[RFM 40th V6]

I took my GT to the track last friday and this firday.

Mods are: CAI, 70MM TB/Plenum, Hitech stage 2 cams, MHS stage 3 heads, BBK LT's o/r H pipe and a pro 5.0 shifter.

I was data logging to dial in the tune via laptop and Predator tuner.

The first friday I went I used my street tires set to 28 PSI. 60' was from 2.3-2.4
First run 13.93 @ 103 Untuned
2nd 13.78 @ 107 Leaned up the mixture a bit and moved up my spark from 17* to 25*
3rd 14.3 @ 103 Leaned it up some more but missed 2nd

Currently I am running a 13.23:1 A/F ratio.

Now here's where it throws me for a loop.

Same mods, same tune, now on BFG T/A Gforce DR's running 25 PSI

Couldn't get out of the 13.8X and most of the time ran a 13.9x Always trapped at 103+ though

Swapped to my friends new Nitto 555R DRs running 22 PSI and ran a best of 13.72 @ 103

60' ranged from 2.1-2.3

It was a good bit more humid this time at the track though.

I'm totally stumped on this one. Is it the humidity? Perhaps the lane? (was put in the right lane all the time) Tire pressure up too high? Maybe I should keep more fuel and then see if my spark advance comes up a bit more? Maybe I need to put in these 3.73's that I have to make better use of my powerband.

I just don't understand how my car is going this slow with this much work into it. I was cutting 14.00s at 102 with a 2.4 60' before the H/C/E. And how is it that my Second run, where I had just begun tuning was better than my tuned run on DR's?

I don't get it. Any ideas?

[Danimal120]

FOR SURE toss in those 3.73's. It'll take your time down a few tenths.

[Jobra]

Dyno tune could help?

Humidity absolutely plays a part. How hard were you banging gears man?

[RFM 40th V6]

I wasn't power sifting her. I was just going like I would under wot on the street. I plan to get her dynoed soon. Just gotta save up. It's like 650. For the tune.

Oh and I was shifting at 5800 to 6000'rpm max.

[wicked96gt]

put the 3.73s in. and get it dyno tuned once you get the money saved up for that.

[RFM 40th V6]

I the main issue is the tune since I can't adjust spark and fuel tables fully. I installed a 180* thermostat and mad the engine run cooler. That brought my spark up from 27* to about 38* on 93.

Gonna do gears this Saturday and try again. Once thats done Ill let it go til I get it dynoed

[Abdullagt]

Swap the gears, Try running less pressure in the Drag radials. Those 555R's need to get hot and sticky so do a good burnout.

[OH03GT]

Originally Posted by RFM 40th V6 I took my GT to the track last friday and this firday. Mods are: CAI, 70MM TB/Plenum, Hitech stage 2 cams, MHS stage 3 heads, BBK LT's o/r H pipe and a pro 5.0 shifter. I was data logging to dial in the tune via laptop and Predator tuner. The first friday I went I used my street tires set to 28 PSI. 60' was from 2.3-2.4 First run 13.93 @ 103 Untuned 2nd 13.78 @ 107 Leaned up the mixture a bit and moved up my spark from 17* to 25* 3rd 14.3 @ 103 Leaned it up some more but missed 2nd Currently I am running a 13.23:1 A/F ratio. Now here's where it throws me for a loop. Same mods, same tune, now on BFG T/A Gforce DR's running 25 PSI Couldn't get out of the 13.8X and most of the time ran a 13.9x Always trapped at 103+ though Swapped to my friends new Nitto 555R DRs running 22 PSI and ran a best of 13.72 @ 103 60' ranged from 2.1-2.3 It was a good bit more humid this time at the track though. I'm totally stumped on this one. Is it the humidity? Perhaps the lane? (was put in the right lane all the time) Tire pressure up too high? Maybe I should keep more fuel and then see if my spark advance comes up a bit more? Maybe I need to put in these 3.73's that I have to make better use of my powerband. I just don't understand how my car is going this slow with this much work into it. I was cutting 14.00s at 102 with a 2.4 60' before the H/C/E. And how is it that my Second run, where I had just begun tuning was better than my tuned run on DR's? I don't get it. Any ideas?

