Stephan's SLC Build Log

[Stephan E.]

Re: Stephan's SLC Build Threat

My thoughts on gear ratios.

First you will need to decide the final drive. This all really starts here. I would recommend a 3.3 - 3.5 final for a duel use 5 speed car. You could go a bit lower if you have a 6 speed. 3.2 maybe and set 6th as you freeway gear. Track only car will work best if you figure out the top speed you will need. I used 170mph for mine. You should ask other open track guys in you area or intended track or tracks what they would recommend. But 170 is very fast and most tracks just don't have those speeds. So I will assume a 3.44 final and a 28 inch tire as I proceed. Things are rounded here to make it simple. I will link a good gear calculator at the end.

1. Ff you intend to drive the car on the street and in traffic then 1st gear should be selected to start the car from a rest at traffic lights without a lot of clutch slipping drama. A lower gear here is also very useful for crawling around the paddock and getting on the trailer. 2.8 to 3.0 will work well here. Don't keep lower 1st's such as the 3.5s in the Audi's and the Porsches. Its worth it to change them in my opinion. I did and used a 2.8 for first.


2. If you intend to drive hours on the freeway. Pick a freeway speed, 75 is a good one for me, and a engine rev that suits the engine as well as other factors such as cabin noise, etc. Then select top gear, 5th or 6th, to work for you.

3. I have a 1.73 2nd and it is the go to gear under 70mph, abet still gobs of traction issue at anything near full power, (500hp in my SLC and about 350 in GT40)

4. 3rd and forth. First 4th gear should be 1 to 1 and will get you to about 140mph with a 6500 rev limit. On many tracks this will be your top gear. 3rd will, believe it or not, will be your down shift gear for slow corners for just about all the corners at most tracks unless the corners makes a 150 degree or more direction change. Really at most tracks you will do the whole day in 3rd and 4th and be just fine. Mine are 3rd 1.73 and forth .98 & 1 to 1.

So dual use car.

1st 2.7- 2.9
2nd 1.75
3rd 1.38
4th 1 to 1
5th Only .85 (this about 2900 @ 75mph)
5th with 6th .89 (this will be about 3k on revs at 75 mph)
6th .7 (big top speed number but would be a great cruise speed, noise, fuel number etc.)

http://www.tremec.com/calculadora.php

Hello Howard,

I do appreciate all the information you provided. There is sooo much to think about.

I purchased a Graziano V8 with the kit which is quite short. I considered it the more economical version down the road. The V10 was 3k more and still not that much longer geared. I thought the money is better spend on a drop gear set matching the motor characteristics when I know what I want. Also I have not decided if I'll track the car. My tires are 26.5" OD. I think the final drive in the V8 Graziano is around 3.44.

Cheer's

 

[Howard Jones]

Re: Stephan's SLC Build Threat

Here's a good tire size webpage. Lots of useful calculators.

TireSize.com - Compare Tire Sizes, Specs, Prices & more

 

[Alex]

Re: Stephan's SLC Build Threat

Thanks for the info,

I know those ITbs can be a nightmare. If I go ITB, my preference is with the Harrop Hurricane for all the good reasons you just listed even others look better. Lots of time to decide which transmission ratio and engine will be the chosen ones. Any input is welcome. I don't want to go through these experiences losing time and tons of money.

Cheers

I was using the Harrop and I was not satisfied.

In a full throttle all the time application I would have kept them, but for street driving, no.

I wasted a lot of $$$ on dyno time as we tried to get the idle under control and timing proper and we couldn't. When my tuner spoke w/ their tuner we were baffled at how they thought allowing the computer to pull 100% of the timing was "okay"

btw, every single LS Harrop owner I found on ls1tech had the exact same experience as I did.

 

[Stephan E.]

Re: Stephan's SLC Build Threat

I was using the Harrop and I was not satisfied.

In a full throttle all the time application I would have kept them, but for street driving, no.

I wasted a lot of $$$ on dyno time as we tried to get the idle under control and timing proper and we couldn't. When my tuner spoke w/ their tuner we were baffled at how they thought allowing the computer to pull 100% of the timing was "okay"

btw, every single LS Harrop owner I found on ls1tech had the exact same experience as I did.

Holy cow,

I am so glad you let me know that. That puts the ITB idea at the other end of the spectrum of choices. I also had an interesting call with a company offering drop gears for the Graziano. I am closing in on buying a set, that will eliminate the need for an ITB and a high revving engine anyway. The gear ratios are a dream for a V8 application with a 7K redline.

Again, thanks for the support!

 

[Mike Costello]

Re: Stephan's SLC Build Threat

Congrats on SL-C delivery, looking forward to another PA build! I've been building a GT-R with a buddy for last couple months just a few minutes from you in Furlong. Will have to meet up sometime.

 

[Stephan E.]

Re: Stephan's SLC Build Threat

Thank you Mike,

We will do that!

 

[Stephan E.]

Re: Stephan's SLC Build Threat

OK guys,

I am signing off on this thread since I misspelled the subject line.

threat = thread.

More news underway...

 

[Stephan E.]

Welcome back under a new subject line.

I was able to secure one of the Graziano V8 drop gears from Erik at In Line Racing. We did the math today and the changes are really better suited than the V10 gear ratio. The new ratio will be 1:0.76 and will provide a sweet ride during all gears up to 240 mph. In addition Erik will remove the forward shaft for the all wheel drive. Less weight, less gears, less friction, no modification to the oil pan...

