IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: Scoobum on December 20 2014, 08:43:21 AM
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Thot this would be a good thread for advice and tips from guys like SW, PACECARTA, Joebuick and Nocooler who have been at it with these cars for eons.
I managed to get my short times down into the high 1.5's. I'd like to lower it to low 1.5's to high 1.4's...off the footbrake.
Here's what I have to work with:
Stock front sway bar
Line lock
All long rear pads
90\10 front shocks
Stock front/rear springs
QA1 single adjustable rear shocks...curre ntly on the number 2 setting
ATR rear bar
Metco billet LCA's
Choice of 28x9 and 28x10.5 slicks...and I'm open to suggestions for tire pressures on the 9 and 10 inch slicks.
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There's a pair of air bags in the rear coils that are coming out...and a new pair of UMI non adjustable rear upper control arms that have arrived with new bushings to be installed as well.
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All i have is pull the front sway bar and maybe go to a 70/30 front shock to see how the car acts. If it is unloading the rear with too much front lift and the front coming back down the 70/30 or something adjustable might keep rear planted. Have you considered moving the battery to trunk? Or a light battery in the front? Any other nonessential weight you can remove?
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Front weight removed has been the air con...with the heater box left intact. Front rims weigh in at 9.5 lbs each. F body rad swap. ATR front fiberglass bumper. LT1 starter.
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First...it takes horsepower to make a good short time better. :) Second, you have to get the hp to the rear tires as quickly as possible. I am probably wrong, but I still think that converter is a bit "soft" for your turbo/combo. Seems like a bit tighter converter or a size bigger turbo would help.
Battery in the trunk, lighter front end, skinnier driver...all that stuff helps because it is simply physics.
Speaking of physics, a set of drops on the lower bars will make it hit the tires a lot harder...make you launch like a '60's super stocker..but a set of these will make the launch more controllable allowing you to feed more hp to the tires without getting crazy off the line. http://www.baselinesuspensions.com/kits/chevy.htm (http://www.baselinesuspensions.com/kits/chevy.htm)
What most forget is the part that it takes hp to leave fast and physics to control it.
You are fast enough that good two way shocks and some patience to dial them in will help dial the "hit" in. You need a launch pad where you can play with it...
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The 6466 turbo is the next step up...but it's only available in a DBB version...whic h chimes in at $2500 Canadian after exchange rate...shippin g etc. I noted that the convertor is around 3400 to spin it...which is another $1500 Canadian for a PTC unit from Dusty...after exchange rate, shipping etc. If you wonder why I'm the only one racing one of these cars up here every weekend...you're getting the idea why. I have cash set aside to get the transmission 'toughened' up...and for the fuel upgrades. I'm gonna have to work with the suspension I have. :)
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How much Boost can you hold at the line! I remember back in the 90's I start using the Hand Brakes to Launch. Damn... it was crazy launching at 15 - 20 psi..
How much are you launching at?
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I'd have to check. Convertor flashes to 3800 leaving the line. I can hold any RPM I want. :)
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I installed the baseline pro kit, ordered the door slammer book and went to the scales. I'm not making near as much power as you and I'm launching in the high 1.5's now. The key with the baseline kit is the bracket that moves the upper control arm attaching point rearward. It shortens the length of the upper control arm allowing for a lesser angle thus moving the instant center closer to the CG.
I am still running stock length lowers with poly bushings from UMI.
http://www.ihadav8.com/forum/index.php?topic=4694.msg66519#msg66519 (http://www.ihadav8.com/forum/index.php?topic=4694.msg66519#msg66519)
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I'm gonna drop the front sway bar and pull the rear air bags...for a start. I pretty much have the track to myself on Mix N Match evenings...so we'll try different things...and report back to make adjustments for the next outing. I won't be making an all out assault till our Thanksgiving weekend...so there's plenty of time to dial it in. :)
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I mulled it a bit and I think 28x9 is plenty of tire. The larger one just takes more power to haul it on the top end. Really a 26 tall might get some in the sixty but give up some at the big end so I'd stay with taller, especially at your power level. The taller loads the turbo up. Have you considered a 3.23 or 3.08 gear? Might be something to play with on one of the desktop dyno programs.
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My next purchase is a pair of 28x9's
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the length of the patch is often more important than the width of the patch..thus the taller tire provides more grip. Once our cars are well into the twelves, the taller tire will usually give better short times and better mph. The additional loading provided by the effectively taller gearing will load the turbo better making more heat and better spool.
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You need to work on your instant centre.
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You need to work on your instant centre.
into Zen, eh?