A) theres your problem right there. that combo will never work together. The HiTech Stage 2 cams were made for STOCK heads. Stage 3 heads would perform nicely with a better profile cam. Get rid of the HiTechs and get a pair of cams that will compliment the heads and you will have better times.

B) throw out the 3.73 and go 4.10s

C) get rid of the DR's and throw on a pair of full slicks

D) beef up your rear end to run full slicks as well

[casper gt]

hi techs are at best break even cams at the track, I've never seen anyone pick up more than 1 tenth with them, so they don't really factor into your problem (as in whatever you thought you were gonna gain just isn't there, those cams work best for the young guys that want to impress their buddies at the local cruise spot with the sound).
I'd say your not doing too bad with stock gears, but the 3.73's will help (don't make another rookie mistake & put 4.10's in) but you'll need to think about slicks/bias ply DOT tires before you are shopping for rearend parts on D/R's.

[RFM 40th V6]

Originally Posted by OH03GT A) theres your problem right there. that combo will never work together. The HiTech Stage 2 cams were made for STOCK heads. Stage 3 heads would perform nicely with a better profile cam. Get rid of the HiTechs and get a pair of cams that will compliment the heads and you will have better times. B) throw out the 3.73 and go 4.10s C) get rid of the DR's and throw on a pair of full slicks D) beef up your rear end to run full slicks as well

Actually they are stock heads, they are just ported to the largest profile possible and have extremely strong valve springs in them.

And the Hi tech stage 2 is very similar to the 46PI STAGE 3R cam they offer.

Just for comparison here is the Hi tech stage 2 cam specs vs the 46PI STAGE 3R.

Hi Tech Stage 2
234/230 @ .050 DUR 545/495 Lift 111 Intake Centerline

46PI STAGE 3R
233/230 @.050 DUR 550/525 Lift 111 Intake Centerline

So overall the difference between the two is one more degree of intake rotation on the hi techs and .005/.030 on the exhaust of the 3R.

Since I didn't do a built bottom end I couldn't run anything larger than the 3R or hi tech without PTV issues.

Although the MHS site does say this about the 3R "This is a retarded intake centerline version of the Stage 3 NA cam. Doing this allows this cam duration to be used with a stock piston and modified intake valves with our minimum recommended clearance. This is the largest NA cam we offer than can be used with a stock piston with the 4.6 PI head. Higher flow fuel injectors and long tube headers are recommended. Mild to rough idle. Rear gear of 4.10 minimum recommended."

[RFM 40th V6]

Originally Posted by casper gt hi techs are at best break even cams at the track, I've never seen anyone pick up more than 1 tenth with them, so they don't really factor into your problem (as in whatever you thought you were gonna gain just isn't there, those cams work best for the young guys that want to impress their buddies at the local cruise spot with the sound). I'd say your not doing too bad with stock gears, but the 3.73's will help (don't make another rookie mistake & put 4.10's in) but you'll need to think about slicks/bias ply DOT tires before you are shopping for rearend parts on D/R's.

I figured the 3.73's would be better because I would have a semi usable first gear then. I know I was running way too high of a tire pressure now, which is why I couldn't get a decent hook.

Either way I think I've gotten it down to this as my issues for why it's not at least a low 13.

I need, 3.73's, less pressure in the tires, bigger injectors, a dyno tune to get my spark and fuel tables adjusted perfectly, and better tires such as a slick.

I don't think 12.9 to 12.8 is unimaginable with this setup and the other parts that I've come up with.

Oh and the built rear is in the works. Looking into 31 splines and a tru track.

