NASA ST6 Build

GENERAL At The Track
1

I’m new to the board, so this is my 1st post here. My brother and I run in NASA Great Lakes, and have been in the region since 2015, obtaining regional championships in the now old TTE in 2016 and 2017. Since the Miata is a daily driver car, we were looking at getting into Spec Miata, but stumbled across a caged 1991 Integra GS for sale for a good deal, so we jumped on it to put it in NASA PTE, which has since changed to ST6, so it changed our plans a bit.

A bit of history on the car, is that the owners had the car as a daily driver in Texas, then in 2004, decided to cage the car and set it up for a modest SCCA ITA build, and NASA Honda Challenge 4, where it competed for 3 years, and then had a sparsely tracked period in HPDE and TTE in Texas. Then the owner moved to Michigan, and obtained a different track car, placing the Integra for sale.

Needless to say, we bought the car, but with years of time trialing, it requires numerous investments in safety updates and modifications.

Purchased with:
Cage installed…kind of
Drive Shaft Shop Axles
Kill Switch
ABS delete minus ABS brake booster
Koni Yellows on H&R race springs
DC sports header
Hondata piggyback on 94 Integra ECU/Distributor.
Progress Rear Anti Sway Bar

Now the car SUPPOSEDLY dynoed at 134 or 143 peak hp at an unknown weight. We competed against the car one time at a NASA event in 2016, where the car ran 1:49s on R888s, and the driver’s 1st time on the track.

So the build begins…

This car is PRIMARILY being built for ST6, but will still be compatible with being classed in Honda Challenge 2. Major issues involve updating the seat, nets, harness, extinguisher, and for whatever reason, the original cage builder, built the cage illegally(by today’s standards), by having a non-straight diagonal in the main hoop). We have a friend that can cut and weld in a legal revision to the main hoop to make it good to go.

Now, the other part of the process is understanding what we have to work with. Weight is unknown, so I had to make the single largest racing purchase with getting a set of used racing scales, which indicated that the car, with no driver, passenger seat still in, and 1/5th tank of gas resulted in a weight of 2285lbs. Lighter than I expected. The race weight is still to be determined. By rule, HC2 should be immensely faster than ST6, but lap times and records tend to prove otherwise. ST6 will likely be in the 1:40s on Mid Ohio’s pro course, where as HC2’s track record was in the 1:38s. Carrying the max of ballast of 250lbs in ST6, means that we could remove 250lbs to go to ST6, hypothetically with no other changes. 250lbs in our 2185lb(with driver) and 116ish RWHP Miata is EASILY 2.5 seconds at Mid Ohio. It’s hard to say if the same will prove true with this Integra platform.

First things first though is the car has to be competitive enough to get into the 1:40s(or faster) at Mid Ohio to compete at NASA National Championships this year. This car is still a LONG way off, and we are the poorest people in racing(literally). We will miss the opening event at NCM Raceway at the end of the month, but hope to at least do time trial at Mid Ohio at least to test the car’s baseline out.

ST6 is a raw power:weight ratio of 18:1 with modifiers, so there are numerous options for power:weight choices that are to be determined.

Performance options to be added:
-Mishimoto Dual Row Radiator(facebook marketplace special)
-Koni Yellow rebuild/race revalve at TruChoice with a TBD linear spring rates
-Battery Relocation to passenger footwell with DEKA ETX20
-Window Weld in OEM engine mounts
-Add OEM non-ABS brake booster
-Add adjustable brake proportioning valve
-Gut hood and tailgate to the most while still being structurally integral.
-Add Lexan to windows
-Possible PLM Toda header
-Possible custom intake
-4.9 or 5.1 final drive
-possible different 5th gear
-Add LSD of some form
-Add 15x9 wheels with 225 hoosiers up front.

There are various other tidbits, but it should be interesting. This a totally new, foreign world to me compared to the Miata, so hopefully it works out.

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2

That’s cool stuff! Want some G2IC stickers? I hear they add 2HP to the butt dyno.

3

Lol perhaps, although in honor of one of my brother’s spec miata friends that died recently, he is running a different number this year. I guess he wants to run green livery with the black, although I’m a fan of red and black personally. It will start out as being blacked out. I will say this car is much more difficult to work on than my Civic VX and the miata. The headlights took about 6 hours to remove due to that bottom bracket. Luckily they are not going back in, and I am making faux lights to take weight out of the nose.

4

The car came with 15x8 Buddy club wheels with 225/45 R888s, which are still slightly narrower than the 205 Hoosiers, but we have much lighter 15x8 Advanti Storms, although we may need 15x9s up front.

5

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6

Got a new in box mishimoto for $80 on craigslist. :slight_smile: headlights were designed by some real asshole engineers, but I got them out. Power steering is coming out and getting replaced with a Dev Sport power steering delete kit, and I bought a Deka ETX20 battery that I’m going to relocate inside the cabin.
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7

If I am not mistaken I nearly pulled the trigger on this car when it was still in Texas. Wide wheels. I run the advanti on mine as well. Look forward to seeing more race car stuff.

