Throttle feel on a SPF

Eric Johnson · 25th December 2006, 07:31 PM

Question for SPF owners that have taken delivery: How is the throttle feel / response on your car? When I test drove Dynamic Motorsport's car it had a rather stiff feel with a different modulation that I would have expected.They said they were still experimenting with it and had installed a hydraulic throttle assy.To me the action could be much improved.Any thoughts?

Eric Johnson

JERRYD · 25th December 2006, 08:06 PM

My car was completed by Dennis Oltoff and I find the throttle a little stiff however this is not a bad thing in this car. My car need's exact throttle inputs and that can be difficult with a soft throttle.
Jerry d spfgt40p2124

Mark Worthington · 25th December 2006, 08:15 PM

Hydraulic throttle?

Eric Johnson · 25th December 2006, 08:24 PM

Yes,according to Dean at Dynamic.I thought it unusual also.It wasn't so much the stiffness ,but the modulation that concerned me.I would like to keep it simple.I've spent enough time adjusting and bleeding hydraulic clutches over the years.(Beck 550 spyder)

Eric

chuck smith · 25th December 2006, 09:44 PM

I would think a simple cable like my CAV would be the way to go. It works

Mike Christian · 26th December 2006, 01:34 AM

Hey Eric,

I have a Beck 550 also - S/N 191 that I built in 1989. Did you build yours or as it a roller?

Mike

Eric Johnson · 26th December 2006, 02:31 PM

Mike,
My Spyder is s/n 113 built as a kit in 1986.It's an Upland,Ca. Beck.I'm the second owner and have really enjoyed the car.It has a 2016cc type 1 motor running 45 dellortos driving a Transform transaxle with higher first and second gear ratios.

I am thinking of selling the car,but everytime I drive it I change my mind.It's a fun car as you know.

I remember your posts from the Spyderclub.Good hearing from you.I Hope you get your car soon.I have to admire your patience!

Eric Johnson

1986 Beck 550 spyder
1967 427 Sting Ray
1986 BMW K100 RT
1997 Moto guzzi 1100i sport

Mike Christian · 26th December 2006, 03:12 PM

Thanks Eric...now I know somewhat how those folks feel that order a Vintage Spyder and wait 2-3 years for delivery.

I can't part with my spyder either...I think it fits in well - between the motorcycle and the bigger engined rides.

Regards,
Mike

Eric Johnson · 27th December 2006, 07:09 PM

Mike,
Thank goodness this website hasn't been poisoned by the"Mine is better that yours"mentality that spyderclub.com (porsche 550 replica site ) shows from time to time.Beck and Vintage spyders are both great cars- the Beck a more faithful repro but the Vintage undeniably a great execution(and maybe a improved chassis of the original).

Eric

Mike Christian · 27th December 2006, 07:36 PM

I agree Eric, it's all good.

Peter D · 28th December 2006, 06:49 AM

I had a similar "hard pedal" on my DRB - I changed the cheap cable to an expensive one & smoothed out some of the bends, & I now have about 1/2 the pedal pressure to open the throttles (with no other changes to return springs, etc).

My setup is almost totally linear across the whole movement range, & that is a problem - too much pedal travel. I have maxed out the lever length at the pedal end, so I am now looking at replacing the pulley at the t/b end of things with a "reducing radius" one. That should retain the sensitivity in the early part of the throttle opening, but pull on faster as you get to WOT - all resulting in a shorter overall pedal throw so that I can set the pedal a bit further forward & allow me to "heel & toe" without dislocating my ankle !!

Kind Regards,

Peter D.

dolthoff · 28th December 2006, 08:14 AM

Hi guys.
We are busy with a new cable with a lot less friction.
The problem with most of the early cars is that the installers ran the cable all the way around the back of the motor. This makes the cable about 3 feet longer. This also does not allow for WOT.

We use a link on the side and feed the cable from the front. Works a lot better. This also works for 8 stack injection.

Happy New Year.
Dennis.

Steve Briscoe · 28th December 2006, 08:56 AM

Quote:

Originally Posted by dolthoff

We use a link on the side and feed the cable from the front. Works a lot better. This also works for 8 stack injection.
Happy New Year.
Dennis.

Dennis -
Do you have pictures of this you can post?
Thanks,
Steve

Rick Muck- Mark IV · 28th December 2006, 09:38 AM

The cable running all the way 'round the back is what was on P1116 originally. Worked poorly and the heat from the snakes caused it to bind. After three replacements, my solution was to use a shorter cable that ran up the back of the firewall to a layshaft that mounted under the bulkhead window. This shaft transferred the motion to the left side of the engine allowing a straight rod to operate the Holley. No "monkey motion" and no binding. The layshaft rode in rod-end bearings that attached to the flange under the bulkhead window. Also this allowed the Holley to be mounted in standard posistion (throttle arms on left) rather than reversed as would be required otherwise. This setup will also work with Webers with either the center control throttle or the side setup.

End result was smooth operation with reasonable pressure required even with two return springs (never trust just one) and easy adjustment of WOT and pedal travel.

There are several hydraulic throttle systems sold to the street rod guys that should work well and are compatible with cruise control.

Rick

Jim Rosenthal · 31st December 2006, 01:32 AM

Is the problem there all the time or just when the engine is warmed up....I have this problem on another car and it seems to be that when things get warm the throttle plate binds in the intake bore. It is not in the cable, we think. It may have to do with alignment of the throttle plate.