Miss T did a 10

[brad24]

On her second trip to the wednesday night street meet my XT started running high 10's
Can you fella's have a look at these two quickest time slips & tell me what you think.
The night was pretty warm & humid, with thunderstorms all round the track for most of the night.
Will the car run quicker in less humid weather?
We ran 8 passes, the first 2@ 11.0's, with another 5 passes 10.9's

[dieseltrain79]

Pretty good conditions for NA cars .

Going off the 60' and mph , your at its limit . You might squeeze a 10.8 but that's about it .

Congrats

[brad24]

Originally Posted by dieseltrain79

Pretty good conditions for NA cars .

Going off the 60' and mph , your at its limit . You might squeeze a 10.8 but that's about it .

Congrats

Cheers mate

[Windsor]

Originally Posted by dieseltrain79

Pretty good conditions for NA cars .

Going off the 60' and mph , your at its limit . You might squeeze a 10.8 but that's about it .

Congrats

Gents I agree. You are showing about 540hp.

Cheers,
Steve.B

[brad24]

Originally Posted by Windsor

Gents I agree. You are showing about 540hp.

Cheers,
Steve.B

On the engine dyno the egine showed 602Hp
We used Chaisty's dyno which is known for being stingy with its readings.
The car showed 438rwhp on a chassis dyno.

Any suggestions as to where the Hp would of gone to from engine dyno to drag strip if its only showing 540hp based on its mph & weight?

[gcg2503]

Brad I got 470hp on the engine dyno and only 295rwhp on the chassis dyno - hot weater is to blame for mine as is the power sapping FMX

Great times for second outing though!

[brad24]

Originally Posted by gcg2503

Brad I got 470hp on the engine dyno and only 295rwhp on the chassis dyno - hot weater is to blame for mine as is the power sapping FMX

Great times for second outing though!

cheers mate, I had a ball

Wow thats like 37% power loss

I appreciate that chassis dyno's have a lot of variables, Id just like to know where my power has gone from engine dyno the drag strip

[dieseltrain79]

Has the carby been tuned on the dyno or at the track ? Jetting ?

I've known many engine dyno'd motors that need refuelling after they been on the track . The engine loads differently when pushing the weight . That can change mph a few notches .

Best way to read the plug after a run , remove it in the deep end . Check plug & adjust jets

[Windsor]

Originally Posted by brad24

On the engine dyno the egine showed 602Hp
We used Chaisty's dyno which is known for being stingy with its readings.
The car showed 438rwhp on a chassis dyno.

Any suggestions as to where the Hp would of gone to from engine dyno to drag strip if its only showing 540hp based on its mph & weight?

Brad I would be looking at the correction factors on the engine dyno. If this dyno is noted for being "stingy", your mph should be at least 130. You have enough convertor and rear gear to achieve this if the power is there.

Cheers,
Steve.B

[brad24]

Originally Posted by dieseltrain79

Has the carby been tuned on the dyno or at the track ? Jetting ?

I've known many engine dyno'd motors that need refuelling after they been on the track . The engine loads differently when pushing the weight . That can change mph a few notches .

Best way to read the plug after a run , remove it in the deep end . Check plug & adjust jets

The car hasnt been tuned at the track at all, only on the engine dyno
Cheers

[Windsor]

Originally Posted by brad24

The car hasnt been tuned at the track at all, only on the engine dyno
Cheers

Brad didn't you spend some time on the rear wheel dyno with Simon tuning? Pipes on off etc.. The gain was 88rwhp from memory?

Cheers,
Steve.B

[XT302]

Brad,
Bit hard as not a lot of passes under your belt with the combo but does it feel strong through the whole run? In videos you posted it sounds strong.

Maybe try small single adjustments eg jets or timing and see what affect if any it has?

As for dynos stingy/happy they are good to use as a tuning tool, as you have previously stated stick to one to guage improvements etc

Personally I think don't get stuck on chasing the et/mph the engine dyno showed cause that may just cause unnecessary heartache, if you have built it to run a specific number then by all means chase away, otherwise as it sits its fast and can easily sneak into a bracket already and run consistently?

Cheers

[greencapri408]

Originally Posted by Windsor

Brad didn't you spend some time on the rear wheel dyno with Simon tuning? Pipes on off etc.. The gain was 88rwhp from memory?

