Looking for any and all advice on suiting a Turbo II Rx7

Exactly, we are talking a 1987 Mazda Rx7 Turbo. OR at least essentially the same shell blah blah blah.

Anyway, what i am looking for is any advice from people who have seen or better yet, have rallied this car. I want to know weak points, best methods for skid plating, and generally anything else that might be of good knowledge for myself. This way i can build the car properly and also start stocking up on spares.

I have searched here and Special Stage and really haven't found too much information to this particular car.

Thanks in advance

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~A.M.S.

"Some people are afraid of heights, not me. I'm afraid of widths"



Edited 1 time(s). Last edit at 11/08/2008 07:45PM by low impedance.

Go to my website. www.nocoastmotorsports.net
You might find something useful in the 'Technical Discussion' section of the website. Speaking of which, I need to add more stuff to that area. I haven't updated it in months.

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Grant Hughes

Having built and maintained the most successful RX-7 Turbo II in the country you should probably talk to me. This was the car I built for Dave Hintz back in 1999 and won multiple divisional Group 5 championships and also the 2002 SCCA National Group 5 championship. Rick Schmeling bought it in 2004 and won G5 a bunch of times and still has it.
The first thing I'm going to tell you is don't build a turbo RX-7. The amount of trouble and expense it takes to keep it from running too hot is not worth it when you can get all the power you need from a ported NA motor. Plus you won't have the turbo lag. It's definitely more expensive to run it turbo. Big aluminum racing radiator and bigger Mazda Motorsports oil cooler - nope, not enough cooling. Swiss cheesed the bumper and hood full of holes and added a radiator/oil cooler water sprayer and it was still marginal on hot days. The big issue is limiting boost. These cars use the stock exhaust to restrict the boost so if you open up the exhaust you will have more boost than is safe for the motor. Adding a good boost controller helps but even then it's a challenge. Forget using the stock turbo setup. They are expensive to replace and you will be replacing them often because they like to shit impellers frequently. We put a HKS exhaust manifold and a hybrid Garret TO4-E turbo on Dave Hintz's car and it was trouble free after that. Had to rebuild it once for Rick Schmeling. What wasn't trouble free was the exhaust. Because of the intense heat of the turbo rotary and the low ground clearance of the car the exhaust required constant maintenance. And lots of armour plating to keep from getting squished.
So you are much better off buying a nice street port or bridge port rotary engine that will last you for years of rallying. You would be money ahead.
Other than that contact me if you want, there are a host of other prep details specific to this car you need to know. I may able to dig up a few build photos, too. It's a good handling car, superior to the 1st gen. RX-7.

i think i have a scanned build manuel somewhere. Ill look for it!

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rally gods would turn in their graves if they ever knew Lada's were now part of EU rallying!!!

i should probably as have mentioned that i only plan on attending CHCA (colorado hill climb association) and the PPIHC event(s).

The altitude the events are at make low displacement or non forced induction cars suffer. I have taken one of my other Rx7's up Pikes Peak and it really couldn't get out of its own way past Devil's Playground. This is my reasoning for the turbo.

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~A.M.S.

"Some people are afraid of heights, not me. I'm afraid of widths"

low impedance Wrote:
-------------------------------------------------------
> i should probably as have mentioned that i only
> plan on attending CHCA (colorado hill climb
> association) and the PPIHC event(s).
>
> The altitude the events are at make low
> displacement or non forced induction cars suffer.
> I have taken one of my other Rx7's up Pikes Peak
> and it really couldn't get out of its own way past
> Devil's Playground. This is my reasoning for the
> turbo.

OK, then plan and budget for radiator and a HUGE oil cooler.
I did the install on Hintz car and while I push the RX7 cooler on any turbo 2,0 to 2,3 piston engine, Mazda's ide of a competition cooler was sumpin that made the RX7 stock cooler look weeenie indeed.

>
>
> ~A.M.S.
>
> "Some people are afraid of heights, not me. I'm
> afraid of widths"

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

the other idea i was entertaining was a Camden supercharger as opposed to the turbo.


As far as the oil cooling goes, im assuming Mazdaspeed is my source for the comp. oil cooler. Would it be possible to run two (or maybe more) larger aftermarket oil coolers?

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~A.M.S.

"Some people are afraid of heights, not me. I'm afraid of widths"

low impedance Wrote:
-------------------------------------------------------
> the other idea i was entertaining was a Camden
> supercharger as opposed to the turbo.
>
>
> As far as the oil cooling goes, im assuming
> Mazdaspeed is my source for the comp. oil cooler.
> Would it be possible to run two (or maybe more)
> larger aftermarket oil coolers?
>

Sure, it's possible to do just about anything.

If you're hillclimbing then I can see the need for the turbo but with the altitude you'll need to pay all the more attention to cooling. Water sprayers on all heat exchangers for sure. The biggest challenge will fitting all the radiators in the nose. You will want to ditch the stock intercooler that sits on top of the motor and use something bigger but where are you going to put it?

probably model the "v mount" setup that is commonly used for the rotary cars if i run the turbocharger and obviously then, an intercooler.

I believe the rules will allow me to run E-85 so if i run the supercharger i will be less concerned with heat (but the Camden doesn't allow for intercooling anyway).

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~A.M.S.

"Some people are afraid of heights, not me. I'm afraid of widths"

As Mike Whitman once said, "If it doesn't overheat at a CHCA event, it won't overheat at any rally." Just about every rally car out there runs water sprayers. Mine is borderline overheating by the end of every hill climb, but was perfectly fine at Rally Colorado.

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Grant Hughes

well i will have to employ any and all tricks for cooling then just keep an eye on things.

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~A.M.S.

"Some people are afraid of heights, not me. I'm afraid of widths"

would two of these be ample?

18x14, -10an fittings?

http://store.summitracing.com/partdetail.asp?autofilter=1&part=EAR-86000ERL&N=700+4294839034+4294888847+4294792875+4294792816+115&autoview=sku

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~A.M.S.

"Some people are afraid of heights, not me. I'm afraid of widths"

low impedance Wrote:
-------------------------------------------------------
> would two of these be ample?
>
> 18x14, -10an fittings?

1 might be but holy sheet, mang look at the price!
Try checking out ex-circle track coolers used.
>
>
>
> ~A.M.S.
>
> "Some people are afraid of heights, not me. I'm
> afraid of widths"

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

im trying to get an idea of the total surface area that might be the most effective. I dont want more than two coolers (too much chance for leaking) drop in pressure etc. I also dont want anything to do with barb fittings.

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~A.M.S.

"Some people are afraid of heights, not me. I'm afraid of widths"



Edited 1 time(s). Last edit at 11/10/2008 05:41PM by low impedance.

Why not buy the above listed car and start with that, I think it is $6,000. By the time you get the oil coolers you are 1/6 of the way there

I think (but do not know) that turbo would be better in this car at low air density because they can flow more air then most chargers and they work better at high RPM and 13B should be a high RPM motor.

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In the long run reality always wins.