373 replies to this topic

[RWP80000]

Jim,

 

Good input, this is where "on paper" meets the real world.  I had a 2003 with 6 speed that was strictly street driven and never liked the drivetrain package feel but I attributed it to the 3.9 final gearing.  Didn't notice any shifting issues but again it was as daily driver. 

[pat slattery]

Would a smaller tire and wheel , say a 14 inch make much of a difference in the overall gear ratio, and not sure if any difference in the handling.  Just throwing out suggestions, not sure what would happen

[Ron Alan]

Everyone in the street crowd thinks they want a 6 speed "upgrade"...until they do it and find out what a pain in the ass it is! plus they are hard to find and expensive...and apparently they arent very reliable. Knew of one miata driver that had the same experience Jim did...went back to 5 speed!

 

10-1!

[Alberto]

One STRONG down side is that trans is a @#$$%^&!  I built one for my STL car and took it out after 1-2 sessions as I could not race it at all and installed an Sm 5 spd. I thought I left the engine on the track at least 10-15 times in 2 sessions as the gates are so close.. often 1-3-5 was complete guess.. same for 2-4-6..  Maybe those who drive in street cars can comment.. but I would guarantee 4-5x more missed shifts than with the 5 speed

Jim

 

+1 terrible shifting trans compared to the 5 speed.  My '04 MSM had it.  I don't think I would want it in the SM.  Expensive too.

[Johnny D]

We talked about different diff's, how hard is it to swap gears in the trans to a different ratio ?

J~

[Bench Racer]

[Tom Sager]

Would a smaller tire and wheel , say a 14 inch make much of a difference in the overall gear ratio, and not sure if any difference in the handling.  Just throwing out suggestions, not sure what would happen

Very roughly speaking about 4% change in gearing and about the same reduction in contact patch size.  

[Mark McCallister]

Interesting discussion on ducts pulling from the cowl area here: http://forum.miata.n...ad.php?t=456636

[Sacslider]

I spoke with one person here on the left coast that was going to do that very thing out of his pocket.

 

But with the rule change or in flux he's totally not going to do it now.

J~

 

J~

 

You are absolutely correct, That person will not be investing that money as he previously planned to try to find help for the 1.6.  In light of the current atmosphere that money will be otherwise invested in other ventures.

[Bench Racer]

Please don't take this post wrong, I'm all for flipping some bones to the 1.6. And don't anyone start talking any 99 pieces unless it's the 99 engine.

 

When a fully preped Miata ITA 1.6 car shows up at a track near you, what are the lap times compared to the fast Spec Miata times?

 

Fully preped Miata ITA car, were talking shocks, springs, bars, ITA pro motor (compression ratio 9.4:1), Mega Squirt, header, diff gear, tires and on and on. Oh, and the driver is no slouch.

Example to me is, a very capabile driver in a well preped car at Blackhawk Farm can not equal the Majors level Spec Miata lap time. Together with Voytek (SM) they put on one hell of a race to watch.

Posted this ^ several pages ago, no one bit. The ITA class can implement a bunch more than the Spec Miata class. At two thirds (4 out of 6) of the CenDiv tracks the ITA car is slower than the Spec Miata. Please post your division track records and then let's talk about what to get the Miata 1.6 to racing with the Miata 99 plus cars

 

Trust me, at ABJ South, Blackhawk, Miw Mile and Road America there have been well preped and driven Miata ITA cars that haven't to date been faster than the Spec Miata. They are allowed and do implement many of the ITA allowances well beyond the Spec Miata allowances.

 

Close only works in hand gerenades and horse shoes. 

 

Drop a 99 enginge in a 1.6 chassis, done deal, the torque will be there. 

[38bfast]

For the SMAC to recommend changes to the 1.6 it would need data to support those changes. As an example, if requesting a header they would need performance data before and after the change from a reputable source. 

[Mark Lenney]

Posted this ^ several pages ago, no one bit. The ITA class can implement a bunch more than the Spec Miata class. At two thirds (4 out of 6) of the CenDiv tracks the ITA car is slower than the Spec Miata. Please post your division track records and then let's talk about what to get the Miata 1.6 to racing with the Miata 99 plus cars

 

Trust me, at ABJ South, Blackhawk, Miw Mile and Road America there have been well preped and driven Miata ITA cars that haven't to date been faster than the Spec Miata. They are allowed and do implement many of the ITA allowances well beyond the Spec Miata allowances.

 

Close only works in hand gerenades and horse shoes. 

 

Drop a 99 enginge in a 1.6 chassis, done deal, the torque will be there. 

 

 

Bench,

 

Were the SM you speak here actual SM, or the class of car that was DQ'd at the runoffs?

[Steve Scheifler]

ITA, should be faster than SM of the ssme year, period. So what are you trying to suggest, that a '99+ SM is faster than a full-on NA ITA car, and by extension obviously faster than NA SM?

The problem is that I question how many ITA Miatas are top-prep and driven to their potential. We have rarely run against any that we didn't beat easily in our 1.6 SMs, including at all the tracks you listed.

[Tom Sager]

ITA, should be faster than SM of the ssme year, period. So what are you trying to suggest, that a '99+ SM is faster than a full-on NA ITA car, and by extension obviously faster than NA SM?

The problem is that I question how many ITA Miatas are top-prep and driven to their potential. We have rarely run against any that we didn't beat easily in our 1.6 SMs, including at all the tracks you listed.

1.6  ITA Miata runs at 2255 pounds and with ITA rules should be quite a bit faster than any SM of any year as you suggest.  The '94-'97 Miata runs ITA at 2460 pounds which makes that car a slug.  There just isn't any love for the '94-'97 anywhere except maybe FP.  

