bdiroc

hello looking for info on ways to slow car down and stay consistent.

I am running an index class of 13.0 this weekend and car runs mid 12.5's consistent.

should I put a throttle stop on (not illegal in rules that I see) or is there an easy way to do it in the chip programming that wouldn't be super obvious or hurt the car.

the car is a 355 hsr running 6e programming

thanks in advance guys.

FRMULA88

simply increase injection volume at WOT... (ie run it richer)

that will slow it down and not hurt the engine.

hopefully you have time trials before the index class starts or make it to test and tune..

1/2 second is alot running ruch may not cut it.

you can also try short shifting... lower your shift point by 500 RPM..

OR a combination of these two.

Orr89RocZ

iTrader: (20)

I would try taking timing out and maybe short shifting. I wouldnt necessarily dump more fuel to slow it down although that can work for fine tuning

AlkyIROC

Find every small tip on how to go faster and do the opposite providing it doesn't cause a lack of traction like increasing tire pressure.

Retard timing

An electronic throttle stop is probably illegal for the class is it is for most classes but there's nothing to stop you from installing a mechanical stop to prevent the throttle from going to WOT.

Add lots of weight

Short shift. Get into high gear as fast as you can.

Launch from an idle

DIGGLER

iTrader: (1)

add some weight and pull some timing?

KWIK84

iTrader: (5)

add a couple hundred pounds and back shift rpm, and launch down about 500...

bdiroc

thanks guys, good info

it is a private race for local group so rules are not very particular.

you have to do a 30 mile cruise then 20 minute cool down then run 3 back to back runs.

then after that there is bracket racing going on so I change car back after that race.

I am going to put my seats back in for weight , fill car up with gas, and from accidentally having the throttle cable not allow full throttle before and slowing me down three tenths , put it back that way.(it was only allowing about 85% throttle on data log)

then if I need a little more I will pull some timing

thanks guys I will test it tonight

Orr89RocZ

iTrader: (20)

I once accidently forgot to reconnect est wire while setting base timing. That slowed me down .3 on a mid high 13's car.. 4 mph down.

We control power thru timing on boosted cars where a few degs makes huge differences. On a fast na motor it will take a good bit pulled to lose .5 but can be done. Weight is a good idea.

226 lbs loss helped my car gain 2-2.5 mph from 109.x-110 to 112.x. ET dropped a .1 due to spin on 60 ft. Should have went .2-.25 better. I put some interior back in and more gas to where i was only down 120 lbs or so and i gained a tenth. 12.27 to 12.15

bdiroc

also thinking of putting my nitto's back on so I cant 60ft as good, last year when I ran them for a couple of events my 60's where 1.75-1.82., with mt's it 60's in 1.6's. that will end up being a couple tenths for sure just worried about consistency

maybe its not worth messing with , its just for trophy and brag rights, I hate slowing my car down after trying to squeeze every bit of et it had in it last year

If I had more time I would have installed some parts and run the 12 class, just ran out of time. how much do you think I could pickup if I would have installed my xfi 280 cam and put more gear in it (only running 3.5 gear now crossing line way to low of rpm)currently running lpe 211 cam.

Orr89RocZ

iTrader: (20)

If it has good heads it will run 12.0's with 280 cam. Last one i worked on with ok heads went 12.2's suffering from valve float in warmer air. 360" hsr with old school afr 190's. Was a high 11's capable car no doubt. 280 cam needs 4000 stall tho to 60 ft 1.6's. really not alot down below 4000 rpm on a 355

But i would def try making chip with 7-8 deg less timing in the 190-208 lv8 range all across the board. Biggest change is in your launch rpm range. Could drop 10 there and slow 60' enough to see bigger change on big end

unknown_host

iTrader: (1)

Pull 2* of timing and a bunch of weight in the hatch, it would make your car more consistent for bracket racing as it would help it hook up.

PhoenixFirebird

iTrader: (2)

Sounds like the NMCA True Street class. Easiest way to slow down is add weight or restrict throttle from going 100%(make a creative limiter out of extra padding under the pedal or something). Both can be removed quick when you're done.

bdiroc

thanks guy , yes they are copying the nmca rules.

went to track tonight to try some things to slow it down but the air was so good I had to try and run my best time ever. well ran a bunch of 12.40's then last run was a 12.38 @109 with a 1.66 60 ft. was really happy with time, but now i am still not ready for this weekend.

It was my first time out this year and had lots of fun except when i red light 2nd round by .001

mw66nova

iTrader: (13)

-mechanical stop on the throttle so it stops at the same spot every time

-add weight

-shift points

-retard timing

i wouldn't recommend putting bad tires on it cause while it may slow you down, you won't be consistently slow each time (wheel spin is tough to keep consistent).