c-heads and throttle stop racing?

Go down

c-heads and throttle stop racing?

Post  Rickytx630 on August 23rd 2016, 5:54 pm

looking for peoples thoughts on using c460 heads on a 598 with a throttle stop. i know the cheads can flow alot but will it hurt performance with the pull off the stop or will they recover ok? would i be better with an out of the box or mild port work or will a fully ported set be ok? it would be in a chassis car with glass body. say 2300lbs or so car isnt finish yet.

Rickytx630

Posts : 71
Join date : 2016-01-18

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Lem Evans on August 23rd 2016, 6:57 pm

Using the C460 heads will not be an issue in and of it's self. The package just needs the correct Intake & exhaust manifolding, carb, cam, Etc. for the application. The same can be said for most any other cyl. heads.

I think a guy could add valve size and valve job to the list of things to consider in any engine application.


Lem Evans

Posts : 7136
Join date : 2008-12-03
Location : Livermore , Ky

View user profile http://bfevansraceparts.com

Back to top Go down

Re: c-heads and throttle stop racing?

Post  dfree383 on August 23rd 2016, 7:46 pm

I agree with Lem and think you'd be after high velocity smaller ports and wouldn't want to chase big flow numbers
avatar
dfree383
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 14151
Join date : 2009-07-09
Location : Home Wif Da Wife.....

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  BigDave65 on August 23rd 2016, 8:52 pm

Getting a good converter built to work with a T-stop will help a bunch also!
avatar
BigDave65

Posts : 557
Join date : 2009-08-12
Age : 52
Location : Cliffside, NC

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Rickytx630 on August 23rd 2016, 9:24 pm

as far as the intake would go i was planning on using the c460 single 4bbl. part #M-9424-C460. as car as cam profile i havent gotten there yet. i will figure that out when i get the block in. order one yesterday (monday). also. the crab issue im sure its hard to say without having much but was thinking of a 1250 or so. maybe more? not sure.

now. as part of the carb issue and not fully sure as i was thinking of doing this on alky with a rons terminator. my question is would that have any affect on things or would it be just fine. i know some people with dragster run them and seem to do fine.. am i over thinking things?

and for a converter i was planning on getting one made after the motor comes off the dyno to see what it mades and go from there.

Rickytx630

Posts : 71
Join date : 2016-01-18

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  99zx9r on August 26th 2016, 1:08 am

A lot of guys go for big MPH in throttle stop racing, but bottom end is very important too. Here in Div. 1, S/G and S/C are on a .370 tree, which can be hard to hit unless you have a light car (which it sounds like you do) and a lot of low end torque. Especially those tracks with a looser rollout. I've run two motors in my tube chassis tbird (2265 lbs without driver) in S/G and the smaller cube, smaller head motor hits the tree better than the bigger cube/head motor.
avatar
99zx9r

Posts : 39
Join date : 2012-07-25

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  rmcomprandy on August 26th 2016, 8:52 am

Most guys who I have talked with who run that big MPH and spend quite a bit of time on the throttle stop, do it so THEY can be the "chaser" at the stripe.

One of those guys went 8.901 @ 202 MPH. I sure he had enough power everywhere.

rmcomprandy

Posts : 5129
Join date : 2008-12-02
Location : Roseville, Michigan

View user profile http://www.rmcompetition.com

Back to top Go down

Re: c-heads and throttle stop racing?

Post  99zx9r on August 26th 2016, 10:24 am

Definitely good to have ample power everywhere. Running 9.90 @ mid to upper 150s in my small motor, I'm in the middle of the pack MPH wise. The bigger one will do low 160s, but we need to figure out how to improve the hit some.

Good to see BBFs running some .90 stuff.
avatar
99zx9r

Posts : 39
Join date : 2012-07-25

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Rickytx630 on August 27th 2016, 10:20 am

what combos are you running? if you dont mind sharing or giving a little detail on yours?

Rickytx630

Posts : 71
Join date : 2016-01-18

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  99zx9r on August 27th 2016, 6:03 pm

Sure...nothing secret or exotic with my stuff. The car is the one in my avatar - tube chassis, strut front, 14x32 tire, power glide and 9" with 4.11 gears. For motors, I have a 557 with out of the box TFS A Heads. The other is a 618, aluminum rod with ported FMS A Heads. I use a #1 Stop under carb TS which we found to be more consistent than the linkage type. You lose a bit of MPH due to the slight restriction, but it's worth it imo.

This is my first year running S/G and the biggest challenge is getting a good TS ratio. Unlike bracket racing there is no shoe polish to bail you out. And there are so many variables with this type of racing: TS on/off time, cruise RPM, shift point, launch RPM etc. I'm learning it's not easy getting an 8.0 car to run 9.90 consistently and in varying weather conditions (a good weather station is a must). I'm in it for the long haul though and determined to figure it out.
avatar
99zx9r

Posts : 39
Join date : 2012-07-25

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Rickytx630 on August 28th 2016, 11:23 am

nice man. everyone i talked to says go with the #1 stop ts. now as much as i love the .90 races ive actually never paid much attention to the ts them selfs.
so that is all new to me. are they all air? and how often are people refilling the bottles?

