BUILD THREAD 86 GP 2+2~Blown 6.0

[Supercharged111]

If your peak HP is at 6700, you need to be shifting more like 7000, not a mere 100 past peak. Maybe even a little higher.

 

[Streetbu]

I understand your thought behind changing gears, but I think you'll be chasing spinning tires now with more gear ratio.... I would've only changed the shocks and your shift rpm and see what that did. Wholesale changes can be hard to quantify and get settled when done all at the same time.. JMO

 

[Northernregal]

If you had a 9" I'd send you my 4.33 spare gear set....

 

[64nailhead]

motorheadmike Streetbu
I think these guys are onto something. A lower gear is not going to help traction imo.

I'm in agreement with whomever said it, try the shocks and the additional rpm's before swapping gears. And I don't want to deter you from the gear swap, but be sure that is what is needed.

I think you'd get better bang for your buck with some of these stiff sidewall DOT slicks or similar : https://hoosiertiregp.com/hoosier-quick-time-pro-d-o-t-drag-racing-tire-27-x-10-50-15-lt-17500qtpro/


No matter, whatever you do I'm in for the learning

 

[motorheadmike]

motorheadmike Streetbu
I think these guys are onto something. A lower gear is not going to help traction imo.

I'm in agreement with whomever said it, try the shocks and the additional rpm's before swapping gears. And I don't want to deter you from the gear swap, but be sure that is what is needed.

I think you'd get better bang for your buck with some of these stiff sidewall DOT slicks or similar : https://hoosiertiregp.com/hoosier-quick-time-pro-d-o-t-drag-racing-tire-27-x-10-50-15-lt-17500qtpro/


No matter, whatever you do I'm in for the learning

It's definitely a combination thing.

I agree that a stick car needs a bias ply tire... I cannot begin to express the launch consistency I gained going QTPs - it was night and day over the radials.

But, if he changes the tires, suspension (to match the bias plys), gears, and shift points and gets it all set up properly it should work out fine. There are a lot of compromises currently built into the car. They say making big changes all at once is retarded. But, so is accepting a bunch of compromises and changing nothing. Contradicting philosophies for certain.

Its time to go full retard.

 

[GroceryGetter83]

I can attest to suspension helping out way more than I envisioned! It will be interesting to see how this all shakes out.

I am wrapping up my Viking double-adjustable coilovers in the rear (Crusader valving per Trick Chassis) and I'm excited to report back my improvements.

 

[81cutlass]

Watch your charge air temps with the added rotor speed... you might end up losing power if efficiency falls off.



How much time do you anticipate losing during your shifts? The mechanical advantage of the gears will be an improvement, but you still have a set amount of time off power. The gears will help with maintaining the acceleration rate... but, not as much as more power.



I feel targeted by that power leather seat comment... and somehow feel challenged to run a 10.9? (I wish I could have 4.56s.)

I look forward to seeing this project progress into the car you will make it become.

I hear you on IAT temp. I have spun it to 6700 once and slowed down but that was due to bat fueling (10.5 afr).

It seems to me more sensitive to ambient air temp than boost pressure or rpm, but I don't have enough data to say for sure. My iat's stay below 160f at 10 or 11.5 psi, I'd be concerned if it creeps above 180f. I can pulley down if it gets worrisome.

Honestly I don't know how much time I loose shifting. Good point, no good answer on my end.

Yes, it is a challenge I'm excited to get the car consistent and at it's full potential.

If your peak HP is at 6700, you need to be shifting more like 7000, not a mere 100 past peak. Maybe even a little higher.

Yeah the dyno charts I have seen are peak power pretty much flat from 6600-7000. I want to figure out 6750 shifts before 7k though lol!!

I think I've been leaving a lot of power on the table shifting so early.

I understand your thought behind changing gears, but I think you'll be chasing spinning tires now with more gear ratio.... I would've only changed the shocks and your shift rpm and see what that did. Wholesale changes can be hard to quantify and get settled when done all at the same time.. JMO

I hear you on that. I really don't like making multiple changes at the same time. I'm just in a spot where there aren't many track opportunities left and lots to do.

The gear change is an attempt to get my rpm out of rod bendy territory and avoid the bog about 80ft out when my clutch fully couples.

I do like the shocks + rpm and gears later idea. I was mentally thinking shift rpm and gears have to be done at the same time but they absolutely don't need to be.

If you had a 9" I'd send you my 4.33 spare gear set....

Finally, useable 9" parts not just 5.83 dirt track spools

First time I wish I had a 9!

motorheadmike Streetbu
I think these guys are onto something. A lower gear is not going to help traction imo.