[casper gt]

don't know what the whole point of the MHS comparison was, but the bottom line is that hi-techs don't make a ton of power so your times seem reasonable.
as to the 4.10/stick thing, at the track you never want to spin outside your power band, a stick & 4.10's on 26" tall tires with your combo is tough to keep the rpm's down, the car will be faster with the average driver & 3.73's.

[casper gt]

Originally Posted by RFM 40th V6 I figured the 3.73's would be better because I would have a semi usable first gear then. I know I was running way too high of a tire pressure now, which is why I couldn't get a decent hook. Either way I think I've gotten it down to this as my issues for why it's not at least a low 13. I need, 3.73's, less pressure in the tires, bigger injectors, a dyno tune to get my spark and fuel tables adjusted perfectly, and better tires such as a slick. I don't think 12.9 to 12.8 is unimaginable with this setup and the other parts that I've come up with. Oh and the built rear is in the works. Looking into 31 splines and a tru track.

that doesn't sound bad but as to the tire pressure, if your spinning you can lower it, if your not spinning leave it alone, I've been 1.72 60' on 555r's with 24psi.
your not even close to needing bigger injectors, the 19's will be fine.
high 12's are very doable once you get it sorted out.

[RFM 40th V6]

I understand about the gears. It will be helpful when I have a dyno sheet so I can see exactly where I need to shift. I've gone back to 5800 rpm for now, seeing as the HI tech sample dyno sheet starts to drop power around there.

The comparison was to show that the're isn't a huge difference between the hi tech and the MHS cam that was designed to work with the heads I have.

It's going to get new cams when it gets blown, so I'll make a better choice then. I was under the impression that the Hi techs were a rather good cam for street strip use and made decent power.

Or at least that's what I was told by several people.

[casper gt]

Originally Posted by RFM 40th V6 I understand about the gears. It will be helpful when I have a dyno sheet so I can see exactly where I need to shift. I've gone back to 5800 rpm for now, seeing as the HI tech sample dyno sheet starts to drop power around there. The comparison was to show that the're isn't a huge difference between the hi tech and the MHS cam that was designed to work with the heads I have. It's going to get new cams when it gets blown, so I'll make a better choice then. I was under the impression that the Hi techs were a rather good cam for street strip use and made decent power. Or at least that's what I was told by several people.

thats the general though from guy's who think they know, but ask some who spend time at the track (actually racing) & you'll get a diffrent story, theres much better cams out there.
that being said though, their in there, no point in talking about better/etc., just sort out what you have & you'll be good.

[OH03GT]

Originally Posted by casper gt hi techs are at best break even cams at the track, I've never seen anyone pick up more than 1 tenth with them, so they don't really factor into your problem (as in whatever you thought you were gonna gain just isn't there, those cams work best for the young guys that want to impress their buddies at the local cruise spot with the sound). I'd say your not doing too bad with stock gears, but the 3.73's will help (don't make another rookie mistake & put 4.10's in) but you'll need to think about slicks/bias ply DOT tires before you are shopping for rearend parts on D/R's.

not going to argue just giving my point of view
1st - On

this run

this run

with a crappy 4200rpm launch i trapped at 13.44@104mph - thats 3 tenths quicker than what i used to run. now keep in mind this was only ONE run. I dont know if my cams helped that out or the new 4.10 gears or what. but i do know on that crappy launch i did wayy better than i did ALL last year.

2nd - Im just curious as to how 4.10s are a rookie mistake? enlighten me please

3rd - Why wouldnt he need to beef up his rear end before running slicks? and launching higher? Maybe because he will run 3.73s? launch at a lower rpms? There are various articles that say slicks are easier on your drivetrain, with my experience the combo of 4.10s - slicks - stock rear end - and launching in the mid 5000rpms caused me to snap my driver side axle and differential bearing.

i know you know what your talkin about casper - im just confused on some points

[OH03GT]

To the OP since you plan on gettin blown later down the road im not going to argue your point of where your at now. i do hope you get that car going alot quicker than what it is now. good luck to you on that!

