Fitting TTR Competition headers and Engine Mounts

[rgh0]

I had an engine mount fail at the last race meeting at Philip Island so I finally decided to fit the TTR competition ones that I have had sitting on the shelf for a year or so. Unfortunately I discovered the new TTR exhaust mount would not fit with my locally made headers that ran both sides of the exhaust as the TTR mount is slightly wider and has a through bolt which hit the existing headers boths sides.

mmmm - Looks like its time to also fit the TTR competition exhaust as well that has been sitting on shelf just as long.

Fast forward about 4 weeks and after lots of adjustments and bolt hole filing and fitting of shims I get the headers fitting the head, the mounts fitting the block, the headers clearing the body and the engine mounts aligned with the chassis. I also had to make the chassis cutout larger to clear the headers.

The biggest challenge was the clearance between the No4 exhaust header pipe and the body at the footwell and firewall. Had to move the engine about 6mm forward and about 4 mm to the right to get about 6mm clearance of the headers with the body at the tightest point. I figure with the ceramic coated headers and heat shielding on the body 6mm is enough

cheers
Rohan

[elancoupe]

I just did the same routine with the TTR headers. As you said, more space for the #4 pipe is needed. I considered shifting the motor a bit, but decided to clearance the footbox instead. In the end, I have about the same clearance as you, after adding a double layer of heat shielding. I used a reflective adhesive mounted material on the footbox and firewall, and put a piece of Thermo Tec Micro Louver shielding over top on the footbox.

I already have the TTR chassis, so notching it was not needed.

I found that my 1-4 primary was problematic. It had to have a notch put in to clear one of the hex plugs in the head, but worse, it was too narrow between the flanges, and would not fit over the studs. A visit to Dr Porto Power solved this issue. I am unsure if this was distortion from welding, or a faulty jig.

As an aside, when I bought this header (manifold) last fall, TTR told me that this was about the last one that was on hand, as the gent who makes them had retired, and they would need to source them elsewhere.

I elected to use all (short) stainless studs, with k nuts. A couple of them are a real PITA to access for tightening. I also added a bung in the collector for the (future) use of a wideband O2 sensor.

I too had mine ceramic coated.

[65ginetta]

I'm following your lead on TT exhaust fitting and would appreciate your opinion on my chassis cut out size.I made the cutout length to extend to gear box bell housing bolts to be sure of clearance but wasn't sure about how deep to make the cut out. Its easy to alter based on your advise before I get too far ahead.

[rgh0]

You should have plenty of room with that cut out.
The headers run parallel with the engine and with the frame opening up towards the front you need less cut out at the engine mount end than at the block to bell housing end.

I used as usual socket headed setscrews with nickel loctite antisieze to fix the headers to the head. With the tight clearance to the body i would have struggled to get the No4 headers over any sort of studs. A little harder to start them in the head with the header in place compared to nuts on studs but once thats done its very easy to do them up with a ball headed hex key as you can reach straight in to tighten them.

regards
Rohan

[cabc26b]

I ran into a lot of the same problems - trimming back the studs was the route we took, plus I think we had an issue with one of the bell housing bolts - ceramic coating and insulating the foot box has worked well.

George

[elansprint71]

Presumably you folks will feed back the list of problems to TT?

What series are you running these cars in? I can't see that any UK series which stipulates "period modifications only" (whatever that means) would pass your cars through scrutineering.

[Old English White]

Presumably you folks will feed back the list of problems to TT?

What series are you running these cars in? I can't see that any UK series which stipulates "period modifications only" (whatever that means) would pass your cars through scrutineering.

Pete,
These mods are pretty common on FIA GTS/10 cars...
The TTR race engine mounts are really stricly "for track race only" and the TTR 26R chassis has already the frame mod.
On the shell, you better have to cut a slice(2.5cm) on the fiberglass footwell area in order to allow some space ...
This added to an good insulation ... ally Nimbus heat shield works well
http://www.nimbusmotorsport.com/prodsho ... tegory=252
I have this header on "OEW" , great to run the car with, but the meccanics hate it!
Christian.

[65ginetta]

Christian
Do you have a picture of your footwell mod or some dimensions and location? I'm currently repairing my body ready for paint and now would be a good time to replicate your mod.

[rgh0]

Exhaust systems in the Historic racing class i run in Australia are free so no trouble with the TTR system. But as the class is for "production sports car" they must not have body modifications thus I need to leave the footwells as part of the body standard. It will be interesting to see how much more engine NVH comes through with the TTR competition mounts

regards
Rohan

[Dag-Henning]

- I have been running the TTR "big bore" , but have modified the nbr. 4 tube a bit against the head. The direction against the flange is not really terrific ...... Furthermore, the use of unbraco bolts vs. studs as Rohan says, works great ! A little hole from the footwell gives good access to the aft bolt....

[rgh0]

Hi Dag

Rather than a hole in the footwell to access the rear socket heads I jack up the engine after disconnection of the exhaust engine mount so I can get an easy straight access above the footwell

cheers
Rohan

[Dag-Henning]

- will try that one ! Thanks !

[Gray]

Hi

Has anyone tried the TTR manifold with a Spyder spaceframe chassis?

Regards Gray

[rgh0]

Based on the clearances in the Spyder spaceframe in my plus 2 I would expect it to fit without issue or modification to the space frame as it does not have the wide top lip like the Lotus version that required a cutout to clear the headers

regards
Rohan

[garyeanderson]

post47266.html#p47266
elan-f14/twin-cam-header-t989.html

Bill Gavin has a Spyder tubular chassis and the TTR exhaust and wrote a bit about it in the above links.

Gary