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Brad - 28x10.5x15 ET Drags, get the stiff walled ones
P/N 3055S
The 28x9 is only a 27" tire.
http://www.mickeythompsontires.com/strip.php?item=ETDrag (http://www.mickeythompsontires.com/strip.php?item=ETDrag)
The stiff walls are recommended for heavier cars. The sidewall should last the life of the tire - where the non-stiff you can murder it quickly. Wandering isn't an issues with the stiff walls either - and they don't grow as much.
I'd start @ 12-13psi cold and see how they do. It'll end up 15-16 hot.
Make sure the front and rear suspension doesn't bind and that the transmission yoke splines aren't twisted.
Once the instant center and anti-squat are in the ball park the car will hook on any decent tire. As always make one change at a time and see how the car responds.
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It is pretty simple really, where the car makes power and how it is put to the ground must be in sync.
It is easy to put power down on a soft launch with a so-so suspension set-up; add more power and it begins to show that not everything is working together. Adding more power is routine, setting up a calculated baseline suspension and then systematically tuning it to the power being made is daunting.
Do the math to calculate your instant centre, anti-squat, and weight transfer rates and you'll be coming out ahead.
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I have pulled many 1.50s, 1.51s and a 1.49 , with 100% stock suspension with just air bags and MT ET streets 255/60/15
on foot brake 3000ptc 10" LU. The converter was the biggest gain from 1.65 to low 1.5s and also making sure that is was not rich on the start.
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OH, come on, Keith! you also went 11.0's on a 60 turbo and a stock downpipe! We all know that is impossible! I am surprised that the vendors have not taken out a contract on you!
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yes Steve and I may be going back to my stock downpipe, and get in the mid 10s, that 3" DP is made " PERFECT" but doesn't work for me. I will just make another plate to accept the 63mm.
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well, that perfect down pipe will not make boost with two different turbos so not all is perfect no matter how many thousands have been made. It is strange that the problem is not easily apparent but since the turbos make a ton of boost with a flat plate installed, something is wrong. Be worth a shot, for sure, to try it with your stock pipe and a plate sized for the turbo hole.
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Brad - 28x10.5x15 ET Drags, get the stiff walled ones
P/N 3055S
The 28x9 is only a 27" tire.
http://www.mickeythompsontires.com/strip.php?item=ETDrag (http://www.mickeythompsontires.com/strip.php?item=ETDrag)
The stiff walls are recommended for heavier cars. The sidewall should last the life of the tire - where the non-stiff you can murder it quickly. Wandering isn't an issues with the stiff walls either - and they don't grow as much.
I'd start @ 12-13psi cold and see how they do. It'll end up 15-16 hot.
Make sure the front and rear suspension doesn't bind and that the transmission yoke splines aren't twisted.
Once the instant center and anti-squat are in the ball park the car will hook on any decent tire. As always make one change at a time and see how the car responds.
Thanks Jeremy. I have a pair of 28x10.5's I'm gonna mount up on these lite weight rims...and we'll have a go at it. Price of new slicks up here is insane...so I'll start hunting up a couple pair of used ones again for next year. Gonna pull the air bags and drop the front sway bar...and see how it responds...and then start making changes to the adjustable rear shocks.
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Jeremy, I went out and checked and the 10.5's I have are the C's. I'll keep and eye out for a pair of S's. Once again...thanks .
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Jeremy, I went out and checked and the 10.5's I have are the C's. I'll keep and eye out for a pair of S's. Once again...thanks .
Brad - those are sport compact tires - don't know how they will work for you.
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The 28x9 is only a 27" tire.
That's an inch taller than what I'm running now. Never met a guy who would say that he couldn't use another inch....
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There's a 28x10.5x15C and a 28x10.5x15S. I assume the S relates to the stiff sidewall?
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Correct - the top of this page has all the info:
http://www.mickeythompsontires.com/strip.php?item=ETDrag (http://www.mickeythompsontires.com/strip.php?item=ETDrag)
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As long as we are adding inches.
http://www.mandhtires.com/M-H-Racemaster-Drag-Slicks/9.0-30.0-15 (http://www.mandhtires.com/M-H-Racemaster-Drag-Slicks/9.0-30.0-15)
http://www.performanceplustire.com/products/otherTires/searchType/searchByBrand/productID/5923/subSection/dragTires/dragTireDataID/316 (http://www.performanceplustire.com/products/otherTires/searchType/searchByBrand/productID/5923/subSection/dragTires/dragTireDataID/316)
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What dose your time slip look like?
Is a low 1.5 possible at your 1/4 mph and ET
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6.72 at 104.67. I haven't maxed this turbo out...there's some left in it. 6.5x is within reach...possib ly 6.3x with a hard launch.
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see why you want to work on your short time.
at 104 your 60 should be 1.4
the track I race at, prep is not to good and a good short times are hard to get at your power level.