I'm in agreement with whomever said it, try the shocks and the additional rpm's before swapping gears. And I don't want to deter you from the gear swap, but be sure that is what is needed.

I think you'd get better bang for your buck with some of these stiff sidewall DOT slicks or similar : https://hoosiertiregp.com/hoosier-quick-time-pro-d-o-t-drag-racing-tire-27-x-10-50-15-lt-17500qtpro/


No matter, whatever you do I'm in for the learning

Totally, I'm up to learn!

My gear change thing is honestly spurred by a cousin of mine who had a centri lt1 T/A stick car years back that exhibited the same things my car does. He went from 3.73 to 4.33 and instantly went from 11.60 to 10.70. He was confident stick cars are much more picky to the correct gears to get the engine in the right rpm range and said to fix that first thing.

The bias dot slick is in my back pocket. I'm happy so far with my clutch slipper and radial but it's 100% on the table.

It's definitely a combination thing.

I agree that a stick car needs a bias ply tire... I cannot begin to express the launch consistency I gained going QTPs - it was night and day over the radials.

But, if he changes the tires, suspension (to match the bias plys), gears, and shift points and gets it all set up properly it should work out fine. There are a lot of compromises currently built into the car. They say making big changes all at once is retarded. But, so is accepting a bunch of compromises and changing nothing. Contradicting philosophies for certain.

Its time to go full retard.

Abso-fricken-lutely! Throw caution to the wind, and guess in the name of my game haha.

I can attest to suspension helping out way more than I envisioned! It will be interesting to see how this all shakes out.

I am wrapping up my Viking double-adjustable coilovers in the rear (Crusader valving per Trick Chassis) and I'm excited to report back my improvements.

Do you have adjustable viking fronts? Curious the settings your at if you don't mind sharing.

 

[motorheadmike]

I hear you on IAT temp. I have spun it to 6700 once and slowed down but that was due to bat fueling (10.5 afr).

It seems to me more sensitive to ambient air temp than boost pressure or rpm, but I don't have enough data to say for sure. My iat's stay below 160f at 10 or 11.5 psi, I'd be concerned if it creeps above 180f. I can pulley down if it gets worrisome.

Meth and/or nitrous will solve that.

Honestly I don't know how much time I loose shifting. Good point, no good answer on my end.

Open HPTuners and measure the off/on throttle time in your logs. Simple as that to gain a baseline.

My gear change thing is honestly spurred by a cousin of mine who had a centri lt1 T/A stick car years back that exhibited the same things my car does. He went from 3.73 to 4.33 and instantly went from 11.60 to 10.70. He was confident stick cars are much more picky to the correct gears to get the engine in the right rpm range and said to fix that first thing.

When I went from 3.42s to 4.56s in my MCSS it turned a mid-13 second car into a mid-12 second car. Same with Natasha's old B4C going from 3.08s to 4.11s. There is a huge mechanical advantage waiting back there.

If I had the means I would put the Scat Pack/392 TR6060 and 3.90 gears in the HellKitty... the math demands it.

 

[64nailhead]

When I went from 3.42s to 4.56s in my MCSS it turned a mid-13 second car into a mid-12 second car. Same with Natasha's old B4C going from 3.08s to 4.11s. There is a huge mechanical advantage waiting back there.

If I had the means I would put the Scat Pack/392 TR6060 and 3.90 gears in the HellKitty... the math demands it.

This is what I'm interested to see. A NA car or turbo car builds a ton of torque in the higher rpm range, but Jake's blower puts the power through the roof at 3500 as compared to either.

Personally, I have no idea whether more gear will help, or hopefully not hurt. I have the same lack of knowledge regarding tuning the timing with a blown setup because the tuning mentality is just the opposite of what I'm doing. Meaning, I'm doing everything in my power to cut HP below peak torque (5000) and also trying to let it live for the entire run between 6000-7500. The stick setup makes that a difficult task AFAIC. Basically, despite this being a boosted LS, it's a completely different animal than a turbo with an automatic.

Like I said, I'm down with learning. And it sounds we are all going to learn something about this before long - thanks to 81cutlass .

 

[Streetbu]

It's definitely a combination thing.

I agree that a stick car needs a bias ply tire... I cannot begin to express the launch consistency I gained going QTPs - it was night and day over the radials.

But, if he changes the tires, suspension (to match the bias plys), gears, and shift points and gets it all set up properly it should work out fine. There are a lot of compromises currently built into the car. They say making big changes all at once is retarded. But, so is accepting a bunch of compromises and changing nothing. Contradicting philosophies for certain.

Its time to go full retard.

The entire car is a compromise. It has to be in order to drag race, corner, and street car. The more you optimize one, the more you take away from another.