177 replies to this topic

[Jamz14]

All, I have said my piece. It is apparent that todd and others have 1.6 fatique and I have no interest in going through this for the next 4 years. I'll let others more qualified deal with it.

[Jamz14]

Peace. Fing auto correct

[Jim Drago]

Todd, I get it. Your response is no different than the first one. I'm asking you how to modify the cross without dicking with the perches or moving weight around in a legal fashion? How to do it without messing with other things that you don't want to do like bar preloads? Help a brother out instead of remaining cagey on the subject.

Jamz

You will have to dick with the perches set the preload on bars.. But many if not most are doing that regularly. The end result will be a more b alanced car with the extra ballast in pass floor. 

If you do nothing but drop 50 lbs in pass floor an d change nothing.. I bet your cross wont change more than .3.  

[LarryKing]

Jamz, as it was explained to me, think of the suspension as a four-legged stool. To change cross you raise one set of opposite corners (LF & RR, for example) and lower the other opposite corners (in this case RF & LR) an equal amount, ie, 1/4 turn up one cross and a 1/4 turn down the other cross. Ride height remains the same, and it's amazing how much change a 1/4 turn makes.

[Jamz14]

Guys, I understand manipulation of the perches to change cross. That's what I meant by ride height. Changing the corners to achieve my target.

Walter, I might be wrong but I don't think that is correct. If I change a corner perch the level of the platform should change.

Ride height was probably not the best term to use on my part. I'm talking about a level platform.

Jim, preloading the bars doesn't sound like a good idea. Every time I accidently had preloads in the bars the cars behavior was off. I doubt I have the skill to effectively use pteloading advantageously.

[Jamz14]

To be clear. My car is scaled and balanced every race weekend. The concepts you ate talking about are far from foreign to me.

[LarryKing]

I don't know what you mean by level platform.

[Tom Sager]

I don't think you will see a single car increase in the number of builds.

I believe this change will coax some cars out of semi-retirement and also believe some will be built.  A plus for the NA1.8 in my experience is that it is a more consistent power plant compared to a 1.6 (easier to  tune on race day) and suffers from fewer electrical gremlins compared to the NB cars.  Donors are cheap and easy to find as are donor engines. I've only raced my '95 which is strong and fresh in only 1 meaningful event over the past 2 season.  With this change I'll give it a rip for probably half of next season and see how it goes.  Jim's posts on the relative power change (with and without plate) and also compared to a '99 are nearly identical to what I've seen comparing my cars. 

 

I think it's fair to question what is a meaningful weight penalty (50 pounds) in exchange for no plate rather than a larger plate with zero or little weight change as the combination of 50 more pounds and the older front suspension geometry probably puts the car at slight handling disadvantage compared to the other cars with the hope that the extra power overcomes that plus a bit more.  Sorry, that sentence is a mouth full. 

 

With the cars being pretty darned close even before the proposed change, not much is needed. For longer tracks the proposed 2017 rules should make the car a bit quicker.  On the shorter tracks or tracks where the cornering time per lap is greater, it may be a wash at best.  All this will be better confirmed on the track among hopefully a few more cars.

 

People can submit to either sanctioning body and make their case. 

[Ron Alan]

Rob, my legal weight is 2350. Your poSt brings up a good point though. If your weight in a 95 is 2325 and mine in a 97 is 2350, why the difference? Obd1 and 2 differences? If it was thought that a difference was needed back when these weights were set at there current level, what changed in the new accessments?

James, James, James...there is no difference now. Rob was saying if we kept the current RP and lost 25lbs he would never make weight...

 

Time will tell if the new proposed rule change when it becomes law will improve the car! I will keep my fingers crossed...but I will enjoy not bringing tools to tech!

 

Thanks for agreeing with me Jim that Danny did not represent a good argument. I'm pretty sure I know what my 99 makes restricted and what my 95 will make unrestricted. 

[Jamz14]

Ron , Rob,

Ahh. I didn't put together that was what rob was saying. Thanks.

Guys, maybe I am being simple but....... I can't understand why it is thought that the correct approach for helping a car that is thought to be only slightly off is to give it over the top help ( no rp) , and then take 3/4 of it back (50 lbs!). Why not just give it a little without the need of dialing back much of what you just gave it?

Just give it small incremental improvements until you get it right. Why the need for complex alchemy?

[Jamz14]

I don't know what you mean by level platform.

A flat car with all four corners at the same height. Tune from there. Instead of a car with the corners all over the place. It is very very easy to have the cross perfect. I can do it with only adjusting one spring if I wanted to. But then that corner is a mess.

It was my belief that todd was suggesting that there are other ways of getting your cross without adjusting the spring height. And there are. I can move around items that I'm allowed to like the cool suit box. I can preload the bars. I think I could impact with tire pressure if I wanted to. Etc.... But is todd saying that I am missing another way that is more functional and doesn't have negative knock on effects?