[RFM 40th V6]

I appreciate the input and all. I realize that the cams were probably not quite the best choice but since it's what I have installed and it's what I have to work with now I'll make do. I'll be happy if I can get 12.8x out this. That was really my only goal for this mild build any way.

I still feel that a lot of my problem lies with in my tune. Being such that I can't adjust everything the way a pro can.

[casper gt]

Originally Posted by OH03GT not going to argue just giving my point of view 1st - On this run with a crappy 4200rpm launch i trapped at 13.44@104mph - thats 3 tenths quicker than what i used to run. now keep in mind this was only ONE run. I dont know if my cams helped that out or the new 4.10 gears or what. but i do know on that crappy launch i did wayy better than i did ALL last year. 2nd - Im just curious as to how 4.10s are a rookie mistake? enlighten me please 3rd - Why wouldnt he need to beef up his rear end before running slicks? and launching higher? Maybe because he will run 3.73s? launch at a lower rpms? There are various articles that say slicks are easier on your drivetrain, with my experience the combo of 4.10s - slicks - stock rear end - and launching in the mid 5000rpms caused me to snap my driver side axle and differential bearing. i know you know what your talkin about casper - im just confused on some points

the reason I say that 4.10s in a stick car at the track are a "rookie mistake" is that are for the rpm issues that I mentioned, stock or near stock modulars quit making power at 5700-5800 & the typical person puts 4.10's in then goes to the to the track with a stock car with 26" tall tires & is almost always disappointed with the times/etc due to their inabilty to keep the rpms in check. for a car that sees the track more than once 3.73's are a better choice.
as to the rear axle, I agree that it should be built reguardless but especially with a stick & d/r's as a stock car in that situation car break spider gears with the right (or wrong depending on how you look at it) launch.
as to your situation with the 13.44, thats after gears & cams I guess by your statement so how is that not helping my statement? not to knock you or your car but I'd expect a little more from gears & cams than a 13.44.

[OH03GT]

Originally Posted by casper gt the reason I say that 4.10s in a stick car at the track are a "rookie mistake" is that are for the rpm issues that I mentioned, stock or near stock modulars quit making power at 5700-5800 & the typical person puts 4.10's in then goes to the to the track with a stock car with 26" tall tires & is almost always disappointed with the times/etc due to their inabilty to keep the rpms in check. for a car that sees the track more than once 3.73's are a better choice. as to the rear axle, I agree that it should be built reguardless but especially with a stick & d/r's as a stock car in that situation car break spider gears with the right (or wrong depending on how you look at it) launch. as to your situation with the 13.44, thats after gears & cams I guess by your statement so how is that not helping my statement? not to knock you or your car but I'd expect a little more from gears & cams than a 13.44.

great points indeed and very understandable!

the reason for the 13.44 - that video is my very first run on that setup. the motor build, clutch, new shifter, 28" tall slicks and 4.10s. I had not been able to get to the track and dial this new set up in because of troubles with the build and money issues. Last year - normally - on just the "basically" stock motor (cai and canned diablo tune) 26" tall Drag Radials, and stock 3.27s, i would launch at 4000-4100 rpms and run a 13.7xx all day long.

This run in the video i launched at 4200rpms just to get a feel for it. If you watch that launch in the video, it bogged horribly off the line. Yet it ran faster than it ever did last year. Was i surprised that it wasnt quicker than a 13.44, not really becuase of the launch. Was i surprised that it was faster than last year, not really i was kinda aiming for that lol. My final run that day i had raised the 2step to 5500rpms for the launch and ultimately snapping an axle (stock axle) and never gettin to see what the potential was for this car.

I do realize jumping up 1300 rpms was stupid but i was impatient and ready to see what she could do. in doing so that ended up being the last run of this year. I have my car back together with better axles and diff. but am too worried about breaking somthing else. so its gonna have to wait till next spring to see the full potential. chassis and axle bracing will be in the works during winter time.