went to the drag strip last weekend, not so great

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whitelx
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went to the drag strip last weekend, not so great

Post by whitelx » Mon Nov 10, 2008 9:45 pm

I decided to take my XR4Ti to the drag strip this past weekend since my Mustang is down with a main bearing failure. For some reason the car is slow. Not exactly sure what the cause is.

my best pass:

R/T ..... 0.106
60'....... 2.214
330 ..... 6.362
1/8 ..... 9.743
MPH .... 74.75
1000 ... 12.575
1/4 ..... 15.007
MPH .... 93.17

Mods:
2.3L .030 over
8:1 wiseco pistons
Crower 5.5" rods
ARP studs
Boport stage 2.5 oval port head with big valves
Erson turbo slider cam - 218/212 @ .050, .456/.450
ported/gutted intake
ported E6
stock T3 w/ .63 turbine - 20psi
Rapido intercooler
Forge BOV
35lb Tomco injectors
Kirban fuel pressure regulator - 50psi base pressure
255lph Walbro GSL392 inline pump
LA3 computer
Big VAM
cone filter
NGK TR6 plugs gapped @ .025"
MSD blaster TFI coil
MSD plug wires
3" turbo back exhaust
3" Magnaflow cat
3" magnaflow muffler
89 2.3L Mustang T5 trans
stage 3 6-puck clutch
3.64 rear gears

The car weighed 2770 without me in it. The only thing I have done is removed the A/C and removed the spare tire. I haven't had a chance to check the A/F ratio since my JAW was acting up and was sent back for repair. I also want to do a compression test and check the cam timing.
1986 XR4Ti - 294rwhp/315ft-lbs
1992 Mustang 5.0 notch - 434rwhp/445ft-lbs
http://www.youtube.com/user/whitelx

86XR4Ti_John
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Post by 86XR4Ti_John » Mon Nov 10, 2008 10:58 pm

yes that is a bit slow. Especially with all your really dope mods done!

Mine was slower than expected as well. Mine went a really embarrasingly slow 16.8!!

Then mine is VERY close to stock, but I was expecting mid 15's.

What do you have for tires? I couldn't get better than a 2.5 second short time.

PS I am usually one of the fastest cars there, not counting the faster outlaw cars, and this time I was on the other end of the spectrum. Quite humbling...
John

86 Xr, lowered, cossie rear sway bar, wheels, intercooled, big vam, PE superchip.
91 Talon TSi, well modified, 5spd all wheel drive, runs 11's.

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whitelx
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Post by whitelx » Mon Nov 10, 2008 11:05 pm

86XR4Ti_John wrote:yes that is a bit slow. Especially with all your really dope mods done!

Mine was slower than expected as well. Mine went a really embarrasingly slow 16.8!!

Then mine is VERY close to stock, but I was expecting mid 15's.

What do you have for tires? I couldn't get better than a 2.5 second short time.

PS I am usually one of the fastest cars there, not counting the faster outlaw cars, and this time I was on the other end of the spectrum. Quite humbling...
I was running 205/50R16 Kumho ASTs. Nothing special, but almost new. Track was prepped really well since they were running a PSCA event.

I was actually bogging a bit out of the hole. Once it came up on boost it moved out fairly well, but for some reason it's just not running the numbers. I expected at least low 14s out of it. I've seen people running 13s with similar mods. I just don't get it. Sure, it could stand or have a tune and larger injectors, but others are running faster without those items.

I'd love to run a 2-step and some sticky tires, but I don't think the stock differential would last very long. I bet I would see a huge improvement being able to launch with some boost.
1986 XR4Ti - 294rwhp/315ft-lbs
1992 Mustang 5.0 notch - 434rwhp/445ft-lbs
http://www.youtube.com/user/whitelx

86XR4Ti_John
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Post by 86XR4Ti_John » Mon Nov 10, 2008 11:11 pm

I had this problem with the Talon once. I would almost bet on way overfueling it.

I went 1.5 full seconds slower once, when I was first learing to tune. Took out the fuel and immediately went faster by a LOT!! In fact I improved a full 2 seconds once I got it sorted out fully. 15.3-13.3, same setup, just alot leaner.

Not sure if you can pull fuel out with your electronics, but you could at least try to take 3-5 psi out of your regulator and try that.