Cheers,
Steve.B

There was no real tuning done we just tried a few things
Pipes bigger carb etc
Soverign built brads carb i wasn't touching it
A change of 6 mph shows around a 75 hp gain at the engine
@600 engine hp brads should run 126/127 and 10.60s
I'd like to see a 5k converter i'n it
When i ran mine i had a 4800
And it went a best of 129.5
I made 597 hp on an apparent conservative dyno
But at that mph it's showing nearly 40hp more
If we forget that pass and go off the run i have on video of it running 128 it still shows a gain of about 30hp over what it dyno d at

[greencapri408]

And pipes off was tail pipes off not dropped at the collector

[brad24]

Originally Posted by greencapri408

There was no real tuning done we just tried a few things
Pipes bigger carb etc
Soverign built brads carb i wasn't touching it
A change of 6 mph shows around a 75 hp gain at the engine
@600 engine hp brads should run 126/127 and 10.60s
I'd like to see a 5k converter i'n it
When i ran mine i had a 4800
And it went a best of 129.5
I made 597 hp on an apparent conservative dyno
But at that mph it's showing nearly 40hp more
If we forget that pass and go off the run i have on video of it running 128 it still shows a gain of about 30hp over what it dyno d at

Cheers Simon

[prasac]

dyno's have a correction factor feature which will adjust the power to show as if the engine was running in perfect temp (19C) air pressure etc etc. power could be actually as much as 10% less.

a mate had dyno sheet for his 302W Cortina, it showed like 520hp (3100lbs) right at the bottom of the dyno sheet it said, power was within +/- 10% that is way too much to be off.

[brad24]

Originally Posted by Windsor

Brad didn't you spend some time on the rear wheel dyno with Simon tuning? Pipes on off etc.. The gain was 88rwhp from memory?

Cheers,
Steve.B

Yeah Steve we found 88rwhp on the chassis dyno

8HP by taking the shaker & 9"x2" air cleaner off & running no air cleaner
We then discovered I didnt have the carb cable linkage set up right. It wasnty allowing full throttle. this was worth 58rwhp once we corrected it.
4HP by taking the 2.5" tail pipes off, I thought this would of been a bigger gain.
4HP with Andrews 950 quickfuel carb off his 427
3HP with Andrew's carb & 2" super sucker carb spacer
then we put my carb back on with the 9"x5" air cleaner & gained 10HP

The car went from 350rwhp to 438 rwhp

As Simon says we didnt do any carb or ignition tuning

Im confident that the 602Hp we saw on the engine dyno is accurate, or close at worst.
I think that 600 odd HP out of a 393 clevo, solid roller cam, CHI 208 heads etc
is about right.
The car should be showing more MPH on the track if this is true.

Any ideas as to where the power has gone from engine dyno to being in the car?

[prasac]

as dieseltrain79 said some cars tend to perform differently on the track compared to dyno. do u have any datalogging or AFR meter etc? gearbox/converter feels alright?

you need to track tune, make a change every pass and see how it responds.

the brother would track tune the Capri every time it went out, i remember one night jetting changes etc netted as much as 4/10's and 5mph difference. would just check the plugs in the deep end and adjust from there.

[brad24]

Originally Posted by prasac

as dieseltrain79 said some cars tend to perform differently on the track compared to dyno. do u have any datalogging or AFR meter etc? gearbox/converter feels alright?

you need to track tune, make a change every pass and see how it responds.

the brother would track tune the Capri every time it went out, i remember one night jetting changes etc netted as much as 4/10's and 5mph difference. would just check the plugs in the deep end and adjust from there.

I forgot to add that the day the engine was run in & dyno'd was stinking hot mid Janruary, inside the dyno was like a sauna

I dont have any data logging or AFR meter
Can you suggest a reasonable quality AFR meter?
Ive done a grand total of 12 passes in this (or any car) at the drags (Ive done a fair bit more than that on a bike) but the trans & converter feel OK to me. Trans is a dynamic racing C4 from the US & an allfast converter

Im going to try a different exhaust system at the track, & as you say make some jetting changes after reading the plugs at the end of the track

Possibly upgrade the fuel pump as well

This is one of the passes on the night
http://s567.photobucket.com/albums/s...t=YeahBaby.mp4

[BOTTLEDUP]

Vehicle weight, aerodynamics, converter etc I'm sure all have a bearing.

I know that a similar combo (383ci with ported 185 3Vs bigger comp) which made 610hp on the same dyno ran 10.46@128mph in an XE sedan. That was with 4.11s in the 9" and a 5500 stall. Race weight I'm not so sure about but the car was caged.

[Giant]

The air quality is always changing at the track adjusting fuel and timing can make the most of what is available at that given time. The density altitude is what you want to pay attention to its showing the track effectively went from 430 odd meters above sea level to 413 above sea level by the second slip.

