Hey I'm running a 89 x 81.5 ls vtec and wondering if I could benefit from running a 23 inch tire?
I'm just not sure if I have enough jam. Making 212/141 tuned on free crome and weighs 2090lbs with me and fuel.
Best ET so far is 12.63@104 with a 1.73 60ft launching @7500 that's on a 22x8x13 MT.
Cheers Thx.

 

I'm running a 23x7.5x15 m&h right now on a very similar build as you. 207/135 revving to 8900

Going down to a 22x8.5x13 because i finish at like 6800 in 4th. Smaller tire should put me more into the higher part of my power band.

What rpm you passing the line at?

 

I'm at 8000rpm B16 tranny

 

Is that your redline or what you're passing the traps at? You should have no problems with a 23" tire. I'm only making 226whp and I'm using a 24.5" tire with no problems and 1.66 60'. A 23" would better my 60' but would mean I need to up my rev limit about 300rpm to cross the traps in 4th.

 

At your power level, I think your best with a 22" tire. I am 300whp with a 23x8.5 and I am debating trying a smaller tire.

 

what transmission do you have and what final drive? And where is your redline?
Id say if your not running out of gear in 4th, Id stick with the 22s, unless you're going to make more power soon. From your mph, it looks like you should still have plenty of gear left.

 

I have a B16 4.40 final drive limiter is at 8700.

 

i would stay with the 22". ideally you want to cross the line as high in 4th gear as possible. going up to a 23" will bring you down farther away from redline.

try messing around with launch rpms, suspension preload, tire psi etc

 

^^^Yes, I agree. Stay with the 22s. On my all motor setup, Im running 22s, have a shorter final drive with shorter 3rd and 4th gears. I go to around 9000 at the end, but trapping 114mph. So if I can do it on 22s with shorter gears, you certainly can regardless of where I top out at.

 

Thx for all the advice I appreciate the input.

 

I disagree with the advice on sticking with the 22"s although I would like to see your dyno and logs to 100% recommend a 23". I 99% (lol) recommend going with 23"s without seeing either.

You want the biggest diameter you can fit (use common sense) before causing the car to bog. You're at 20xx pounds. This will not happen with 23"s.

You will gain trap speed and better 60's. You don't need to over-rev the engine to 9,000 rpms crossing the traps [/b]unless you are making power around that range[/b].

It's beneficial to rev 1-3 out a little more to fall back into your hp/torque "sweet" spot. However, in 4th you don't want to over-rev the engine. Logging will help you figure shift points. I highly recommend it.

 

Church. You hit it dead nuts.

 

I cant agree with that. 22"s are just fine for his power level. Yes, you're right, he could potentionally have higher trap speeds, but he is already going 104 and has plenty of room to go with the transmission/final drive and tire combo. Going with a 23" tires with his transmission is exactly like changing from his 4.4 to a 4.2 final drive. It will only hurt him, he will go slower.

What he needs to do, instead of buying bigger tires is mess with his launch rpm, and tire pressure. Those tires are fully capable getting great 60ft and fast ETs. Ive seen 1.5 60fts on 22s when set up right. I myself have hit 1.6 60ft on my 22s and trapped 114mhp. Plus the owner of these tires before me whent mid 10s with a great 60ft.

With that all being said, you're still right on the rpm crossing the traps. We would want to see the logs to see where he is at on the top. If he is crossing the line and needing to go way above his rev limit, then yes 23s. However, judging by his transmission and final drive combo, I highly doubt he is needing to cross over his 8700 rev limit.

Im not trying to start an arguement, this is just my experience of years of drag racing and extensive research I went through when choosing tires myself. And the results show.

 

The owner of those 22"s did not go mid 10's all motor. We are talking about an all motor car that makes 200-220 whp and weighs 2000 pounds. With 4.40 or 4.7 final I recommend a 23" slick with this setup. If he was making 240 or more I would recommend a 24.5" slick.

Like I tell the others. We are just gonna have to agree to disagree on this bud.

 

Yes, the tires I currently have (22s) were owned by a friend that was in the all motor pro class with a 300+hp all motor k series and went mid to high 10s. It did happen and the fact that you say it didnt tells me that you've never messed with 22s or have never used them or set them up properly. I was there when it happened and I'm pretty sure I can find a video or at least pics of the car at the event when it happened (one showing the tires on the car and one down the track with ET flashing in the back) since im sure you dont believe me. And im sorry for this rant against you, but you kinda pissed me off by telling me those 22s did not go 10s. Basically called me a liar.
I will go a head and agree to disagree. But I strongly feel if he goes up to 23s he will go slower. Its geometry and physics, you cant deny that. 22s can do what he wants. and trust me, at his power level and tranny/final combo they are just fine. He just has to set them up at the track.