El Mirage vs Bonneville speed comparison

[Eddieschopshop]

Okay so I am curious to see what teams speeds are that run both venues.  What do you see 10% faster,  15%, 20% etc?

[Stan Back]

We're about 8% faster at Bonneville when we held both records in our class.   But that's a Street Roadster.  Steve Batchelor's C/CFALT was 14% faster when (I think) he held both records.  I'd guess that the Altered keeps slipping along.

[Eddieschopshop]

Thanks Stan,  thats exactly the type of info I was looking for.  Its hard to tell just by looking at records since they are set by different cars etc,  or if it is the same car the settup may have changed between records.   In looking at the book some of the records can be as much as 30% different

[Stainless1]

And different between long and short course cars...
You will be fine... have fun 

[Stan Back]

The four I quoted were long course cars.

(And with the very same engine.)

[SPARKY]

2008 
AA/GL  223. at el M
AA/GL  306 at b'vill one month earlier

[Eddieschopshop]

Wow that's a big difference.  Were you running the same gear ratio at elmo?  I think I am probably one of the few that doesn't change gear ratio between the two.

[Speed Limit 1000]

A long course car likes more room to run

[jimmy six]

My difference has been 10 MPH. Naturally aspirated gasoline vintage engine since 1975.

[jl222]

 
 Going back to 1990 El Mirage the 222 Camaro set a record at 229mph 29 lbs boost. Bville 1991,  same tune up but higher gears 271 12lbs boost. By upping gear ratio and not spinning blowers faster they didn't get enough rpms to make enough boost. Bville 1994 lowered gearing upped  blower gearing. 288 with 279 exit speed 33lbs boost.

 El mirage 2009 new motor can't hook up '' marbles '' Bville 2009 or 10, 294 in 1st mile but blew.

             JL222 

[SPARKY]

Yes I ran the same gears-

if had a good track and geared for max  at El M  my guess 235--maybe 240

At b'ville I am doing 180-200 at the 1   
230-270 at the 2 /1/4  all depends on  what "going on"
299-309 out the back

[Eddieschopshop]

Thanks for the info. Always like getting data to chew on.  I am really surprised going up in that much boost with didn't result in a bigger number. With te lower gear were you out of rpm?  Thanks Sparky if I can match your numbers I would be thrilled.  I think the roadster aero may hurt me more though..

[jl222]

Thanks for the info. Always like getting data to chew on.  I am really surprised going up in that much boost with didn't result in a bigger number. With te lower gear were you out of rpm?  Thanks Sparky if I can match your numbers I would be thrilled.  I think the roadster aero may hurt me more though..
[/quote

  To me anyhow, 1.85 is higher gearing than 2.35  just like a 3.55 rear gear ratio is higher than 4.11.
 A bit confusing because the numbers are the opposite

  1991 we were way over geared 1.85 -1 and only a 2 speed trans. Sometimes listening to the '' experts?''
doesn't pay off   Centrifugal blowers need to spin about 8 times engine speed or more to make the boost
we want. With the low gearing, engine rpm wasn't high enough to make enough boost.

 1994-288mph same 2 speed trans with overdrive and lower gears 2.35  a 279 exit speed because the overdrive trans clutch slipped and engine went to 8300 rpm caught a valve and blew one of the blowers off right before last timing light coasting thru exit speed traps. A course patrol asked me how fast I thought I was going before I blew I said about 313. Hey this is a Camaro door slammer what do you expect?

  Note to Electromotive users. Their rev limiter was based on retarding the engine which limit was set at 7500 rpm
well engine still liked 18 deg advance. Can't remember 21 yrs back but think I had set retard at max. Maybe newer units have changed.
 

              JL222
 

[turborick]

Good Streamlines typically have a much bigger difference. we have seen about 100mph difference on our streamliner.

[Stan Back]

Agreed.

Street Roadsters not so much.