all.

Thanks once again. I checked psi and struts at the beginning of the day but then had my face in the laptop. I remember hot temperatures of tire being around 35 to 37 up front and about the same/maybe a hair less in the rear. We need a test and tune day before I can start dialing that stuff in along with all the other items. 650lbs springs will be a much better start than what I have now, thank you for that. I know I saw over 6 inches of daylight under the car when my wife was driving, and you could see it start to push as soon as it lifted. They are SPAX adjustable rear struts BTW. I can feel the potential in the car, but it isn't there yet by any stretch of the imagination.

Estaban mentioned on one of the other treads that the MBC may be to blame for the crappy lag. I think he has a point, I have a 7psi wastegate, so it doesn't take much of anything to start cracking that thing open. I'm going to start there and then start adding the boost like you mentioned. Shooting for 18psi next with a electronic boost controller.

If the turbo is still posing a issue here is what I have in mind.

Get my .48 exhaust side that I have sitting here, rebuilding it with new bearings, then adding a larger coldside like Ray did and the larger GN housing. They are pretty cheap here on c'list. Then I'll have something not ebay, and should make decent power all around.

[DSPXR4ti]

Ben,

Brakes are stock up front, and t-bird rears. I have the brackets to put mustang items up front already. The PO bought them and never put them on. It is a "top priority" item. My wife said there where times that the rears where locking up first before a turn, and I know I had to really really put my foot in them for it to do anything at all.

Thanks once again. I checked psi and struts at the beginning of the day but then had my face in the laptop. I remember hot temperatures of tire being around 35 to 37 up front and about the same/maybe a hair less in the rear. We need a test and tune day before I can start dialing that stuff in along with all the other items. 650lbs springs will be a much better start than what I have now, thank you for that. I know I saw over 6 inches of daylight under the car when my wife was driving, and you could see it start to push as soon as it lifted. They are SPAX adjustable rear struts BTW. I can feel the potential in the car, but it isn't there yet by any stretch of the imagination.

Estaban mentioned on one of the other treads that the MBC may be to blame for the crappy lag. I think he has a point, I have a 7psi wastegate, so it doesn't take much of anything to start cracking that thing open. I'm going to start there and then start adding the boost like you mentioned. Shooting for 18psi next with a electronic boost controller.

If the turbo is still posing a issue here is what I have in mind.

Get my .48 exhaust side that I have sitting here, rebuilding it with new bearings, then adding a larger coldside like Ray did and the larger GN housing. They are pretty cheap here on c'list. Then I'll have something not ebay, and should make decent power all around.

Thats still to low, 37 to 39 will be a better start with only 1.8 to 2.5 unless you can get -3.0 or more. I run 40 psi and running -2.75 camber, good to great tire wear for A6's (85+ run's)

I would like to hear how you do with that hot side (.63) and if you can get it below 3000 rpms or better.

Ben

Ben

[Esteban]

Do you have an adjustable wga rod? If so, give it a little bit more preload to increase boost. It will help spool time too.

[catapultkid]

Ok

Ordered some parts and here are some pictures (they keep moving so hopefully the link will stay for awhile or I'm going to have to download)

Parts ordered so far:
Scorpio LCAs
Electronic boost control solenoid

How many xr's do you see?



















The other xr

[DSPXR4ti]

Great pic's of your/the XR's,

Ben

[Esteban]

Are the other XR's forum members?

[hEaT]

Always awesome to see a group of XRs dodging cones!

[catapultkid]

It is nice that our club has David as a photographer.

I know Morgan (the white one) is on here from way way back. Not much anymore I don't believe.

Not sure about Greg (the other two tone)

[Esteban]

What are you using to prop your hood open? It opens up really wide! There should be hood stops that prevent it from opening that far back.
Still work on relocating your WB sensor, at least 18" from the turbo. It's way too close that you may get funky readings and burn up the sensor. The heat shielding you have on it isn't going to protect it.

[catapultkid]

I think the hood prop is from a Nissan, my brother lost mine so I took his. It puts it on the bump stops perfectly and has been nice so far.

Your right about the O2, but is low on the list at the moment.

[catapultkid]

Autox next weekend so it is time to get busy. First issue was the tire lifting. The rear struts are single adjustable (rebound only) and where set to max stiff, so as Ben was saying, during a corner the rear loads/compresses and until a straight or a switch in direction the rear strut holds the trailing arm in position. Therefore never letting the front come back down. First step is adjust the struts to full soft and go from there. Heavier springs will be in order soon but I want to see the change with adjustment in struts as is first.

Since the brakes where an issue last time I've been on the hunt for a bigger set. I scored these used mustang calipers w/slider fully dressed for 90 shipped and seem to be in good condition. I already had the David Godfrey conversion bracket here from the previous owner so it was a easy choice as far as an upgrade is concerned and so far cheap. Went to autozone and found some $25 white box rotors that are 11" in diameter (SVT contour) vs the old 9.5" or whatever it was. They are also a little thicker. I think the master cylinder will have to get bigger before it is all said and done to get the prefect feel but this should be a quick fix until then.

Mocked up on one of the spare spindles







Caliper size comparison, much bigger than what is on there now.



Also spend some time adding a electronic boost controller to the mix. Can't use it yet but it is wired in at least. Getting in a 15 psi wastegate in as well soon. We noticed that the 7psi wastegate we have is cracking under moderate to light load and leaking a bunch of the exhaust pasted the turbo meaning more LAG. I did the quick fix of adding a wire to keep the wastegate closed and boost came on about 400-500 rpm sooner with a bunch more torque down low where we need it.



More to come next week hopefully. Been busy doing other things recently.