8

May have been. Old owner was Stuart Hembree and he ran in NASA texas region I believe. Seems like he did events at TWS and MSR, amongst a few other places. We will likely lighten this car quite a bit then add the max of 250lbs of ballast…and maybe faux ballast, to make it more of a power car for racing purposes.

the most annoying part is being penalized for having adjustablre ball joints and adjustable rear upper control arm, so I have some factory arms I have to put on to get back 0.2 modifier points back.

2450-2549lbs: 18.0:1 P:W ratio=136-142hp…AVERAGE hp…not peak, so peak power would probably be 140ish-146ish.

Heavier still would be:
2550-2649lbs: 17:9:1 P:W ratio=142-148 avg hp, so about 146ish-153ish peak hp. Of course at that point, I could just go 2650lbs and be 17.8:1 and go 1 more hp.

kind of leaning to the 2550-2600ish mark as I could run the car at near peak honda challenge 2 hp(150hp), but be way overweight for HC2…which would be somewhat fixed by removing 250lbs of ballast, although I highly doubt we get a DA integra down to the 2200lb min weight WITH the driver for HC2, however the Mid Ohio track record in HC2 is only 1:38.9, so even being underprepared, the car should be near or surpass that time even if it is technically 150ish lbs overweight, but hard to say since HC2 is on slower Toyo RRs and much narrower 7" wheels. We have done a billion events, so we know 10lbs of weight in an underpowered, but light miata is worth .10-.12 seconds at Mid Ohio. 250lbs would be like 3 seconds/lap…in the miata. This will be a heavier and powerful car, so hypothetically less sensitive to weight changes, but we shall see. Fast ST6 cars will likely be in 1:40s…probably even less. I know if we built our Miata to ST6 rules, it would definitely be sub 1:40.

I get the feeling ST6 will eventually set times faster than PTE, despite ST6 having a raw P:W of 18:1 compared to PTE’s 16.5:1, which is what Huffman ran from here. The rules have a lot of holes and questions so I have to clarify with Greg Greenbaum as to what is and is not allowed.

some of my other questions are if traction bars are allowed as it would save an enormous amount of weight and space from the front end, and likely perform better. It is not well stated in the rules.

9

Yeah that was it then. TWS was home turf. RIP
looking at ST4 myself.

10

one of stu’s vids.

ST4 has really taken off. ST5 is lacking, but I know quite a few PTE guys going ST5. PTE wasn’t popular nationally, but in our Great Lakes region, it was the biggest and most successful class, with contingency nearly every weekend. I’m not a fan of ST6 rules, but it’s basically what we are left with, so we are going to send it. I think we will still have a solid field of cars.

ST4 would be interesting in a DA. Totally different build set to compete at the national level. I wouldn’t even begin to comprehend where to start with that one, but it would have to be similar to Ruck’s FP Integra with more power or forced induction/swapped. At the national level it’s pretty damn quick. Way out of our budget lol.

Here was the daily driver TTE miata we have that we drive to the tracks. This session was hilarious, because we had run Pitt Race before where most others had not, so they were learning the track but we wanted a good grid spot determined by warm up times. Excuse the unsmooth driving and understeer, as the car was a whole new setup that got better.

11

What LSD options are you considering? I don’t think there are many.

12

Quite honestly, I have clue as of right now. B18 cable trans are incredibly confusing and have a surprisingly bare market. That and I believe the 90-91 have a 4.4 final drive and different splines compared to the 92-93 trans with 4.26 final drive or am I wrong. Are the 92-93 trans interchangeable with 90-91?

I know Ruck uses a Kaaz LSD on his FP Integra, but I’m not even sure we can afford an LSD, even if one exists. We will likely run a 4.9 or 5.1 final drive which also seems to be a pain to find for this transmission specifically. To counteract for a lack of LSD, I’m just going to run stiff rates…thinking 1200 rear, 1000 front.

13

The 92-93 trans runs the larger input shaft like the 94-01 Integras so you can swap the internals with a wide range of gear sets, but you could run a 90-91 trans if you use a clutch for that age range and make sure you use the right pilot bearing.

14

Well our car is a 91 with the S1 trans. Can the 92-93 YS1 trans swap on directly? If so the YS1 has a 5.1 final drive available and more LSD choices.

15

https://m.youtube.com/watch?feature=youtu.be&v=Zobt7OP_aRw

16

Congratulations! tire money!

17

Thanks. We run hoosiers so it’s mostly just tires, and not so much on the money side. The car has had quite a but changed since we bought it last year. It still needs a different final drive, suspension tuning, ECU tuning, possibly different header, lots of bushings replaced, and working with the CoG. the biggest pain has been it still popping out of 3rd gear, which I suspect is due to chassis flex, so I’m going to add a 3 way strut bar to stiffen up the front of the chassis.