Rx7TyreBurna

iTrader: (1)

I will mostly be AutoX'ing and might consider SCCA in the future.

I am not sure on which motor setup to go with.
I do have a full Megasquirt system that i'd like to make use of.

What I am looking for is more level torque. I never liked coming out of a corner, having no power at all, until high RPM, then needing to shift.

I was wondering what motor would be the best?

I considered turbo, but I think that might just add to the "turbo lag" issue.

I have also looked at a P-port N/A. But it looks like most people are going carbs for this, and ITB?

There is also the supercharger option, but it doesn't look like there are a lot of good options for this. I would love a twin screw, lysholm, supercharger. Whipple makes some good ones, and I know there would be a lot of fabrication required.

This will be a possibly 2 year build. Just looking at options.

Goal is responsive, and light. Not looking to make insane horsepower, but instead be able to come out of a corner like crazy.

This car will be pure track. It does not need to retain any street-ability.

Kentetsu

Read and understand the rules, then decide which class you want to run in. Build accordingly.

You didn't state what you are working with (what year).


.

Josh18_2k

iTrader: (3)

if you want to keep your interior, go SM. Yes, you can do SM, if you have a back seat. I don't know why no one does.. If you're willing to gut it, FP is probably the way to go.

I'd say do a high compression (NA rotor) motor with smallish turbo. plenty of ppl autox with boosted 4 cylinders, its not he end of the world. 300whp should be just fine for a while, until you get really competitive.

eage8

iTrader: (9)

SM is genius... I never thought of that before...

you can take your back seats out in SM so you actually don't even need them.

I'm not sure if you can legally run rear bins, but that's just that much more weight you can take out. not like they weigh much though.

my turboII would probably be SM legal...

Rx7TyreBurna

iTrader: (1)

Thanks guys!

Sorry, I had car in my sig, but I didn't post in the body of the message.

1988.

I am going all out. Gutted interior, fuel cell, roll bars, etc.

Pure track. Idle at 2k is fine.. hahah.

For a high compression N/A w/ a small turbo.... Do you mean putting some 9.7:1 in a T2 block and then small turbo? If so, do you have any suggestions to a turbo? GT25? Or smaller?

Currently, I have a 6-port N/A heavily modified. S5 Intake w/ VDI, etc. Electronic aux. I don't mind getting a T2 motor, and I think it might be easier to add the turbo to it.

Josh18_2k

iTrader: (3)

I don't know rotaries, I just know hat High comp spools turbos much faster. Heat isn't nearly as much of an issue vs track, so I would imagine an NA rotor boosted motor would be fine. Best talk to ppl who have built them tho. You cam be fast with typical turbo lag, just gotta throttle in a little earlier

Since you wanna go full race, check out FP. If that's too restrictive for you, you're stuck in XP. Don't even bother with EM, that's just dumb

Rx7TyreBurna

iTrader: (1)

Thanks Josh.
What is FP? And is the information on the SCCA website?
Or is that an autocross class?
In autocross, I used to run modified sports C. I think it was modified sports C... Been a while.

I'll look into a boosted N/A. I do have a few turbo's laying around. I have one from my WRX, but I think it might be too small.

I appreciate all the input guys. Been having fun getting car prepped. Darn sound deadening material is a pain to get off. Dry ice + hammer + time. LoL.

eage8

iTrader: (9)

FP is F Prepared, an autocross class.

modified sports C isn't an SCCA class... at least not recently.

Here is the scca rule book:
http://www.scca.com/assets/2012_Solo...ry_reduced.pdf

rapidriver

iTrader: (2)

I have gutted two RX-7s and tried every possible trick for getting off the sound deadener. Dry ice is the way to go but found that it works best in pellet form. I filled a kitchen garbage bag (doubled) half way with the pellets. This allowed for freezing about 4 sq ft at a time when laid flat. With a light tap tap I was getting some pieces to come off in 1-2 sq ft chunks. All other methods I tried I was lucky to get pieces more than a couple sq inches. For the residue there are probably many solvents that will dissolve this. I found that kerosine on a rag worked pretty good but because of the fumes, switched to rubbing alcohol and extra fine steel wool. And when you're done... bio freeze for the elbow.

Rx7TyreBurna

iTrader: (1)

Thanks guys!

eage8, the modified sports c was in my local car club. Bremerton Sports car club.

jkstill

iTrader: (11)

The biggest bang for the buck on corner exit will be gearing. Put some 4.77 or 4.88 gears in the diff - that is one of top gofaster mods for rotaries in autox.

eage8

iTrader: (9)

It'll also put you right into Street mod or prepared...

Rx7TyreBurna

iTrader: (1)

I've been considering E85. Would this change my class any?

There is a lot of E85 stations around where I live, and have seen some great power coming from it. It also has some insane resistance to detonation.

NeoTuri

iTrader: (2)

E85 doesn't change anything. I'm working on a build for E85 so I can get a safer tune on 9.7:1 rotors.

Rx7TyreBurna

iTrader: (1)

Awesome!

That will make tuning a little easier.

MADDSLOW

iTrader: (11)

Where do you find a 4.88 final drive?

Rx7TyreBurna

iTrader: (1)

Maddslow:

86-95 Ring & Pinions, Bearings, and Seals

5.12 ..... hahah!