PS, your tires are WAY more tire than my 205/60/14, BFG radial T/A. :)
John

86 Xr, lowered, cossie rear sway bar, wheels, intercooled, big vam, PE superchip.
91 Talon TSi, well modified, 5spd all wheel drive, runs 11's.

onebad7up
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Post by onebad7up » Mon Nov 10, 2008 11:56 pm

You have similar mods to my Ranger. My best is a 1.9 60 foot at 8.74 in the 1/8th.

Some better 60 foots would have at least got you in the low 9's.

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deathbypsi
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Post by deathbypsi » Tue Nov 11, 2008 10:36 am

That MPH is really weak. There is something off big time. Double check that the cam is setup correct and see where your timing is.

My car with a home ported head and only 16psi ran 103mph.




*off topic* Sell me that Ranger!
Brian R.
86 SVO

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T4EaterJonny
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Post by T4EaterJonny » Wed Nov 12, 2008 4:08 am

Yeah man. 170 hp can get you a 15. 1/4 You should be running high 13s at least. Boost leaks?
2005 SRT4- Stage 3
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Post by whitelx » Wed Nov 12, 2008 4:14 am

T4EaterJonny wrote:Yeah man. 170 hp can get you a 15. 1/4 You should be running high 13s at least. Boost leaks?
Boost gauge is connected at the manifold. It's making a solid 20 psi. All of the connectors are new multi-layer silicone. No leaks in the intercooler.

I'm going to start working on it tomorrow. I've been thinking about picking up a degree wheel kit so I can degree the cam in. That what I know it is installed correctly.

Timing is at 10° initial. I left the spout disconnected on one run by accident. It really didn't like that as it ran a 16.4 @ 83. :?
1986 XR4Ti - 294rwhp/315ft-lbs
1992 Mustang 5.0 notch - 434rwhp/445ft-lbs
http://www.youtube.com/user/whitelx

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Post by EVIL_XR4 » Wed Nov 12, 2008 11:00 am

The MPH seems about right for 15 flat, but you'd be deep in the 14s or better with a quicker 60. It's hard for me to say what you should be running though since i don't know much about how the 2.3T's do for drag racing. I've seen some really fast ones, clear up to a 9 second Mustang, but in a Merkur with the IRS it's tough to say. I have a Mustang mag that has an article about a 2.3t meet that had 2 XR's that showed, both ran in the 12s with similar mods, so you may well have a problem somewhere, but don't count out simple lack of experience if you're new to drag racing.

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Post by Ed Lijewski » Thu Nov 13, 2008 2:11 pm

Don't know about the Kumho ASTs but I've got a set of the same size Kumho Ecstas on one of my two XRs, and a set of Michelin MXV4 Energys on the other; just pushing the one with the Ecstas forward or backward in my garage (withut the engine of course) requires much more effort than than it does with the other XR with the Michelins. The Michelins seem to have minimal rolling resistance; the Kumho Ecstas a LOT. I wouldn't haave bought the Kumhos had I known that.

YMMV 8)
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Post by DPDISXR4Ti » Thu Nov 13, 2008 2:32 pm

Ed Lijewski wrote:The Michelins seem to have minimal rolling resistance; the Kumho Ecstas a LOT. I wouldn't haave bought the Kumhos had I known that.
Perhaps what you should do is get four spare wheels - get them from a Contour so the rubber won't be rotted. Put 60 PSI in them and you'll definately reduce your rolling resistance. Probably get better fuel mileage as well!
Brad

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Post by Ed Lijewski » Thu Nov 13, 2008 2:34 pm

Spew snidery and faux superiority all you want (it's in your genes)--rolling resistance is real, and the example I gave is a real world way of tangibly demonstrating it.

YMMV 8)
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Post by DPDISXR4Ti » Thu Nov 13, 2008 2:40 pm

Ed Lijewski wrote:...and the example I gave is a real world way of tangibly demonstrating it.
Using two different vehicles as your supposed test constant? And using the finely calibrated instrument of your hand pushing the vehicle? Close enough for gov't work I guess! :P
Brad

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Post by BeefFajitas » Thu Nov 13, 2008 4:22 pm

Or maybe that's a good test for a frozen caliper.....
-Nate
'85 Merk. Back together. Only thing stock is the head and block.

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Post by EVIL_XR4 » Thu Nov 13, 2008 5:57 pm

The best 60 foot i've ever got on street tires was with Kumho Ecstas on an '89 Mustang GT with a 347 in it. That was a 1.9 60, which is what i'm now getting on my drag radials. I'm not saying they're fantasitc or that they don't have rolling resistance, but they're pretty decent for a budget tire. I bought the AST's (think that's what they are) for my XR's ARE's if i ever get'em finished.

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