The Hellwig bar was my best investment ,but my ET is just 11.8 with a 1.6 60,28-9X15 Hoosier would not hook tell I got the bar,have fun I wont be much help
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Brad - 28x10.5x15 ET Drags, get the stiff walled ones
P/N 3055S
The 28x9 is only a 27" tire.
http://www.mickeythompsontires.com/strip.php?item=ETDrag (http://www.mickeythompsontires.com/strip.php?item=ETDrag)
The stiff walls are recommended for heavier cars. The sidewall should last the life of the tire - where the non-stiff you can murder it quickly. Wandering isn't an issues with the stiff walls either - and they don't grow as much.
I'd start @ 12-13psi cold and see how they do. It'll end up 15-16 hot.
Make sure the front and rear suspension doesn't bind and that the transmission yoke splines aren't twisted.
Once the instant center and anti-squat are in the ball park the car will hook on any decent tire. As always make one change at a time and see how the car responds.
Thanks Jeremy. I have a pair of 28x10.5's I'm gonna mount up on these lite weight rims...and we'll have a go at it. Price of new slicks up here is insane...so I'll start hunting up a couple pair of used ones again for next year. Gonna pull the air bags and drop the front sway bar...and see how it responds...and then start making changes to the adjustable rear shocks.
(http://www.ireitinvestor.com/wp-content/uploads/2014/01/bandaid.jpg)
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Brad - 28x10.5x15 ET Drags, get the stiff walled ones
P/N 3055S
The 28x9 is only a 27" tire.
http://www.mickeythompsontires.com/strip.php?item=ETDrag (http://www.mickeythompsontires.com/strip.php?item=ETDrag)
The stiff walls are recommended for heavier cars. The sidewall should last the life of the tire - where the non-stiff you can murder it quickly. Wandering isn't an issues with the stiff walls either - and they don't grow as much.
I'd start @ 12-13psi cold and see how they do. It'll end up 15-16 hot.
Make sure the front and rear suspension doesn't bind and that the transmission yoke splines aren't twisted.
Once the instant center and anti-squat are in the ball park the car will hook on any decent tire. As always make one change at a time and see how the car responds.
Jeremy, I`ll have to get a price on those slicks from my buddy at the speed shop. This new guy at the front desk at my local tire shop was absolutely clueless as to what I was asking for. The other gentleman that worked there was an ex drag racer...and could locate what I wanted in minutes.
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see why you want to work on your short time.
at 104 your 60 should be 1.4
the track I race at, prep is not to good and a good short times are hard to get at your power level.
The Hellwig bar was my best investment ,but my ET is just 11.8 with a 1.6 60,28-9X15 Hoosier would not hook tell I got the bar,have fun I wont be much help
I just ordered the Helwig bar from my local parts store. $320.00 freight and taxes in Canadian
Looking to see if it helps got some slicks to try too.
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Scoobum is your short time bad because you cant get traction when you try to leave harder?
When is started with 255 MT DR I did not have the power off the line to spin the tires but i had a good mph at the top.
I added 1* timing and suddenly the 255 would not hold no mater what I did to the air bags,It took a set of slicks and sway bar
Most people run 10.5 tires because track prep just is not good
Maybe I mist it is it a traction problem or power that hurting your short time
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I've pretty much run the 9 inch slick exclusively. What I haven't checked...is if it's moving on the rim. I'll be going with the 10.5's...as I've been able to get them to fit without hitting the wheel lip or frame rail. I'm patient when it comes to stuff like this. I'll get it dialed in...and I'm not the least bit afraid to go north of 30 PSI to get it done. :)
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You'll like the stiff walls - they don't feel like you are riding on pillows, high speed stability is amazing.
On a marginal track - slicks win every time. I hear guys complaining about drag radial not hooking, track isn't prep'd, blah, blah - I get up there and drop the clutch and hang the fronts.
You'll find the weak links in the drive line for sure :)
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I tried a pair of Hoosier 28" DR's...at different tire pressures...an d leaving at different RPM's. Spun 'em the length of the grandstand each time. Went back to the slicks and the car hooked no problem.
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How about tune? Less fuel in 1st more timing if it's hooking?
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How about doing it properly? :icon_eyes:
(http://www.wallaceracing.com/image002.jpg)
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How about tune? Less fuel in 1st more timing if it's hooking?
Exactly. You can only take what the track will give you.
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Which 10.5" were you able to fit without modds Scoobbum?
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How about doing it properly? :icon_eyes:
(http://www.wallaceracing.com/image002.jpg)
Mike - I don't think anyone is disagreeing with you. I do think he's at the point that relocation will help.
But there are a couple things to consider. What works on one car might not work on another. Power, power delivery (torque converter), tires, track conditions, all come into play.