Dyno testing fails to create the same engine load as a standing start also the initial fuel demand is often higher at the track and fuel surge can play a part depending on setup.

[prasac]

the good cool weather/air at the track, it may have been running a little lean. just change one thing at a time and see how u go. change too many things at once and it's hard to know what helped.

http://www.bmotorsports.com/shop/pro...roducts_id/357 under $300 delivered to your door.

[brad24]

The time before whem we went to the track the desity was showing 25ft above sea level

[prasac]

it's also a new combo, so don't stress out too much. you have to get yourself adjusted to the car, once you get to know the car/engine combo you will pick up on things. there is alot of different things you can try, have you tried shifting at different points? you need to look at power thru the whole rev range.

[brad24]

Originally Posted by prasac

it's also a new combo, so don't stress out too much. you have to get yourself adjusted to the car, once you get to know the car/engine combo you will pick up on things. there is alot of different things you can try, have you tried shifting at different points? you need to look at power thru the whole rev range.

The main thing for me is Im havin a ball, driving my street car to the track, doing some runs, then driving it home

I havnt tried different shift points
The engine made max power at 6800rpm & Ive been shifting at 7200

Thanks for the input fella's

[prasac]

Originally Posted by brad24

The main thing for me is Im havin a ball, driving my street car to the track, doing some runs, then driving it home

I havnt tried different shift points
The engine made max power at 6800rpm & Ive been shifting at 7200

Thanks for the input fella's

that's it, well said. you're having fun plus u got a 10-sec street car to boot, what more can u want lol

[Windsor]

Originally Posted by greencapri408

There was no real tuning done we just tried a few things
Pipes bigger carb etc
Soverign built brads carb i wasn't touching it
A change of 6 mph shows around a 75 hp gain at the engine
@600 engine hp brads should run 126/127 and 10.60s
I'd like to see a 5k converter i'n it
When i ran mine i had a 4800
And it went a best of 129.5
I made 597 hp on an apparent conservative dyno
But at that mph it's showing nearly 40hp more
If we forget that pass and go off the run i have on video of it running 128 it still shows a gain of about 30hp over what it dyno d at

Simon in my opinion your mph looks spot on for the dyno hp your engine is showing. Unless Brad's convertor is completely out in left field it is not going to gain mph with a convertor with 800rpm more stall (with his good 60' times)
Seeming this conversation is about street vehicles i will give you 2 examples of similar weight cars.

Rhino XYGT 393 cubes 575 engine horsepower 455rwhp 4 speed 3.9 gears pump fuel 129.66mph

XTGT 363 cubes 430rwhp (on the same dyno as the Rhino) 3.9 gears C4 3600 stall pump fuel 127.98 mph

Neither of these cars make 600hp but you are making 640hp to run similar mph & Brad's is much slower with more hp? Not sure what you gents are using for calculators but track mph is the only accurate one. I have no explanation as to why you gents feel such high stall convertors are needed in your street cars with 393 and 427 cubes? Brad's XT is a well setup car with all the good gear so I cannot see any gains there.

Cheers,
Steve.B

[Windsor]

Originally Posted by BOTTLEDUP

Vehicle weight, aerodynamics, converter etc I'm sure all have a bearing.

I know that a similar combo (383ci with ported 185 3Vs bigger comp) which made 610hp on the same dyno ran 10.46@128mph in an XE sedan. That was with 4.11s in the 9" and a 5500 stall. Race weight I'm not so sure about but the car was caged.

Is the XE running race fuel and a transbrake?

Cheers,
Steve.B

[Windsor]

Originally Posted by brad24

Im confident that the 602Hp we saw on the engine dyno is accurate, or close at worst.
I think that 600 odd HP out of a 393 clevo, solid roller cam, CHI 208 heads etc
is about right.
The car should be showing more MPH on the track if this is true.

Any ideas as to where the power has gone from engine dyno to being in the car?

Brad the only thing i can suggest is if there are no issues with your car eg. fuel, ignition, gearbox etc., I would not be trusting the engine dyno.

Cheers,
Steve.B

[XT302]

Originally Posted by brad24

The main thing for me is Im havin a ball, driving my street car to the track, doing some runs, then driving it home

I havnt tried different shift points
The engine made max power at 6800rpm & Ive been shifting at 7200

Thanks for the input fella's

Brad,

Any idea what it is crossing the line at?

What is the rolling diameter of the rear tyres?

Cheers