| Issue #5 - Last of 1999 |
In this issue |
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| Page 1 |
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The lastest rantings from the editor. [more]
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| Mike Ross' Spit 6 |
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Mike is in the process of building a highly modified Spit 6, with a lot of interesting upgrades. Does a turbocharged TR6 engine grab your attention? It grabbed mine! [more]
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| Christian Philipp's GT6 Restoration |
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Christian purchased his GT6 (named "Floyd") 5 years ago as a restoration project. He finished the restoration, and is now progressing to the next step - improvements... [more]
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| Andy Gascoigne's GT6 |
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Andy read Andrew Stark's story in Issue 3 and was inspired to tell me about his trials & tribulations of Triumph ownership. [more]
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| Your Stuff |
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Reader contributions - letters, photos, etc.[more]
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- [back to new format] -
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| Triumph GT6 Ezine |
Article - Mike Ross' Spit 6 |
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Author: Mike Ross Editor: Todd Wilson
Mike sent me the following email (in mid-May mind you), and I thought it would be a good one to share with you all.
Hi Todd,
I've enjoyed reading information on your site for months now and have gotten
a lot of ideas. I purchased a '68 Spitfire last October with plans for a
simple restoration. The body is in great shape and the engine starts up
without hesitation, though it does smoke a lot. My son and I had been
modifying his '92 Mazda Miata by adding a large Greddy turbocharger with the
help of Turbonetics (http://turbonetics.com) and Bell Engineering
(http://www.bellengineering.net). The phenomenal power and response we
obtained was too much to ignore.
In December I bought a '69 GT6 which has a great chassis, engine and
drivetrain. The body is shot so the obvious next step was to put my good
Spitfire body on my good GT6 chassis. I began dreaming about turbocharging
my GT6 engine. I figured that the GT6 transmission and differential may not
be able to handle the extra torque. Then I read a series of articles in
Grassroots Motorsports magazine (http://www.grmotorsports.com) about putting a
Mazda Rotary engine and adapting an RX7 limited slip differential to a
Spitfire chassis and a GT6 rear suspension. They used the RX7 differential
because the GT6 differential wouldn't be able to handle the added torque and
they wanted LSD for better cornering during autocross racing. They also
upgraded the transmission to a 5 speed Mazda gearbox. This really sparked my
imagination!
About this time I saw the link on your web site
(http://www.conversioncomp.co.nz) for a company in New Zealand that
fabricates a conversion kit for 5 speed Toyota transmissions to mate with
GT6 or TR6 engines. Next I was talking over the telephone with Corky Bell
of Bell engineering about my project and how pleased we were with the
turbocharger combination he designed for my son's Miata. He waxed nostalgic
about those "great old British cars". Then he said he could design and
provide components to convert either my GT6 or a TR6 engine to Electronic
Fuel Injection and Turbocharge it with intercooler etc..
Then I met a fellow in Pandora, Ohio (I live near Dayton, Ohio, USA), Ted
Schumacher from TSI Automotive (http://www.tsimportedautomotive.com/)
who's nearly convinced me to put a TR6 engine on my GT6 frame. Though he
wasn't thrilled with the idea of turbocharging the engine he too had read
the Motorsport Magazine article about the Rotary Spitfire. He thought the
TR7 rearend adaptation was too complicated and thought a Datsun Limited Slip
rear end would be easier to adapt to the GT6 chassis and drivetrain. He had
a Datsun 510 differential in his parts yard. I measured it up and it would
be relatively easy to adapt to the GT6. The Datsun differential housing is
iron rather than aluminum and has numerous mounting bolts since it is
evidently used in several different Datsun models. Ted said that he could
modify it internally using Datsun parts to make it LSD. He also was against
getting a Toyota transmission all the way from New Zealand. His
recommendation was to use a Datsun 280Z or similar 5 Datsun 5 speed
transmission adapted to a TR6 engine. He had a plan to fabricate a kit to
provide a rear engine mounting plate to adapt the Datsun bell housing to the
engine and the Datsun clutch to the TR6 flywheel. He had never done it
before and my car would be the test subject. I would also have to find a
machine shop locally to fabricate the parts.
After reading numerous posts on the web about Datsun and Toyota
transmissions, it appears that the Toyota may have the edge. As for the
differential, I did find several references to using a modified Datsun 510
LSD differential (http://dimequarterly.tierranet.com/articles/readers_dime_2_3.html) . I'm
not sure that the 510 rear end is up to a potential gross 250 bhp. that a
turbocharged, fuel injected TR6 engine could deliver. I read posts,
however, in which a race driver claimed 200+ bhp with no problems using the
Datsun 510 style differential. Actually this differential is a model R160.
The R160 recommended is a LSD model found in several Subaru's. In
particular, the '88 Subaru XT Turbo was used with gears from a '90 Legacy.
Evidently I need to look around the salvage yards for Subaru rear ends.
Incidentally, this particular 510 racer uses a Nissan Comp close ratio
5-speed transmission with overdrive. I'll have to research the Toyota vs.
Nissan transmission some more.
I went to a local salvage yard to measure up a Nissan 300ZX differential. I
read that the 300ZX Turbo used an R200 LSD in '87, '88 and '89. The
measurements were not as favorable as the Datsun 510 housing and the 300ZX
Turbo is hard to find. Also, the half axles of the 300ZX rear end looked
like they would be more difficult to join to the GT6 hubs. I found the same
problem with the 280ZX R180 differentials.
I'm still researching and only doing minor repairs until I nail down just
which components to use, i.e.: GT6 or TR6 engine and Toyota or Datsun
transmission?
I'll keep in touch as things progress. If you or your readers have any
recommendations or experience that may be helpful, please email me.
In the meantime I've attached a photo of my Spitfire and a diagram of the
GT6 differential and Datsun 510 differential I made from sketch drawn in the
salvage yard at TSI Automotive.
Best regards,
Mike
Update
I thought I'd send you an update on my project. I've purchased a TR6 engine
from a very knowledgeable source. Lawton "Lanky" Foushee from North Carolina,
USA had rebuilt the TR6 engine with new cams & lifters, new oil pump, new
rocker shaft and plugs, new ring gear and resurfaced flywheel, new forged
pistons w/ top ring gaps widened to 3/16 inch as specified by Corky Bell of
Bell Engineering to withstand Turbocharging. Rebuilt polished and ported
cylinder head w/ hardened valve seats (ready for unleaded gas) and stainless
steel exhaust valves for the increased heat generated by a turbocharger.
The block, head and related parts were hot tanked and magnifluxed. It has a
new clutch and rebuilt carbs. This engine has been run for 2 hours on a test
stand for initial break-in. It comes complete, ready to bolt in and start
with alternator, starter, heater valve etc..
I met Mr. Foushee recently at the Mid Ohio Racecourse where there were a
series of Vintage British Car Races. Mr. Foushee was Crew Chief for the
TR6 team that won the race between Triumphs and MG's. His team's white TR6
came in first and a Spitfire came in second. It was great to see the
Triumphs beat the MG's soundly.
Visit Mike Ross' Spit6 site
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Next Issue - Whatever I can lay my hands on...
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