XR Chassis mods

XR4Ti / Sierra / Sierra Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
Merkur Club web site
User avatar
Ray
Level 7
Level 7
Posts: 4332
Joined: Sun Oct 24, 2004 10:40 am
Location: CT, USA

Re: XR Chassis mods

Post by Ray »

Wow, that is insane power with stock head. Nice :)
-Ray
1985 Ford F150 - Tow Missile
1985 Merkur XR4Ti -#141 CP "Miss Daisy"
2005 Subaru LGT
http://www.cartct.com
User avatar
merkurdriver
Level 8
Posts: 6160
Joined: Tue Jan 21, 2003 4:29 pm
Location: Northeast Ohio
Contact:

Re: XR Chassis mods

Post by merkurdriver »

287HP with stock head, stock cam and stock turbo! :notworthy :cheers Wow, thats really impressive.
User avatar
pyropete125
Level 7
Level 7
Posts: 1311
Joined: Wed Jan 07, 2004 2:51 am
Location: west haven, CT

Re: XR Chassis mods

Post by pyropete125 »

awesome car for sure!

engine dyno or chassis? mustang or dynojet?

stock ports and valves?

stock or ? bottom end?

287hp seems awfully high for what little has been done. what class are you going for?? GTS?

Your IC is working good! I have a log from 21 psi on a 90* day with a cut down mack truck IC I made:

http://img.villagephotos.com/p/2002-10/ ... 28--04.jpg

Pete
89 xr4ti, LOTS'O'MODS. PICS OF MY XR, FOLVO STUFF, AND...
youngfg
Level 2
Level 2
Posts: 198
Joined: Mon Dec 06, 2004 11:53 am
Location: Owensboro, KY

Re: XR Chassis mods

Post by youngfg »

I dynoed the car on a load bearing Superflow Chassis dyno.
My motor came out of the original XR that I bought for $150.00, I have not had it open, I can only imagine that it's totally stock. It probably has about 200k miles on it.

I will run NASA time trials in it, in Super Unlimited class.

It ran OK at the track. My rear shocks and springs are too stiff, the car is really loose. Other than a few little issues the first time out went great.
My biggest fabrication item left is making a rear wing for the car. I think I am going to make a mold off my fiberglass RS500 wing so I can make a CF one. I will also make a regular airfoil style wing for it.

Here is the MSQ file in the car right now, I am running MS1 Extra, 029Y firmware.
MSQ file

Pic from the track.
Image
Gene
User avatar
John Brennan
Level 8
Posts: 11630
Joined: Wed Jun 18, 2003 4:19 pm
Location: Scottsdale, AZ "Summer Is Coming"

Re: XR Chassis mods

Post by John Brennan »

"We're not worthy! We're not worthy!" :notworthy

Beautiful car... :headbang
This is my car, and these are my people!
1989 XR4Ti 5-Speed
2001 BMW Z3 3.0 5-Speed
2015 Fiesta ST 6-Speed
2015 Edge 3.5 V6 Auto/Paddles
thebronze
Level 7
Level 7
Posts: 1031
Joined: Sun Aug 03, 2008 1:27 am
Location: Delta/Surrey, BC, Canada

Re: XR Chassis mods

Post by thebronze »

John Brennan wrote:"We're not worthy! We're not worthy!" :notworthy

Beautiful car... :headbang

Maybe Your not....
Kevin
Image
88 VW Cabby...........Starbucks poses by ME
Life's tough. It's even tougher if you're stupid.
-John Wayne
User avatar
John Brennan
Level 8
Posts: 11630
Joined: Wed Jun 18, 2003 4:19 pm
Location: Scottsdale, AZ "Summer Is Coming"

Re: XR Chassis mods

Post by John Brennan »

I figure if I were, I'd have it, or something like it... "but I have promises to keep," and so forth. I chose to have a large family, and don't regret the decision... even if it means I must sometimes just watch and cheer others' efforts.
This is my car, and these are my people!
1989 XR4Ti 5-Speed
2001 BMW Z3 3.0 5-Speed
2015 Fiesta ST 6-Speed
2015 Edge 3.5 V6 Auto/Paddles
User avatar
pyropete125
Level 7
Level 7
Posts: 1311
Joined: Wed Jan 07, 2004 2:51 am
Location: west haven, CT