Now I can work on a decent engine configuration based on somewhat reasonable LS redlines.

Fran confirmed that the new Graziano transaxles will ship next week. For those who are waiting for the backorders to be send out like I do.

Cheers

 

[Stephan E.]

If someone is interested here is the contact info

Graziano Drop Gear sets and service

The Race Line
Erik Johnson
P:720-899-6005
[email protected]

Dual friction, Kevlar or Ceramic clutches for the Graziano reasonably priced are available

at www.gte-engineering.com
P:754-205-0812

 

[Ken Roberts]

How much does he charge for the service?

Does this drop gear addition and forward shaft removal void the factory warranty?

 

[Stephan E.]

How much does he charge for the service?

Does this drop gear addition and forward shaft removal void the factory warranty?

Hello Ken,

Thank you for reaching out. It will void the warranty, no doubt. The gears are $2000.00 and $1000.00 for the labor, machining of the housing to accommodate the larger gears and resealing. I have decided to give it a shot.

Cheers,

Stephan

 

[Randy V]

Would you like me to merge both of your threads under this one? I could also re-title your other thread.

 

[Stephan E.]

Would you like me to merge both of your threads under this one? I could also re-title your other thread.

Thank you Randy. That would be wonderful. Please use the "Build Log" version if you can. If not that is fine too.

I appreciate your help!

Cheers,

Stephan

 

[HCF - John]

Stephan,

The drop gears Erik is selling don't deliver the outcome you are expecting. I question whether Erik has actually installed a set - he has a reputation for being a great salesman, and I'll leave it at that.

In a couple weeks I'll put together a post outlining all the math, along with conversations I've had with the head of Motorsports for Audi and ultimately an engineer in Germany for the R8 platform late last year on what's up with the ratios.

I have a set of these installed in a running/driving SLC - I believe the first to do so in an SLC - and the end result is not what you're expecting. I'd like to save you from going down the same path of frustration I did. If you can delay the decision a few weeks, I'd recommend it.

Best,
John

Welcome back under a new subject line.

I was able to secure one of the Graziano V8 drop gears from Erik at In Line Racing. We did the math today and the changes are really better suited than the V10 gear ratio. The new ratio will be 1:0.76 and will provide a sweet ride during all gears up to 240 mph. In addition Erik will remove the forward shaft for the all wheel drive. Less weight, less gears, less friction, no modification to the oil pan...

Now I can work on a decent engine configuration based on somewhat reasonable LS redlines.

Fran confirmed that the new Graziano transaxles will ship next week. For those who are waiting for the backorders to be send out like I do.

Cheers

 

[Stephan E.]

Hello fellow club members,

I received some good news from Infinitybox. I spoke to them about my backordered SLC kit last week. From what I was told the harnesses were ready and the cells are
being finished this week. Very nice people to deal with. Let's hope it will ship next week, I really need it to get going.

 

[Del]

Congrats on the car, I'm envious and can't wait to make my build log in a couple of months! Have any more pictures of the car? What wheels did you go with? Pictures of the carbon fiber tub?

 

[Stephan E.]

Hey Del,

Thanks and congrats to you. I am in the process of designing a website, maybe even a Facebook page dedicated to my build. I can post chronologically, categorize plus I am able to add all kind of information. On here is kind of all over the place. Also technical information will be much easier to find. As soon it is up I'll post the URL. I will see what pictures I have on the wheels and the tub.

 

[Del]

Hey Del,

Thanks and congrats to you. I am in the process of designing a website, maybe even a Facebook page dedicated to my build. I can post chronologically, categorize plus I am able to add all kind of information. On here is kind of all over the place. Also technical information will be much easier to find. As soon it is up I'll post the URL. I will see what pictures I have on the wheels and the tub.

Thank you. You have a good idea about a website, I considered that too and even got a domain. But I kind of like the FB idea better for simplicity and people can easily follow you and won't have to junk up your main page, not that it matters.... I know I'm proud of my purchase!

 

[Terry Oxandale]

Re: Stephan's SLC Build Threat

careful with the ITBs - i went down that path on my built LS3 and ultimately spent a crap load of money on them & peripherals and ended up selling them.

no matter what we did the car would only idle properly with ~0-3* of timing, meaning headers were glowing cherry red after idling for 4-5 seconds.

i chatted with multiple LS guys using ITBs and everybody had the same issue - some gave up on them, others used them and dealt with the problems like burnt head gaskets, and others who were using them in race motors (i.e., go all the time, no idle) were okay with it.

i completely agree with the saying that the happiest day of your life is when you unbox a set of ITBs and stick them on your engine, then the next happiest day is when you remove them and put on a normal intake manifold.

This is interesting, and makes me wonder if the problem is the fuel management systems used, and not the ITB set-up itself. I run 48mm ITBs with the Holley system on my LS2, and it works perfectly on the street (idle all the way to WOT) where this car sees most of its miles. It is configurable for every conceivable application (even allows a hybrid later 58x crank, with earlier 1x cam on inputs) I could imagine, and some I couldn't imagine. The more I learned about the programming, the more impressed I am with the product...but it took a lot of reading to understand what all the configurations meant (especially startup related parameters) to the performance of the motor.

 

[Stephan E.]

Thank you Terry,

What ITB system are you using? I have seen Jenvey, Borla and Kinsler ITB using the Holley ECM, but only in racing. Not much street applications around. I have to look who is in my neighborhood being able to tune it.

Cheers,