[ner88]

Isnt the 94-97 EP?

[Tom Sager]

Isnt the 94-97 EP?

Yes you are correct.  

[SaulSpeedwell]

'Saul', what are your thoughts about ducting an airbox/insulator to the left base of the windshield? A 'cowl-induction' so to speak.

 

I like using data to guide decisions, and my only question would be whether there is truly cold, high pressure, air there.  There SHOULD be. 

 

On the '99, I tested for inlet pressure to figure out the fender liner thing by using simple Dwyer Magnehelics (like a manometer but with a dial gauge, you can get them on eBay all day long for $40 - you want one that is scaled for 0-1" or 0-2" of water).   IAT came from OBD-2, but the 1.6 would need dedicated data acquisition, even if it was just 3 thermocouples and 3 voltmeters. 

 

Ironically, I met a a friend and fellow engineer from MI last night, who is new to racing with a 1.6 (Matt Johnson's old car), and it turns out he has IAT instrumented.  With the typical "straight metal intake", he said he was seeing 60 DEGREES OVER AMBIENT in his 1.6!  That's in Michigan.  That is easily double what my experience and data with the 99 was.  He has said he could send me the data, but I literally don't have a dog in this hunt and I have a backlog of other things to do.

 

If someone from the SMAC or the 1.6 Owner's Union would like the data, I can help put you in touch with him.  If I had a 1.6, I would be asking for a provision for a "cold air intake".  I believe it will add a little power, solve the "laying down" problem, and then you can get back to making weight/plate parity adjustments.  I'd love to "add torque" to the 1.6, but I don't see how to do it cheaply or easily. 

 

Back in the Regionals-Only days, someone out NORPAC/West Coast way supposedly ran an intake past a narrow radiator and right into the mouth of the car.  I think it was protested, deemed a no-no, and that's when the radiator rule got changed.  I was about to do the same thing myself when I heard the "bad news".

 

On the other hand, if $peedy McFrontrunner wanted to, I believe he could already make a "cold air intake" within the existing rules.  Bend some intercooler-type pipe and get it down and out of the engine bay into a direct line of cold air somewhere.

 

Sounds like a good project for this alleged Buras/Drago 1.6 effort

[SaulSpeedwell]

We talked about different diff's, how hard is it to swap gears in the trans to a different ratio ?

J~

 

Difficult, pricey, and subject to dwindling parts. The RX transmissions are shorter-geared than Miatas in every gear but 5th.  A good idea in theory, but not practical in reality, in my opinion.

 

Changing diff gears is as easy as a $1000+ of labor and gears, as there are 4.44, 4.62, and 4.77 available for the 1.8 diff, but nothing helpful for the 1.6 carrier that I know of.  The Miata 4.3 is the shortest "stock" ratio for the 1.6 carrier that I know of.  Also not a practical idea, in my opinion.

 

The 4.77s are the bee's knees/cat's pajamas at some tracks, for Miatas in classes where they are legal.

[SaulSpeedwell]

For the SMAC to recommend changes to the 1.6 it would need data to support those changes. As an example, if requesting a header they would need performance data before and after the change from a reputable source. 

 

FWIW, my experience with 1.6 headers, whether stock, hogged-out stock, or aftermarket, is the good ones only help at high flow (i.e. 116HP+ motors, and only at VERY high revs ... like 6500RPM+). 

[Bench Racer]

Bench,

 

Were the SM you speak here actual SM, or the class of car that was DQ'd at the runoffs?

Mark, do not have an answer to your question ^.

ITA, should be faster than SM of the ssme year, period. So what are you trying to suggest, that a '99+ SM is faster than a full-on NA ITA car, and by extension obviously faster than NA SM?

The problem is that I question how many ITA Miatas are top-prep and driven to their potential. We have rarely run against any that we didn't beat easily in our 1.6 SMs, including at all the tracks you listed.

 

1.6  ITA Miata runs at 2255 pounds and with ITA rules should be quite a bit faster than any SM of any year as you suggest.  The '94-'97 Miata runs ITA at 2460 pounds which makes that car a slug.  There just isn't any love for the '94-'97 anywhere except maybe FP.  

Steve and Tom, you both know the ITA driver I'm referencing with a full out ITA 1.6 Miata that I described in an earlier post. At Road America and at Blackhawk Farm, his car can not equal or better either Spec Miata track record. At the ARRC this year the car could not equal or better the Spec Miata times. The car is pro preped. I believe the driver still holds the F production track record at Road Atlanta. Not busting the drivers balls, that's not the point of conversation. When he in his ITA Miata and Voytek (in whatever Spec Miata) at Blackhawk Farm have at it, it's fun to watch. No one runs away from the other. My point of conversation is, finding the pound foot of torque required for the1.6 to play heads up from 4,000 rpm on up with the 99 plus Miatas is a real issue.  On the comment I made about the Spec Miata having a faster record at 4 out of 6 CenDiv tracks, there are some years between the ITA records and the Spec Miata records.

 

This is not a, I'm right thing and everything else in the racing world is screwed up. Road Atlanta, ITA Miata (year recall 1.6?) Price 1.40:741 2010, Spec Miata ( year recall1.6 ?) Aterbury 1.42:716. 2 seconds, that's big. Were both of these records set tech free.

 

I have implemented an ambient air system for my 1.6 and july of this year, temp at filter never went over 90*. Don't remember what ambient temp was. Steve, you did some stuff checking temps. I do remember one day at Road America when this blue Spec Miata came down the front straight with the drivers head light cover flapping up and down, to which I said to myself, naw, that can't be part of a implemented plan.