[Jim Drago]

Jim, preloading the bars doesn't sound like a good idea. Every time I accidently had preloads in the bars the cars behavior was off. I doubt I have the skill to effectively use pteloading advantageously.

set the preload.. meaning dial out any preload you induced when moving perches

[Bench Racer]

With NA 1.8 weight comments made within this thread, what is a minimum weight without driver one can build said car?

 

1990 NA 2000 lb.

NA 1.8    ???? lb.

1999       2100 lb. 

[Tom Sager]

With NA 1.8 weight comments made within this thread, what is a minimum weight without driver one can build said car?

 

1990 NA 2000 lb.

NA 1.8    ???? lb.

1999       2100 lb. 

NA1.8 about 2075 empty no driver, no cool suit and only a light fire system.   Maybe a bit lighter if you really work at it.   

[Diller]

I am actually happy about the changes. I have been running a 94 for 2 years now and am getting the driver and car prep to the level where I can see the differences in the generations. 

 

This adjustment will affect the "horses for courses". I felt that the only track that the NA1.8 showed it's stepchild strengths was Barber. Less weight than the NBs and more torque than the 1.6. I felt the car came off the corners better than the 1.6 and could carry more entry speed than the NBs. Every other track I run at has favored the NB or 1.6. I think this adjustment will make it more competitive at tracks like VIR and Road Atlanta where 50 pounds isn't going to feel as much as it is but the HP should bring things closer to the NBs. I think it will hurt at tracks like NCM, Barber, and CMP where the weight will absolutely be a felt. 

 

My crystal ball tells me that we will eventually drop back to 2375# and that will be the sweet spot but I am very happy the SMAC has taken a look at the bastard children of SM and put forth an effort to help. I will have healthy motor and well setup chassis to start 2017 and look forward to the results.

[MPR22]

Guys, I understand manipulation of the perches to change cross. That's what I meant by ride height. Changing the corners to achieve my target.

Walter, I might be wrong but I don't think that is correct. If I change a corner perch the level of the platform should change.

Ride height was probably not the best term to use on my part. I'm talking about a level platform.

Jim, preloading the bars doesn't sound like a good idea. Every time I accidently had preloads in the bars the cars behavior was off. I doubt I have the skill to effectively use pteloading advantageously.

James, 

 

Walter was mostly correct.  You level the car then adjust the corners as he described. With the difference in spring rates you may not use a 1/1 turn on each corner.  With more ballast you will have a much corners that are much closer to 50/50 than if you had less ballast.  Essentially the car would be much more level because you would be making small adjustments at each perch to offset the extra weight of the driver.  Chris' in the 99 can achieve a completely level car with 120+ lbs of ballast and 50/50 cross on a completely level platform.  Weight is your friend if you are looking for a more level car.  

 

My guess behind the reasoning behind the open plate is to maximize HP and then if they have to remove weight they can.  The other way the would keep changing restrictors to get a balance.  Remove one of the variables completely and then tweak the only remaining variable.  As to the question about OBDI and OBDII models I suspect the 97 will like the change and be more usable because it has a smarter computer.  

 

I have raced 3 top prep NA 1.8s with 3 three top drivers in the 2012 trim.  They suffered tremendously on the top end in fourth gear compared to the 99.  Everywhere else there we as good or better.  Get in your car and race it then give feedback, don't start complaining before you have even tried the fix.  

 

If the SMAC/CRB decides they haven't gone far enough they can fastrack a change and in 3 minutes you can pull 20-20 lbs of ballast without much change to your cross, maybe .1 to .2.   

[Jamz14]

All,

I have been using bad terminology to describe the same things you guys are describing. I don't set my ride height from the pinch welds. I measure the bump stop travel distance and that is what I meant by level. Meaning equal travel distance and whatever the actual chassis height is whatever it is. That is what I mean by level. Equal is a better term. Sorry for the confusion.

[Jamz14]

Mpr22,

Thank you, good advice. You are always patient with me and I appreciate that.

I still don't want additional weight and prefer handling over power.

I still would rather we had more cold air into the intake than no restrictor plate. I guess we could have just gone to a 49 or 50 mm plate but probably enterprise doesn't make one. If true, it seemed like a lazy approach to scrap the plate and overpower the car and then compensate by adversely affecting the handling. I get more fun driving fast in corners than being fast down a straight. If I wanted straight fun without any driving skill I would be racing corvettes.

[MPR22]

It was smart not lazy.  They made a 2 variable permutation into a 1 variable permutation.  They can more quickly find equilibrium by removing one variable.  Also it was the smarter way deal with the two ecus because with factory flows now they operate properly  ECUs don't like restricted air flows. They blew up a lot of Mustangs a couple of years ago restricting them in PWC races.  50 lbs is significant but not the end of the world.  

[Bench Racer]

. Why not leave the restrictor, give us the marker light and lighten us closer to the 1.6?

A few years ago Saul Speedwell posted on track test info about the different spec lines and ambient air intake from OEM air box positions. Maybe pm Saul and he might be able to direct you to that post or offer some info for NA 1.8 air intake.