DSE steering rack ratio

[Vogelsong]

Does anyone know the steering ratio of this rack?

They don’t really mention it on their page.

https://www.detroitspeed.com/21-5-detroit-tuned-power-rack-pinion-detroit-speed-aluma-frame-chevy-ii-front-frame-090220

185472

[dhutton]

20:1 as far as I can recall.

Don

[Mark@lateral-dynamics]

My understanding is that it is a 20:1 as well. We actually have one in the shop, purchased several years ago. It seems to have a significant internal steering stop, the amount of full lock angle is really "low." Will validate that in a comparison with an AGR Cobra rack in the next few days.

Most of the other SN-95 racks are 15:1 with some being even quicker. I read somewhere that DSE uses shorter steering arms to accommodate the slower ratio so keep that in mind too, have not validated but it would make sense.

[Twentyover]

Don't you need a steering arm to calculate rack ratio? I do see that these are to be paired with an alumiframe front end, that steering arm would provide a ratio.

I have seen rack travel /revolution before.

And 20:1 seems awfully slow, particularly if you autocross a car

[dhutton]

And 20:1 seems awfully slow, particularly if you autocross a car

David Pozzi has complained about the DSE rack being slow but he has it on an Art Morrison subframe.

Don

[Mark@lateral-dynamics]

Quick note about the steering stops, well, most likely. For sure the AGR Cobra style rack, on my setup, has at least 3 degrees of additional steering angle, at full lock, inside tire. Reasonable measurement method but not 100% accurate, good enough to see quite a difference though.

[WOLF1732]

Yes you do need steering arms to calculate rack ratio. That has been my issue with most all of the "rack manufactures" flaming river, DSE, ect,ect they claim a ratio but wont give you the gain per revolution. One of the few rack mfg that you can pick you ratio is Woodward. but it's 4k. OUCH !! So In my build I need 10:1 best could live with 12:1 that puts me down to a 4.156 long steering arm to make that happen with an off the shelf rack. Not ideal, and with 345 front tires that also gets you playing games with steering arm position for bump steer and ackerman angle not to mention hydraulic load on the rack. The other option that you can use is a steering quickener. I lot of my off road customers run these on their trucks. I am struggling with these issues myself right now.

[Vogelsong]

Thanks for the insight guys.

I’ll keep all this in mind when planning this part of my build.