Brad's times aren't horrible and they were on worn out slicks on a less than marginal surface.
He's stated he wants to start with tires and test, and make changes as necessary. Plenty of guys have went fast with the stock mounting points - I'd try it before relocating stuff.
With the way winter is going this year he might be racing again in April and that will give him plenty of time to test and get it sorted out.
I guess what I'm saying is he could make a ton of changes now and chase his ass all race season or change one thing at a time and figure out what works best for his car.
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2014 F.A.S.T. and Factory Stock Muscle Car Racing from US 131 Motorsports Park in Martin Michigan (http://www.youtube.com/watch?v=b62oOrX9HKs#ws)
This isn't about making changes, it is about knowing what you have and how it can be changed. But, if you don't baseline the car's suspension fancy cool-guy tires are just going to mask the underlying issue. The video at the top of this post very clearly explains the need to tune to either crap tires, a crap track, or both and still be stupid fast with a very powerful car.
In autocross/road racing you do not simply bolt on hero tires and make bonzai runs - you baseline and tweak the suspension to a normal set of tires and work your way up to racing tires.
To be clear I am not questioning Brad's ability or successes, I am poo-pooing on the Winter-time bench racing session that is happening here about what tires and what tire pressure to run. Bring the real tech, or at least the knowledge of it...
A set of weld in relocation brackets from UMI are about 1/5" the cost of one slick, and a set of offset bushings for the upper differential ears are $40 from Speedway - hardly a huge investment in time or money. I say this because the only way to fit a true 10.5" slick under a stock-frame/stock-body Regal is to jack the rear of the car up; and that screws with the geometry.
There are tonnes of fast "small tire" cars who found their success in suspension tuning.
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Last time I checked Mike - 10.5's were small tires :rolleyes; they are nearly the same size as a "true" 275/60/15 - in some cases they are half an inch wider.
I guess we can disagree. The 1st mod to a car that you are drag racing should be a proper set of drag tires. You don't need the biggest set of tires that you can fit - but a set of drag radials or slicks are going to net you the biggest 60' change for the money.
IMO Brad could benefit from the 10.5 tire I suggested due to the stiff sidewall - they don't make a stiff sidewall in anything other than a 10.5 in the 28" tire size.
Could he benefit from relocation? Probably - and he has said he's prepared to buy those parts if the tire doesn't help. Just cause some brackets work on one car doesn't mean they will work on every car at every power level at every track. Having adjustability doesn't hurt but you need to be able to review data and make changes from there. Sure he could plot it out at ride height once he gets his new tires and set everything up to someone's best guess and it might be close, but there will always be tuning needed once he has some data at the track.
If anything I'd start with Baseline's upper relocation boxes. He doesn't need to move the lowers unless the car is lowered or unless he needs more anti squat IMO.
Maybe we should all go back to running southside lowers :rolleyes;
Oh and in case you didn't know different tires will require different suspension geometry's to work. Drag radial need stupid amounts of anti squat to work at moderate to high horsepower levels.
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Oh I think we are agreeing in principle; I just want to expand the conversation. Tire talk has been beat to death over the years - we need to take it up a level like Jason did earlier this year.
This is why I started doing all the work to the rear suspension in our wagon - to better explore our options on this platform.
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I love threads like this always useful information.
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Oh I think we are agreeing in principle; I just want to expand the conversation. Tire talk has been beat to death over the years - we need to take it up a level like Jason did earlier this year.
This is why I started doing all the work to the rear suspension in our wagon - to better explore our options on this platform.
I'm looking forward to the s60 install on the wagon.
I got turned on to some offset bushings i want to try and am searching for a cheap atr rear bar.
I guess I didn't understand that the 9" slick isn't hooking.
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I'm no expert on this, and this may be common knowledge, but i wish I would have started my suspension in this sequence:
Set ride height, springs or adjustable like the QA1's
Wheel/tire selection
[/size]Upgrade the brakes front and rear so you can stop and hold some boost at the lineYour choice of rear UCA front adjustable relocation brackets ( I used the baseline brackets )Your choice of adjustable UCA ( I used the baseline UCA )Your choice of boxed LCA. Nothing wrong with boxing the stockersRear LCA adjustable brackets mounted to the axle. Poly bushings all around. I didn't install the offset bushing in the axleYour choice of rear stabilizer bar like the hellwig design.
With the adjustability of the UCA, you can center the axle, set pinion angle and add preload to the right tire. With the adjustability of mounting locations for both the front UCA and the rear LCA, you'll be able to nail the instant center and adjust for squat. From there you can play with weight as in moving it around the car to see what will give you the best results. [/font]
Again, no expert and my thoughts may be flawed[/font]