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View Full Version : Anyone dyno their bonestock/slightly modded XR-7 or SC??



Wagonman88
11-12-2009, 01:47 PM
I found this (http://www.musclemustangfastfords.com/tech/mmfp_0707_1990_thunderbird_super_coupe/index.html) link to what a stock 1990 SC puts down and what a few mods will do. I was just wondering if the 89's made any more power and if anyone has some numbers with say headers and a cam also installed.



Jeremy

P.S. I realize this isn't really the best section to post this in but I figured more people that actually race their car would know what they put down with mods than the typical guy.

XR7 Dave
11-12-2009, 10:53 PM
Been done many times. Typically bone stock will make about 190rwhp (5spd). The 89's did not make any more power than any other year.

I made 255 with stock blower and ported heads/cam. A lot of other people have done the same or slightly better.

I made 285 with ported blower and cam. Blower improvements always net the biggest gains. A good cam is a big plus too.

Headers won't do anything.

Mike8675309
11-12-2009, 11:55 PM
Here is a chart from my first SC. A 1989 car with a 5% blower pulley and K&N panel filter, otherwise stock, and with spark plugs and wires that were probably 4 years old.

You can see how much heat soak of the stock I/C affected the second run. The zaggies in the graph is caused by the engine pulling timing. Likely the knock sensor.

http://www.frontiernet.net/~miketoni/images/tbird/horsepowergraph.jpg

neverfastenough
11-13-2009, 01:35 AM
I made 203 270 with underdrives and exhaust on a AOD sc

Wagonman88
11-13-2009, 03:48 AM
I'm aiming for 350+ eventually. The plan is a 4.2 short block with possibly an MPx case and a good set of heads and cam. That is further down the road however. If I can hit 350 on the stock bottom end I would be thrilled though!!



Jeremy

XR7 Dave
11-13-2009, 09:06 AM
Here is a chart from my first SC. A 1989 car with a 5% blower pulley and K&N panel filter, otherwise stock, and with spark plugs and wires that were probably 4 years old.

You can see how much heat soak of the stock I/C affected the second run. The zaggies in the graph is caused by the engine pulling timing. Likely the knock sensor.


Actually Mike, that isn't caused from anything pulling timing. When timing is pulled the result is a relatively smooth loss of power. It would be more likely that the jaggedness is caused by a cylinder or two not firing at full capacity. Too much timing (detonation), lean AFR, rich AFR, and general ignition issues will cause a jagged dyno curve.

Wagonman88
11-13-2009, 11:43 AM
As will an improper spark setting on the dyno itself, or interference elsewhere on the pickup. I've seen misfires on dynos before (seen a lot of RX-7's dyno and they are notorious for this) and usually it's only a few blips, not across the entire curve though.



Jeremy

rbrown
11-13-2009, 02:21 PM
http://www.bunlimited.com/misc/dyno1sm.jpg

All stock 160,000 miles
187 was with AC on
192 AC off
209 AC off and swap out 75mm TB


And yes I know the Fuel looks awful.

Wagonman88
11-13-2009, 07:14 PM
What happened there? I doubt a TB would have richened it that much!! 17hp with a TB is pretty damn good... It would be more if it wasn't so rich too.



Jeremy

P.S. Auto or 5 speed?

XR7 Dave
11-13-2009, 07:57 PM
If you read/believe what was posted above at face value then you are on the start to a long road of disappointment.

The above post shows a stock tune which programs the car to run very rich at higher rpms, in fact his car is running even a little richer than stock at the 180-190hp level.

The above post also shows a car tuned to run at about 13:1 AFR which is way too lean but it made a great HP number for the dyno.

In no way should that be interpreted to mean that a 75MM TB nets 17rwhp. On a stock or nearly stock SC the 75MM TB will net you absolutely 0 HP gain. Any gains shown in that dyno are a direct result of tuning.

rbrown
11-13-2009, 11:19 PM
But there was no tune.
The only thing touched was new head gaskets at that point.

We discussed the fact it was leaning out for some odd reason. Have not looked further into that.

5 speed.

XR7 Dave
11-14-2009, 12:57 AM
But there was no tune.
The only thing touched was new head gaskets at that point.