Rickytx630

Posts : 71
Join date : 2016-01-18

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  bosshoss on August 28th 2016, 2:22 pm

I run a similar combo in my car. 598, c460, cast motorsport intake by Charlie evans, dedenbear air stop under carb, 1050 gary Stinnett carb.

I have been trying to figure this deal out for 20 plus years and have learned a few hard lessons along the way.

The number one thing in this racket is consistency. you will never get a good ratio figured out until you have a car that will repeat, dead nuts every time.

You need to be able to go .370 at the tree and you have to learn and trust your combo enough to be able to make good decisions at the finish line.

I have seen guys that don't have a consistent car win. However, Those are the guys that can go .010 or less at the tree consistently. After they beat you off the starting line they attempt to keep less than a fender on you at the finish. With practice the good ones do well.

Most guys try to run pretty honest. Get a decent light and set the car up to run 9.87 or so. Then at the finish you can decide wether to dump or back in. Not many who can successfully hit the .900 every time. Some try but with limited success in my observation. Check out the national event ladders, the consistent winners in all the super classes win on double breakouts as often as not.

If it was easy everyone would be doing it I guess... cut a lite, run a .90. Pretty simple...

One thing a lot of new guys seem to miss is that the dead stall rpm will change from race to race based on weather etc. You can not expect your ratio to stay the same if your dead stall changes. Check and reset at least before every event or in the case of big overnight weather changes.

dkp
avatar
bosshoss
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 474
Join date : 2009-08-10

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Rickytx630 on August 28th 2016, 6:07 pm

very good info and thanks. and only a 1050 on the 598? is it build for your combo or just everything else is over kill? 1150 1250 etc?

Rickytx630

Posts : 71
Join date : 2016-01-18

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  bosshoss on August 28th 2016, 6:14 pm

Gary Stinnett wins races and builds throttle stop carbs for a living. I took his word for it.

Back to back on the dyno a 1250 qft made about 20hp over the 1050.

Qft would stumble coming off the stop 1050 doesn't.

dkp

the 1050 wide open went 7.97 @ 171 in my new 2400 pound roadster this year. 165 at 9.90

Very Happy
avatar
bosshoss
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 474
Join date : 2009-08-10

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Rickytx630 on August 29th 2016, 1:06 pm

cant argue with that.

Rickytx630

Posts : 71
Join date : 2016-01-18

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Lem Evans on August 29th 2016, 5:42 pm

bosshoss wrote:Gary Stinnett wins races and builds throttle stop carbs for a living. I took his word for it.

Back to back on the dyno a 1250 qft made about 20hp over the 1050.

Qft would stumble coming off the stop   1050 doesn't.

dkp

the 1050 wide open went 7.97 @ 171 in my new 2400 pound roadster this year.  165 at 9.90

Very Happy

was the QFT carb a Hp style body or a QFX?

Lem Evans

Posts : 7136
Join date : 2008-12-03
Location : Livermore , Ky

View user profile http://bfevansraceparts.com

Back to top Go down

Re: c-heads and throttle stop racing?

Post  bosshoss on August 29th 2016, 8:16 pm

It was regular QFT 1250 Lem. Did not have the four bolt flange on the air cleaner ring

avatar
bosshoss
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 474
Join date : 2009-08-10

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Lem Evans on August 29th 2016, 8:28 pm

bosshoss wrote:It was regular QFT 1250 Lem. Did not have the four bolt flange on the air cleaner ring


I suspected that it was the older holley based unit.

Lem Evans

Posts : 7136
Join date : 2008-12-03
Location : Livermore , Ky

View user profile http://bfevansraceparts.com

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Lem Evans on August 29th 2016, 8:34 pm

Looks like I could be a throttle stop expert.....just keep putting a smaller carb on it until it works.

Lem Evans

Posts : 7136
Join date : 2008-12-03
Location : Livermore , Ky

View user profile http://bfevansraceparts.com

Back to top Go down

Re: c-heads and throttle stop racing?

Post  bosshoss on August 29th 2016, 8:43 pm

LOL. The 1050 looks like an out the box Holley unit but I think Stinnett does some work on the metering plates. Also Intermediate airbleeds have been removed. The big rage these days seems to be the new deal from APD with the built in linkage system. All the cool kids have one. cheers

dkp
avatar
bosshoss
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 474
Join date : 2009-08-10

View user profile

Back to top Go down

Re: c-heads and throttle stop racing?

Post  Lem Evans on August 29th 2016, 8:59 pm

bosshoss wrote:LOL.  The 1050 looks like an out the box Holley unit but I think Stinnett does some work on the metering plates. Also Intermediate airbleeds have been removed. The big rage these days seems to be the new deal from APD with the built in linkage system. All the cool kids have one.   cheers

dkp

I know a guy knows WTF is going on and that APD/John Kyle thing is for real.

Lem Evans

Posts : 7136
Join date : 2008-12-03
Location : Livermore , Ky

View user profile http://bfevansraceparts.com

Back to top Go down

Re: c-heads and throttle stop racing?

Post  bosshoss on August 29th 2016, 9:15 pm

yeah I am hearing they are good for a few mph at the finish line.
avatar
bosshoss
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 474
Join date : 2009-08-10

View user profile

Back to top Go down

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum