Some fun testing - motec sidewinder

[ClutchMaster]

You’re correct in most cases overlap doesn’t help with a boosted engine. That said, overlap and duration are two different measurements in a cam. You can increase duration without affecting overlap. This cam grind actually has more duration and less overlap than stock.

Actually the overlap on our double overhead camshafts, is determined by orientation of the cam sprockets on the gears. You can slot the cam gears bolt holes and change the overlap of the camshafts.

It’s a good idea to tack the Welch plugs and cams. On occasion the plugs will pop out from oil pressure inside the cams. I wanted the cams locked in place, just felt like the thing to do.

 

[Brent68]

So this is the final tune on pump gas. Clutching struggles are finally fixed with the TAPP clutch. Here’s a pic of typical launch with the TAPP. Also included a log file to show how flat the shift RPM holds. Big props to Tommcat for a perfectly set up clutch. I bolted it on and this was the result.

 

[ClutchMaster]

So is that 20 psi boost with pump gas?
Nice smooth clutching!
Congratulations!
Hp estimated?

 

[Brent68]

So is that 20 psi boost with pump gas?
Nice smooth clutching!
Congratulations!
Hp estimated?

Yes 20 psi on pump gas. Based on injector duty cycle and and fuel pressure it’s about 360 hp.

 

[68gmc]

So this is the final tune on pump gas. Clutching struggles are finally fixed with the TAPP clutch. Here’s a pic of typical launch with the TAPP. Also included a log file to show how flat the shift RPM holds. Big props to Tommcat for a perfectly set up clutch. I bolted it on and this was the result.View attachment 152316

Here are a couple logs from my stock turbo Precision EFI Stage 4 sled and MCX Winder with 19t Mitsu turbo and Motec. Both are on 91 pump and and PEFI runs 18psi with very aggressive timing and Motec is running lower timing at higher boost level. HP estimate on PEFI sled is 320 and MCX Motec is 340. Both are awesome sleds in their own right. Always nice to be able to log and analyze different setups.

 

[Brent68]

Here are a couple logs from my stock turbo Precision EFI Stage 4 sled and MCX Winder with 19t Mitsu turbo and Motec. Both are on 91 pump and and PEFI runs 18psi with very aggressive timing and Motec is running lower timing at higher boost level. HP estimate on PEFI sled is 320 and MCX Motec is 340. Both are awesome sleds in their own right. Always nice to be able to log and analyze different setups.

Thanks for sharing. Very good logs. Both sleds look like they are running awesome! Great job on getting 250kpa on pump fuel. I’m done at 242. I have to pull too much timing with more boost. Ends up loosing rpm, i might have a slightly higher compression ratio? Are you running stock clutches?

 

[68gmc]

Thanks for sharing. Very good logs. Both sleds look like they are running awesome! Great job on getting 250kpa on pump fuel. I’m done at 242. I have to pull too much timing with more boost. Ends up loosing rpm, i might have a slightly higher compression ratio? Are you running stock clutches?

Stock clutches on PEFI sled and Tapp primary with stock secondary on Motec sled.

 

[NYTurbo]

A little off topic but 68GMC I think I read some where that you ran a 3 in tube from your air filter to your turbo ? If so do you have any pictures on how you got around the steering column ?

 

[68gmc]

A little off topic but 68GMC I think I read some where that you ran a 3 in tube from your air filter to your turbo ? If so do you have any pictures on how you got around the steering column ?

No, my setup uses MCX's silicone hose to go from filter to turbo inlet and it is stock diameter to clear steering column.

 

[Brent68]

A little off topic but 68GMC I think I read some where that you ran a 3 in tube from your air filter to your turbo ? If so do you have any pictures on how you got around the steering column ?

Mine does use 3” pipe. It is Martin’s design at Precision. Sorry but don’t have any pictures of it, other than what’s in this thread on page 2.

 

[NYTurbo]

No, my setup uses MCX's silicone hose to go from filter to turbo inlet and it is stock diameter to clear steering column.

Be nice to see this one . pretty tight around the column . Checked MCXs site but there isnt much there

 

[sledding rocks]

So this is the final tune on pump gas. Clutching struggles are finally fixed with the TAPP clutch. Here’s a pic of typical launch with the TAPP. Also included a log file to show how flat the shift RPM holds. Big props to Tommcat for a perfectly set up clutch. I bolted it on and this was the result.View attachment 152316

how r u liking the tap clutch vs stock clutches ? can u explain , thanks

 

[Brent68]

how r u liking the tap clutch vs stock clutches ? can u explain , thanks

I really like it so far, exceeding expectations. Here’s the reason I decided to get it and results:
1. I couldn’t get the stock clutch to hold shift rpm. It would WAY over shift with any loss of traction. I had help from the best clutch guys on this site, Knapp and Clutchmaster, they helped get it a lot closer. I have box of springs and helix combos if anyone wants them. TAPP doesn’t over shift like the stock primary. Exceeded expectations.
2. This sled is set up as a lake racer (short distance). I need engagement to be at least 4000 at launch with no belt slip. I’m using 2 step set at 10 psi. The stock clutch wouldn’t handle this and in my opinion is an unnecessary safety risk of coming apart. The TAPP works great.
3. The maintenance on the stock primary was high. I had the arms at 95+ grams and the rollers would last less than 500 miles.
4. The stock primary ran hot. This year in testing I blew two belts. The failures were heat related, from belt slipping. The TAPP runs significantly cooler. I gave the belt a thrashing this weekend and it held together.
5. I hated the clutch rattle. TAPP is super quiet.
6. They look cool. .

 

[sledding rocks]

I really like it so far, exceeding expectations. Here’s the reason I decided to get it and results:
1. I couldn’t get the stock clutch to hold shift rpm. It would WAY over shift with any loss of traction. I had help from the best clutch guys on this site, Knapp and Clutchmaster, they helped get it a lot closer. I have box of springs and helix combos if anyone wants them. TAPP doesn’t over shift like the stock primary. Exceeded expectations.
2. This sled is set up as a lake racer (short distance). I need engagement to be at least 4000 at launch with no belt slip. I’m using 2 step set at 10 psi. The stock clutch wouldn’t handle this and in my opinion is an unnecessary safety risk of coming apart. The TAPP works great.
3. The maintenance on the stock primary was high. I had the arms at 95+ grams and the rollers would last less than 500 miles.
4. The stock primary ran hot. This year in testing I blew two belts. The failures were heat related, from belt slipping. The TAPP runs significantly cooler. I gave the belt a thrashing this weekend and it held together.
5. I hated the clutch rattle. TAPP is super quiet.
6. They look cool. .

thanks for your reply , im also considering going with Tapp , a friend of mine has it in his turbo 1200 doo motec set up by Martin , the sled is amazing fast on pump gas , the Tapp clutch works great at all times and cool to touch , he's using a xs belt from timken also , what belt r u using with your set up ? yes the stock clutch eat roller once u put hp to it , I had the same issue last season with 300hp , 500 miles new rollers , thanks for all the info

 

[Brent68]

thanks for your reply , im also considering going with Tapp , a friend of mine has it in his turbo 1200 doo motec set up by Martin , the sled is amazing fast on pump gas , the Tapp clutch works great at all times and cool to touch , he's using a xs belt from timken also , what belt r u using with your set up ? yes the stock clutch eat roller once u put hp to it , I had the same issue last season with 300hp , 500 miles new rollers , thanks for all the info

8DN for me.