Re: XR Chassis mods

Post by pyropete125 »

what tire/rim size and compounds are you running?

the care is awesome! it does need something badass in the back though for a wing. a large airfoil is probably the ticket.

with more downforce in the rear will that make your current shocks/springs ok?
89 xr4ti, LOTS'O'MODS. PICS OF MY XR, FOLVO STUFF, AND...
youngfg
Level 2
Level 2
Posts: 198
Joined: Mon Dec 06, 2004 11:53 am
Location: Owensboro, KY

Re: XR Chassis mods

Post by youngfg »

For wheels right now I have 17X10.5 front and rear.
I have some old 335/35/17 Kumho V710's on the car now.
They are a little too wide for the 10.5" rim, I will get some new 315's when I ready to run the car some more.

I will probably get some custom 17X12 rims so I can run the 335's

The car is too loose in low speed corners where a wing wouldn't help, and it's crazy loose on the high speed corners.
Generally cars have more trouble with understeer as the slower the corner becomes.
The perfect setup is to have the spring/shocks make the car handle neutral or slightly loose in the low speed corners, then have enough rear downforce to keep the car stable/understeer in the high speed corners.

I will probably run a wing like this car has.
Image
Image
Gene
User avatar
Loc
Level 1
Level 1
Posts: 58
Joined: Thu Jul 26, 2012 11:20 pm
Location: South East Idaho
Contact:

Re: XR Chassis mods

Post by Loc »

I cryed . Wet my pants. Turned Green with envy and then just sat here in shock as i went through this !!! :notworthy :headbang Gene= Merkur Idol.
Dave.
I Ask, Merkur-To V8 or not to V8? Answer, BOTH !!!!!
https://www.facebook.com/media/set/?set ... 389&type=1
User avatar
Raze
Level 3
Level 3
Posts: 248
Joined: Sun Dec 03, 2006 7:59 pm
Location: Atlanta, GA

Re: XR Chassis mods

Post by Raze »

Did I read your MSQ file right that you're running 15.8-14.3 AFR Target? Your spark looks normal. If you're running near stoich @ load that's impressive...
HY35w, FMIC & BOV, 3" exhaust, 75#/hr, 255lph, MegaSquirt-I V3 w/3bar, T5, 4-point roll bar, rear strut brace, gutted, lexan windows and sunroof, Odyssey PC680, Koni + Ground Control (7" 250#/in) front, KYB (8.5" 600#/in) rear, TC rear brakes
youngfg
Level 2
Level 2
Posts: 198
Joined: Mon Dec 06, 2004 11:53 am
Location: Owensboro, KY

Re: XR Chassis mods

Post by youngfg »

I don't run closed loop, so you can ignore the AFR targets.
Gene
User avatar
Raze
Level 3
Level 3
Posts: 248
Joined: Sun Dec 03, 2006 7:59 pm
Location: Atlanta, GA

Re: XR Chassis mods

Post by Raze »

Us too, that's why I asked :) that's a crazy graph, though your remark about the IAT being 99 deg would be a major factor, that's ridiculously cool. It looks like you're running out of fuel up top though as your AFR shoots up the last 500rpm. What fuel pump/injectors/fuel pressure regulator you running? I ask because we're running a stock 180k+ engine with 75#/hr injectors and a high pressure 255lph pump on the stock regulator and have no problem controlling AFR right out to 6500 rpm...
HY35w, FMIC & BOV, 3" exhaust, 75#/hr, 255lph, MegaSquirt-I V3 w/3bar, T5, 4-point roll bar, rear strut brace, gutted, lexan windows and sunroof, Odyssey PC680, Koni + Ground Control (7" 250#/in) front, KYB (8.5" 600#/in) rear, TC rear brakes
youngfg
Level 2
Level 2
Posts: 198
Joined: Mon Dec 06, 2004 11:53 am
Location: Owensboro, KY

Re: XR Chassis mods

Post by youngfg »

Yes it's running out of fuel.
I am running a Bosch external pump, stock rails, regulator, and injectors.
I plan on getting some bigger injectors, I just haven't had time to work on the car at all.
Gene
Post Reply