We discussed the fact it was leaning out for some odd reason. Have not looked further into that.

5 speed.

The other reason why it might have done that is if the engine was cold when the 3rd run was made because, oddly enough, the EEC commands a leaner AFR when cold, the knock sensor is inactive, and of course ACT's would not have given cause for timing to be pulled. Guarantee you take the car back warm and it will turn up the same #'s that it initially did. :)

Oh, and now that I realize that the car is a 94/5, that AFR (the one that falls off the scale rich) is dead nuts by the stock tune.

Super Duper Cou
11-14-2009, 12:58 AM
My 1993 Super Coupe with an aod transmission made 190rwhp and 280ft-lbs of torque with only a bigger mass air flow and a K&N air filter. It also made 194rwhp and 281ft-lbs of torque with a 5% overdrive supercharger pulley. Then I added 2 1/2 inch dual exhaust and made 227rwhp and 330ft-lbs of torque. I have a custom built raised supercharger top and a custom front mount intercooler on it now but I haven't taken it back to the dyno.

rbrown
11-14-2009, 01:36 AM
Well you have a tune on it now. But you tempt to put it back stock and see.

The first run (AC on) was 30 minutes or so after getting there and them strapping on machine.
Run 2 (AC off) was too soon after run 1. Burped water it got really warm.
Run 3 was immediately after putting throttle body on after run 2. However long that would take. 45 minutes max. Had my kids with me so sit around and wait for it to cool was not in the equation.

One other thing that was weird was the AFR was going rich was only with the stock throttle body. This was another point we scratched our heads over since the BBK "cleaned" it up. Maybe it did so good because it was a throttle body off a Mustang.


Rodney

rbrown
11-14-2009, 01:37 AM
And I am kidding about the Mustang throttle body. <grin>

fturner
11-14-2009, 09:09 AM
A nasty vacuum leak will also lean everything out.... a leak that only rears it ugly head the more air demand there is, and that started after the throttle body change.

Things just don't magically change with a throttle body change, since it does nothing to change anything to a tune, and if it did allow more "metered" air in (highly doubtful since the car is stock and you where no where close to maxing out the stock TB) the AFR would have stayed the same as the previous runs.

Also, I think it irresponsible for the dyno shop to keep going with a pull to the end with AFR's like that. If I see AFR's going into the 12's on these cars I immediately let off. You where lucky, darn lucky the car went into the 13's like that, because if it had stayed around 12.6 or so.......

Fraser

XR7 Dave
11-14-2009, 02:20 PM
Run 2 (AC off) was too soon after run 1. Burped water it got really warm.
Run 3 was immediately after putting throttle body on after run 2. However long that would take. 45 minutes max. Had my kids with me so sit around and wait for it to cool was not in the equation.


Any time the car is started it runs in cold startup mode for a prescribed amount of time. If the car was started and run immediately then most likely it was still on the cold start table during the run.

rzibilske77
11-14-2009, 03:02 PM
A nasty vacuum leak will also lean everything out.... a leak that only rears it ugly head the more air demand there is, and that started after the throttle body change.

Things just don't magically change with a throttle body change, since it does nothing to change anything to a tune, and if it did allow more "metered" air in (highly doubtful since the car is stock and you where no where close to maxing out the stock TB) the AFR would have stayed the same as the previous runs.

Also, I think it irresponsible for the dyno shop to keep going with a pull to the end with AFR's like that. If I see AFR's going into the 12's on these cars I immediately let off. You where lucky, darn lucky the car went into the 13's like that, because if it had stayed around 12.6 or so.......

Fraser

It was strickly performance...........ive heard waaaaaay to many horror stories about them.

rbrown
11-14-2009, 10:04 PM
It was strickly performance...........ive heard waaaaaay to many horror stories about them.

I have heard stories about every shop here in town.

Wagonman88
11-16-2009, 12:06 AM
I was looking at the wrong line for the fuel. My bad.

That's crazy that Ford richens them that much over 4K... I'm thinking that the QH is going to be a very nice piece to my setup, coupled with a solid tune of course.



Jeremy